diff options
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 5978 |
1 files changed, 1884 insertions, 4094 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ab457f0394ab..be810c1fbfc3 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -25,14 +25,16 @@ * Copyright (C) 2020 Alibaba, Inc, Alex Shi */ +#include <linux/cgroup-defs.h> #include <linux/page_counter.h> #include <linux/memcontrol.h> #include <linux/cgroup.h> -#include <linux/pagewalk.h> +#include <linux/cpuset.h> #include <linux/sched/mm.h> #include <linux/shmem_fs.h> #include <linux/hugetlb.h> #include <linux/pagemap.h> +#include <linux/pagevec.h> #include <linux/vm_event_item.h> #include <linux/smp.h> #include <linux/page-flags.h> @@ -41,15 +43,12 @@ #include <linux/rcupdate.h> #include <linux/limits.h> #include <linux/export.h> +#include <linux/list.h> #include <linux/mutex.h> #include <linux/rbtree.h> #include <linux/slab.h> -#include <linux/swap.h> #include <linux/swapops.h> #include <linux/spinlock.h> -#include <linux/eventfd.h> -#include <linux/poll.h> -#include <linux/sort.h> #include <linux/fs.h> #include <linux/seq_file.h> #include <linux/vmpressure.h> @@ -59,25 +58,30 @@ #include <linux/cpu.h> #include <linux/oom.h> #include <linux/lockdep.h> -#include <linux/file.h> #include <linux/resume_user_mode.h> #include <linux/psi.h> #include <linux/seq_buf.h> -#include <linux/parser.h> +#include <linux/sched/isolation.h> +#include <linux/kmemleak.h> #include "internal.h" #include <net/sock.h> #include <net/ip.h> #include "slab.h" -#include "swap.h" +#include "memcontrol-v1.h" #include <linux/uaccess.h> +#define CREATE_TRACE_POINTS +#include <trace/events/memcg.h> +#undef CREATE_TRACE_POINTS + #include <trace/events/vmscan.h> struct cgroup_subsys memory_cgrp_subsys __read_mostly; EXPORT_SYMBOL(memory_cgrp_subsys); struct mem_cgroup *root_mem_cgroup __read_mostly; +EXPORT_SYMBOL(root_mem_cgroup); /* Active memory cgroup to use from an interrupt context */ DEFINE_PER_CPU(struct mem_cgroup *, int_active_memcg); @@ -89,144 +93,16 @@ static bool cgroup_memory_nosocket __ro_after_init; /* Kernel memory accounting disabled? */ static bool cgroup_memory_nokmem __ro_after_init; +/* BPF memory accounting disabled? */ +static bool cgroup_memory_nobpf __ro_after_init; + +static struct kmem_cache *memcg_cachep; +static struct kmem_cache *memcg_pn_cachep; + #ifdef CONFIG_CGROUP_WRITEBACK static DECLARE_WAIT_QUEUE_HEAD(memcg_cgwb_frn_waitq); #endif -/* Whether legacy memory+swap accounting is active */ -static bool do_memsw_account(void) -{ - return !cgroup_subsys_on_dfl(memory_cgrp_subsys); -} - -#define THRESHOLDS_EVENTS_TARGET 128 -#define SOFTLIMIT_EVENTS_TARGET 1024 - -/* - * Cgroups above their limits are maintained in a RB-Tree, independent of - * their hierarchy representation - */ - -struct mem_cgroup_tree_per_node { - struct rb_root rb_root; - struct rb_node *rb_rightmost; - spinlock_t lock; -}; - -struct mem_cgroup_tree { - struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES]; -}; - -static struct mem_cgroup_tree soft_limit_tree __read_mostly; - -/* for OOM */ -struct mem_cgroup_eventfd_list { - struct list_head list; - struct eventfd_ctx *eventfd; -}; - -/* - * cgroup_event represents events which userspace want to receive. - */ -struct mem_cgroup_event { - /* - * memcg which the event belongs to. - */ - struct mem_cgroup *memcg; - /* - * eventfd to signal userspace about the event. - */ - struct eventfd_ctx *eventfd; - /* - * Each of these stored in a list by the cgroup. - */ - struct list_head list; - /* - * register_event() callback will be used to add new userspace - * waiter for changes related to this event. Use eventfd_signal() - * on eventfd to send notification to userspace. - */ - int (*register_event)(struct mem_cgroup *memcg, - struct eventfd_ctx *eventfd, const char *args); - /* - * unregister_event() callback will be called when userspace closes - * the eventfd or on cgroup removing. This callback must be set, - * if you want provide notification functionality. - */ - void (*unregister_event)(struct mem_cgroup *memcg, - struct eventfd_ctx *eventfd); - /* - * All fields below needed to unregister event when - * userspace closes eventfd. - */ - poll_table pt; - wait_queue_head_t *wqh; - wait_queue_entry_t wait; - struct work_struct remove; -}; - -static void mem_cgroup_threshold(struct mem_cgroup *memcg); -static void mem_cgroup_oom_notify(struct mem_cgroup *memcg); - -/* Stuffs for move charges at task migration. */ -/* - * Types of charges to be moved. - */ -#define MOVE_ANON 0x1U -#define MOVE_FILE 0x2U -#define MOVE_MASK (MOVE_ANON | MOVE_FILE) - -/* "mc" and its members are protected by cgroup_mutex */ -static struct move_charge_struct { - spinlock_t lock; /* for from, to */ - struct mm_struct *mm; - struct mem_cgroup *from; - struct mem_cgroup *to; - unsigned long flags; - unsigned long precharge; - unsigned long moved_charge; - unsigned long moved_swap; - struct task_struct *moving_task; /* a task moving charges */ - wait_queue_head_t waitq; /* a waitq for other context */ -} mc = { - .lock = __SPIN_LOCK_UNLOCKED(mc.lock), - .waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq), -}; - -/* - * Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft - * limit reclaim to prevent infinite loops, if they ever occur. - */ -#define MEM_CGROUP_MAX_RECLAIM_LOOPS 100 -#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2 - -/* for encoding cft->private value on file */ -enum res_type { - _MEM, - _MEMSWAP, - _KMEM, - _TCP, -}; - -#define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val)) -#define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff) -#define MEMFILE_ATTR(val) ((val) & 0xffff) - -/* - * Iteration constructs for visiting all cgroups (under a tree). If - * loops are exited prematurely (break), mem_cgroup_iter_break() must - * be used for reference counting. - */ -#define for_each_mem_cgroup_tree(iter, root) \ - for (iter = mem_cgroup_iter(root, NULL, NULL); \ - iter != NULL; \ - iter = mem_cgroup_iter(root, iter, NULL)) - -#define for_each_mem_cgroup(iter) \ - for (iter = mem_cgroup_iter(NULL, NULL, NULL); \ - iter != NULL; \ - iter = mem_cgroup_iter(NULL, iter, NULL)) - static inline bool task_is_dying(void) { return tsk_is_oom_victim(current) || fatal_signal_pending(current) || @@ -246,7 +122,10 @@ struct mem_cgroup *vmpressure_to_memcg(struct vmpressure *vmpr) return container_of(vmpr, struct mem_cgroup, vmpressure); } -#ifdef CONFIG_MEMCG_KMEM +#define SEQ_BUF_SIZE SZ_4K +#define CURRENT_OBJCG_UPDATE_BIT 0 +#define CURRENT_OBJCG_UPDATE_FLAG (1UL << CURRENT_OBJCG_UPDATE_BIT) + static DEFINE_SPINLOCK(objcg_lock); bool mem_cgroup_kmem_disabled(void) @@ -254,8 +133,7 @@ bool mem_cgroup_kmem_disabled(void) return cgroup_memory_nokmem; } -static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, - unsigned int nr_pages); +static void memcg_uncharge(struct mem_cgroup *memcg, unsigned int nr_pages); static void obj_cgroup_release(struct percpu_ref *ref) { @@ -288,8 +166,16 @@ static void obj_cgroup_release(struct percpu_ref *ref) WARN_ON_ONCE(nr_bytes & (PAGE_SIZE - 1)); nr_pages = nr_bytes >> PAGE_SHIFT; - if (nr_pages) - obj_cgroup_uncharge_pages(objcg, nr_pages); + if (nr_pages) { + struct mem_cgroup *memcg; + + memcg = get_mem_cgroup_from_objcg(objcg); + mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages); + memcg1_account_kmem(memcg, -nr_pages); + if (!mem_cgroup_is_root(memcg)) + memcg_uncharge(memcg, nr_pages); + mem_cgroup_put(memcg); + } spin_lock_irqsave(&objcg_lock, flags); list_del(&objcg->list); @@ -342,30 +228,30 @@ static void memcg_reparent_objcgs(struct mem_cgroup *memcg, /* * A lot of the calls to the cache allocation functions are expected to be - * inlined by the compiler. Since the calls to memcg_slab_pre_alloc_hook() are + * inlined by the compiler. Since the calls to memcg_slab_post_alloc_hook() are * conditional to this static branch, we'll have to allow modules that does * kmem_cache_alloc and the such to see this symbol as well */ -DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); -EXPORT_SYMBOL(memcg_kmem_enabled_key); -#endif +DEFINE_STATIC_KEY_FALSE(memcg_kmem_online_key); +EXPORT_SYMBOL(memcg_kmem_online_key); + +DEFINE_STATIC_KEY_FALSE(memcg_bpf_enabled_key); +EXPORT_SYMBOL(memcg_bpf_enabled_key); /** - * mem_cgroup_css_from_page - css of the memcg associated with a page - * @page: page of interest + * mem_cgroup_css_from_folio - css of the memcg associated with a folio + * @folio: folio of interest * * If memcg is bound to the default hierarchy, css of the memcg associated - * with @page is returned. The returned css remains associated with @page + * with @folio is returned. The returned css remains associated with @folio * until it is released. * * If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup * is returned. */ -struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page) +struct cgroup_subsys_state *mem_cgroup_css_from_folio(struct folio *folio) { - struct mem_cgroup *memcg; - - memcg = page_memcg(page); + struct mem_cgroup *memcg = folio_memcg(folio); if (!memcg || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) memcg = root_mem_cgroup; @@ -392,7 +278,8 @@ ino_t page_cgroup_ino(struct page *page) unsigned long ino = 0; rcu_read_lock(); - memcg = page_memcg_check(page); + /* page_folio() is racy here, but the entire function is racy anyway */ + memcg = folio_memcg_check(page_folio(page)); while (memcg && !(memcg->css.flags & CSS_ONLINE)) memcg = parent_mem_cgroup(memcg); @@ -401,271 +288,167 @@ ino_t page_cgroup_ino(struct page *page) rcu_read_unlock(); return ino; } +EXPORT_SYMBOL_GPL(page_cgroup_ino); + +/* Subset of node_stat_item for memcg stats */ +static const unsigned int memcg_node_stat_items[] = { + NR_INACTIVE_ANON, + NR_ACTIVE_ANON, + NR_INACTIVE_FILE, + NR_ACTIVE_FILE, + NR_UNEVICTABLE, + NR_SLAB_RECLAIMABLE_B, + NR_SLAB_UNRECLAIMABLE_B, + WORKINGSET_REFAULT_ANON, + WORKINGSET_REFAULT_FILE, + WORKINGSET_ACTIVATE_ANON, + WORKINGSET_ACTIVATE_FILE, + WORKINGSET_RESTORE_ANON, + WORKINGSET_RESTORE_FILE, + WORKINGSET_NODERECLAIM, + NR_ANON_MAPPED, + NR_FILE_MAPPED, + NR_FILE_PAGES, + NR_FILE_DIRTY, + NR_WRITEBACK, + NR_SHMEM, + NR_SHMEM_THPS, + NR_FILE_THPS, + NR_ANON_THPS, + NR_KERNEL_STACK_KB, + NR_PAGETABLE, + NR_SECONDARY_PAGETABLE, +#ifdef CONFIG_SWAP + NR_SWAPCACHE, +#endif +#ifdef CONFIG_NUMA_BALANCING + PGPROMOTE_SUCCESS, +#endif + PGDEMOTE_KSWAPD, + PGDEMOTE_DIRECT, + PGDEMOTE_KHUGEPAGED, + PGDEMOTE_PROACTIVE, +#ifdef CONFIG_HUGETLB_PAGE + NR_HUGETLB, +#endif +}; -static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz, - struct mem_cgroup_tree_per_node *mctz, - unsigned long new_usage_in_excess) -{ - struct rb_node **p = &mctz->rb_root.rb_node; - struct rb_node *parent = NULL; - struct mem_cgroup_per_node *mz_node; - bool rightmost = true; - - if (mz->on_tree) - return; - - mz->usage_in_excess = new_usage_in_excess; - if (!mz->usage_in_excess) - return; - while (*p) { - parent = *p; - mz_node = rb_entry(parent, struct mem_cgroup_per_node, - tree_node); - if (mz->usage_in_excess < mz_node->usage_in_excess) { - p = &(*p)->rb_left; - rightmost = false; - } else { - p = &(*p)->rb_right; - } - } - - if (rightmost) - mctz->rb_rightmost = &mz->tree_node; - - rb_link_node(&mz->tree_node, parent, p); - rb_insert_color(&mz->tree_node, &mctz->rb_root); - mz->on_tree = true; -} - -static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz, - struct mem_cgroup_tree_per_node *mctz) -{ - if (!mz->on_tree) - return; - - if (&mz->tree_node == mctz->rb_rightmost) - mctz->rb_rightmost = rb_prev(&mz->tree_node); +static const unsigned int memcg_stat_items[] = { + MEMCG_SWAP, + MEMCG_SOCK, + MEMCG_PERCPU_B, + MEMCG_VMALLOC, + MEMCG_KMEM, + MEMCG_ZSWAP_B, + MEMCG_ZSWAPPED, +}; - rb_erase(&mz->tree_node, &mctz->rb_root); - mz->on_tree = false; -} +#define NR_MEMCG_NODE_STAT_ITEMS ARRAY_SIZE(memcg_node_stat_items) +#define MEMCG_VMSTAT_SIZE (NR_MEMCG_NODE_STAT_ITEMS + \ + ARRAY_SIZE(memcg_stat_items)) +#define BAD_STAT_IDX(index) ((u32)(index) >= U8_MAX) +static u8 mem_cgroup_stats_index[MEMCG_NR_STAT] __read_mostly; -static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz, - struct mem_cgroup_tree_per_node *mctz) +static void init_memcg_stats(void) { - unsigned long flags; + u8 i, j = 0; - spin_lock_irqsave(&mctz->lock, flags); - __mem_cgroup_remove_exceeded(mz, mctz); - spin_unlock_irqrestore(&mctz->lock, flags); -} + BUILD_BUG_ON(MEMCG_NR_STAT >= U8_MAX); -static unsigned long soft_limit_excess(struct mem_cgroup *memcg) -{ - unsigned long nr_pages = page_counter_read(&memcg->memory); - unsigned long soft_limit = READ_ONCE(memcg->soft_limit); - unsigned long excess = 0; + memset(mem_cgroup_stats_index, U8_MAX, sizeof(mem_cgroup_stats_index)); - if (nr_pages > soft_limit) - excess = nr_pages - soft_limit; + for (i = 0; i < NR_MEMCG_NODE_STAT_ITEMS; ++i, ++j) + mem_cgroup_stats_index[memcg_node_stat_items[i]] = j; - return excess; + for (i = 0; i < ARRAY_SIZE(memcg_stat_items); ++i, ++j) + mem_cgroup_stats_index[memcg_stat_items[i]] = j; } -static void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid) +static inline int memcg_stats_index(int idx) { - unsigned long excess; - struct mem_cgroup_per_node *mz; - struct mem_cgroup_tree_per_node *mctz; - - mctz = soft_limit_tree.rb_tree_per_node[nid]; - if (!mctz) - return; - /* - * Necessary to update all ancestors when hierarchy is used. - * because their event counter is not touched. - */ - for (; memcg; memcg = parent_mem_cgroup(memcg)) { - mz = memcg->nodeinfo[nid]; - excess = soft_limit_excess(memcg); - /* - * We have to update the tree if mz is on RB-tree or - * mem is over its softlimit. - */ - if (excess || mz->on_tree) { - unsigned long flags; - - spin_lock_irqsave(&mctz->lock, flags); - /* if on-tree, remove it */ - if (mz->on_tree) - __mem_cgroup_remove_exceeded(mz, mctz); - /* - * Insert again. mz->usage_in_excess will be updated. - * If excess is 0, no tree ops. - */ - __mem_cgroup_insert_exceeded(mz, mctz, excess); - spin_unlock_irqrestore(&mctz->lock, flags); - } - } -} - -static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg) -{ - struct mem_cgroup_tree_per_node *mctz; - struct mem_cgroup_per_node *mz; - int nid; - - for_each_node(nid) { - mz = memcg->nodeinfo[nid]; - mctz = soft_limit_tree.rb_tree_per_node[nid]; - if (mctz) - mem_cgroup_remove_exceeded(mz, mctz); - } + return mem_cgroup_stats_index[idx]; } -static struct mem_cgroup_per_node * -__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) -{ - struct mem_cgroup_per_node *mz; +struct lruvec_stats_percpu { + /* Local (CPU and cgroup) state */ + long state[NR_MEMCG_NODE_STAT_ITEMS]; -retry: - mz = NULL; - if (!mctz->rb_rightmost) - goto done; /* Nothing to reclaim from */ - - mz = rb_entry(mctz->rb_rightmost, - struct mem_cgroup_per_node, tree_node); - /* - * Remove the node now but someone else can add it back, - * we will to add it back at the end of reclaim to its correct - * position in the tree. - */ - __mem_cgroup_remove_exceeded(mz, mctz); - if (!soft_limit_excess(mz->memcg) || - !css_tryget(&mz->memcg->css)) - goto retry; -done: - return mz; -} - -static struct mem_cgroup_per_node * -mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz) -{ - struct mem_cgroup_per_node *mz; - - spin_lock_irq(&mctz->lock); - mz = __mem_cgroup_largest_soft_limit_node(mctz); - spin_unlock_irq(&mctz->lock); - return mz; -} - -/* - * memcg and lruvec stats flushing - * - * Many codepaths leading to stats update or read are performance sensitive and - * adding stats flushing in such codepaths is not desirable. So, to optimize the - * flushing the kernel does: - * - * 1) Periodically and asynchronously flush the stats every 2 seconds to not let - * rstat update tree grow unbounded. - * - * 2) Flush the stats synchronously on reader side only when there are more than - * (MEMCG_CHARGE_BATCH * nr_cpus) update events. Though this optimization - * will let stats be out of sync by atmost (MEMCG_CHARGE_BATCH * nr_cpus) but - * only for 2 seconds due to (1). - */ -static void flush_memcg_stats_dwork(struct work_struct *w); -static DECLARE_DEFERRABLE_WORK(stats_flush_dwork, flush_memcg_stats_dwork); -static DEFINE_SPINLOCK(stats_flush_lock); -static DEFINE_PER_CPU(unsigned int, stats_updates); -static atomic_t stats_flush_threshold = ATOMIC_INIT(0); -static u64 flush_next_time; + /* Delta calculation for lockless upward propagation */ + long state_prev[NR_MEMCG_NODE_STAT_ITEMS]; +}; -#define FLUSH_TIME (2UL*HZ) +struct lruvec_stats { + /* Aggregated (CPU and subtree) state */ + long state[NR_MEMCG_NODE_STAT_ITEMS]; -/* - * Accessors to ensure that preemption is disabled on PREEMPT_RT because it can - * not rely on this as part of an acquired spinlock_t lock. These functions are - * never used in hardirq context on PREEMPT_RT and therefore disabling preemtion - * is sufficient. - */ -static void memcg_stats_lock(void) -{ - preempt_disable_nested(); - VM_WARN_ON_IRQS_ENABLED(); -} + /* Non-hierarchical (CPU aggregated) state */ + long state_local[NR_MEMCG_NODE_STAT_ITEMS]; -static void __memcg_stats_lock(void) -{ - preempt_disable_nested(); -} + /* Pending child counts during tree propagation */ + long state_pending[NR_MEMCG_NODE_STAT_ITEMS]; +}; -static void memcg_stats_unlock(void) +unsigned long lruvec_page_state(struct lruvec *lruvec, enum node_stat_item idx) { - preempt_enable_nested(); -} + struct mem_cgroup_per_node *pn; + long x; + int i; -static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val) -{ - unsigned int x; + if (mem_cgroup_disabled()) + return node_page_state(lruvec_pgdat(lruvec), idx); - cgroup_rstat_updated(memcg->css.cgroup, smp_processor_id()); + i = memcg_stats_index(idx); + if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx)) + return 0; - x = __this_cpu_add_return(stats_updates, abs(val)); - if (x > MEMCG_CHARGE_BATCH) { - /* - * If stats_flush_threshold exceeds the threshold - * (>num_online_cpus()), cgroup stats update will be triggered - * in __mem_cgroup_flush_stats(). Increasing this var further - * is redundant and simply adds overhead in atomic update. - */ - if (atomic_read(&stats_flush_threshold) <= num_online_cpus()) - atomic_add(x / MEMCG_CHARGE_BATCH, &stats_flush_threshold); - __this_cpu_write(stats_updates, 0); - } + pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec); + x = READ_ONCE(pn->lruvec_stats->state[i]); +#ifdef CONFIG_SMP + if (x < 0) + x = 0; +#endif + return x; } -static void __mem_cgroup_flush_stats(void) +unsigned long lruvec_page_state_local(struct lruvec *lruvec, + enum node_stat_item idx) { - unsigned long flag; - - if (!spin_trylock_irqsave(&stats_flush_lock, flag)) - return; - - flush_next_time = jiffies_64 + 2*FLUSH_TIME; - cgroup_rstat_flush_irqsafe(root_mem_cgroup->css.cgroup); - atomic_set(&stats_flush_threshold, 0); - spin_unlock_irqrestore(&stats_flush_lock, flag); -} + struct mem_cgroup_per_node *pn; + long x; + int i; -void mem_cgroup_flush_stats(void) -{ - if (atomic_read(&stats_flush_threshold) > num_online_cpus()) - __mem_cgroup_flush_stats(); -} + if (mem_cgroup_disabled()) + return node_page_state(lruvec_pgdat(lruvec), idx); -void mem_cgroup_flush_stats_delayed(void) -{ - if (time_after64(jiffies_64, flush_next_time)) - mem_cgroup_flush_stats(); -} + i = memcg_stats_index(idx); + if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx)) + return 0; -static void flush_memcg_stats_dwork(struct work_struct *w) -{ - __mem_cgroup_flush_stats(); - queue_delayed_work(system_unbound_wq, &stats_flush_dwork, FLUSH_TIME); + pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec); + x = READ_ONCE(pn->lruvec_stats->state_local[i]); +#ifdef CONFIG_SMP + if (x < 0) + x = 0; +#endif + return x; } /* Subset of vm_event_item to report for memcg event stats */ static const unsigned int memcg_vm_event_stat[] = { +#ifdef CONFIG_MEMCG_V1 PGPGIN, PGPGOUT, +#endif + PSWPIN, + PSWPOUT, PGSCAN_KSWAPD, PGSCAN_DIRECT, PGSCAN_KHUGEPAGED, + PGSCAN_PROACTIVE, PGSTEAL_KSWAPD, PGSTEAL_DIRECT, PGSTEAL_KHUGEPAGED, + PGSTEAL_PROACTIVE, PGFAULT, PGMAJFAULT, PGREFILL, @@ -673,59 +456,206 @@ static const unsigned int memcg_vm_event_stat[] = { PGDEACTIVATE, PGLAZYFREE, PGLAZYFREED, -#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) +#ifdef CONFIG_SWAP + SWPIN_ZERO, + SWPOUT_ZERO, +#endif +#ifdef CONFIG_ZSWAP ZSWPIN, ZSWPOUT, + ZSWPWB, #endif #ifdef CONFIG_TRANSPARENT_HUGEPAGE THP_FAULT_ALLOC, THP_COLLAPSE_ALLOC, + THP_SWPOUT, + THP_SWPOUT_FALLBACK, +#endif +#ifdef CONFIG_NUMA_BALANCING + NUMA_PAGE_MIGRATE, + NUMA_PTE_UPDATES, + NUMA_HINT_FAULTS, #endif }; #define NR_MEMCG_EVENTS ARRAY_SIZE(memcg_vm_event_stat) -static int mem_cgroup_events_index[NR_VM_EVENT_ITEMS] __read_mostly; +static u8 mem_cgroup_events_index[NR_VM_EVENT_ITEMS] __read_mostly; static void init_memcg_events(void) { - int i; + u8 i; + + BUILD_BUG_ON(NR_VM_EVENT_ITEMS >= U8_MAX); + + memset(mem_cgroup_events_index, U8_MAX, + sizeof(mem_cgroup_events_index)); for (i = 0; i < NR_MEMCG_EVENTS; ++i) - mem_cgroup_events_index[memcg_vm_event_stat[i]] = i + 1; + mem_cgroup_events_index[memcg_vm_event_stat[i]] = i; } static inline int memcg_events_index(enum vm_event_item idx) { - return mem_cgroup_events_index[idx] - 1; + return mem_cgroup_events_index[idx]; } struct memcg_vmstats_percpu { + /* Stats updates since the last flush */ + unsigned int stats_updates; + + /* Cached pointers for fast iteration in memcg_rstat_updated() */ + struct memcg_vmstats_percpu __percpu *parent_pcpu; + struct memcg_vmstats *vmstats; + + /* The above should fit a single cacheline for memcg_rstat_updated() */ + /* Local (CPU and cgroup) page state & events */ - long state[MEMCG_NR_STAT]; + long state[MEMCG_VMSTAT_SIZE]; unsigned long events[NR_MEMCG_EVENTS]; /* Delta calculation for lockless upward propagation */ - long state_prev[MEMCG_NR_STAT]; + long state_prev[MEMCG_VMSTAT_SIZE]; unsigned long events_prev[NR_MEMCG_EVENTS]; - - /* Cgroup1: threshold notifications & softlimit tree updates */ - unsigned long nr_page_events; - unsigned long targets[MEM_CGROUP_NTARGETS]; -}; +} ____cacheline_aligned; struct memcg_vmstats { /* Aggregated (CPU and subtree) page state & events */ - long state[MEMCG_NR_STAT]; + long state[MEMCG_VMSTAT_SIZE]; unsigned long events[NR_MEMCG_EVENTS]; + /* Non-hierarchical (CPU aggregated) page state & events */ + long state_local[MEMCG_VMSTAT_SIZE]; + unsigned long events_local[NR_MEMCG_EVENTS]; + /* Pending child counts during tree propagation */ - long state_pending[MEMCG_NR_STAT]; + long state_pending[MEMCG_VMSTAT_SIZE]; unsigned long events_pending[NR_MEMCG_EVENTS]; + + /* Stats updates since the last flush */ + atomic_t stats_updates; }; +/* + * memcg and lruvec stats flushing + * + * Many codepaths leading to stats update or read are performance sensitive and + * adding stats flushing in such codepaths is not desirable. So, to optimize the + * flushing the kernel does: + * + * 1) Periodically and asynchronously flush the stats every 2 seconds to not let + * rstat update tree grow unbounded. + * + * 2) Flush the stats synchronously on reader side only when there are more than + * (MEMCG_CHARGE_BATCH * nr_cpus) update events. Though this optimization + * will let stats be out of sync by atmost (MEMCG_CHARGE_BATCH * nr_cpus) but + * only for 2 seconds due to (1). + */ +static void flush_memcg_stats_dwork(struct work_struct *w); +static DECLARE_DEFERRABLE_WORK(stats_flush_dwork, flush_memcg_stats_dwork); +static u64 flush_last_time; + +#define FLUSH_TIME (2UL*HZ) + +static bool memcg_vmstats_needs_flush(struct memcg_vmstats *vmstats) +{ + return atomic_read(&vmstats->stats_updates) > + MEMCG_CHARGE_BATCH * num_online_cpus(); +} + +static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val, + int cpu) +{ + struct memcg_vmstats_percpu __percpu *statc_pcpu; + struct memcg_vmstats_percpu *statc; + unsigned int stats_updates; + + if (!val) + return; + + css_rstat_updated(&memcg->css, cpu); + statc_pcpu = memcg->vmstats_percpu; + for (; statc_pcpu; statc_pcpu = statc->parent_pcpu) { + statc = this_cpu_ptr(statc_pcpu); + /* + * If @memcg is already flushable then all its ancestors are + * flushable as well and also there is no need to increase + * stats_updates. + */ + if (memcg_vmstats_needs_flush(statc->vmstats)) + break; + + stats_updates = this_cpu_add_return(statc_pcpu->stats_updates, + abs(val)); + if (stats_updates < MEMCG_CHARGE_BATCH) + continue; + + stats_updates = this_cpu_xchg(statc_pcpu->stats_updates, 0); + atomic_add(stats_updates, &statc->vmstats->stats_updates); + } +} + +static void __mem_cgroup_flush_stats(struct mem_cgroup *memcg, bool force) +{ + bool needs_flush = memcg_vmstats_needs_flush(memcg->vmstats); + + trace_memcg_flush_stats(memcg, atomic_read(&memcg->vmstats->stats_updates), + force, needs_flush); + + if (!force && !needs_flush) + return; + + if (mem_cgroup_is_root(memcg)) + WRITE_ONCE(flush_last_time, jiffies_64); + + css_rstat_flush(&memcg->css); +} + +/* + * mem_cgroup_flush_stats - flush the stats of a memory cgroup subtree + * @memcg: root of the subtree to flush + * + * Flushing is serialized by the underlying global rstat lock. There is also a + * minimum amount of work to be done even if there are no stat updates to flush. + * Hence, we only flush the stats if the updates delta exceeds a threshold. This + * avoids unnecessary work and contention on the underlying lock. + */ +void mem_cgroup_flush_stats(struct mem_cgroup *memcg) +{ + if (mem_cgroup_disabled()) + return; + + if (!memcg) + memcg = root_mem_cgroup; + + __mem_cgroup_flush_stats(memcg, false); +} + +void mem_cgroup_flush_stats_ratelimited(struct mem_cgroup *memcg) +{ + /* Only flush if the periodic flusher is one full cycle late */ + if (time_after64(jiffies_64, READ_ONCE(flush_last_time) + 2*FLUSH_TIME)) + mem_cgroup_flush_stats(memcg); +} + +static void flush_memcg_stats_dwork(struct work_struct *w) +{ + /* + * Deliberately ignore memcg_vmstats_needs_flush() here so that flushing + * in latency-sensitive paths is as cheap as possible. + */ + __mem_cgroup_flush_stats(root_mem_cgroup, true); + queue_delayed_work(system_unbound_wq, &stats_flush_dwork, FLUSH_TIME); +} + unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx) { - long x = READ_ONCE(memcg->vmstats->state[idx]); + long x; + int i = memcg_stats_index(idx); + + if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx)) + return 0; + + x = READ_ONCE(memcg->vmstats->state[i]); #ifdef CONFIG_SMP if (x < 0) x = 0; @@ -733,78 +663,101 @@ unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx) return x; } +static int memcg_page_state_unit(int item); + +/* + * Normalize the value passed into memcg_rstat_updated() to be in pages. Round + * up non-zero sub-page updates to 1 page as zero page updates are ignored. + */ +static int memcg_state_val_in_pages(int idx, int val) +{ + int unit = memcg_page_state_unit(idx); + + if (!val || unit == PAGE_SIZE) + return val; + else + return max(val * unit / PAGE_SIZE, 1UL); +} + /** - * __mod_memcg_state - update cgroup memory statistics + * mod_memcg_state - update cgroup memory statistics * @memcg: the memory cgroup * @idx: the stat item - can be enum memcg_stat_item or enum node_stat_item * @val: delta to add to the counter, can be negative */ -void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val) +void mod_memcg_state(struct mem_cgroup *memcg, enum memcg_stat_item idx, + int val) { + int i = memcg_stats_index(idx); + int cpu; + if (mem_cgroup_disabled()) return; - __this_cpu_add(memcg->vmstats_percpu->state[idx], val); - memcg_rstat_updated(memcg, val); + if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx)) + return; + + cpu = get_cpu(); + + this_cpu_add(memcg->vmstats_percpu->state[i], val); + val = memcg_state_val_in_pages(idx, val); + memcg_rstat_updated(memcg, val, cpu); + trace_mod_memcg_state(memcg, idx, val); + + put_cpu(); } +#ifdef CONFIG_MEMCG_V1 /* idx can be of type enum memcg_stat_item or node_stat_item. */ -static unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx) +unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx) { - long x = 0; - int cpu; + long x; + int i = memcg_stats_index(idx); - for_each_possible_cpu(cpu) - x += per_cpu(memcg->vmstats_percpu->state[idx], cpu); + if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx)) + return 0; + + x = READ_ONCE(memcg->vmstats->state_local[i]); #ifdef CONFIG_SMP if (x < 0) x = 0; #endif return x; } +#endif -void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, - int val) +static void mod_memcg_lruvec_state(struct lruvec *lruvec, + enum node_stat_item idx, + int val) { struct mem_cgroup_per_node *pn; struct mem_cgroup *memcg; + int i = memcg_stats_index(idx); + int cpu; + + if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx)) + return; pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec); memcg = pn->memcg; - /* - * The caller from rmap relay on disabled preemption becase they never - * update their counter from in-interrupt context. For these two - * counters we check that the update is never performed from an - * interrupt context while other caller need to have disabled interrupt. - */ - __memcg_stats_lock(); - if (IS_ENABLED(CONFIG_DEBUG_VM)) { - switch (idx) { - case NR_ANON_MAPPED: - case NR_FILE_MAPPED: - case NR_ANON_THPS: - case NR_SHMEM_PMDMAPPED: - case NR_FILE_PMDMAPPED: - WARN_ON_ONCE(!in_task()); - break; - default: - VM_WARN_ON_IRQS_ENABLED(); - } - } + cpu = get_cpu(); /* Update memcg */ - __this_cpu_add(memcg->vmstats_percpu->state[idx], val); + this_cpu_add(memcg->vmstats_percpu->state[i], val); /* Update lruvec */ - __this_cpu_add(pn->lruvec_stats_percpu->state[idx], val); + this_cpu_add(pn->lruvec_stats_percpu->state[i], val); - memcg_rstat_updated(memcg, val); - memcg_stats_unlock(); + val = memcg_state_val_in_pages(idx, val); + memcg_rstat_updated(memcg, val, cpu); + trace_mod_memcg_lruvec_state(memcg, idx, val); + + put_cpu(); } /** - * __mod_lruvec_state - update lruvec memory statistics + * mod_lruvec_state - update lruvec memory statistics * @lruvec: the lruvec * @idx: the stat item * @val: delta to add to the counter, can be negative @@ -813,41 +766,40 @@ void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, * function updates the all three counters that are affected by a * change of state at this level: per-node, per-cgroup, per-lruvec. */ -void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, +void mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, int val) { /* Update node */ - __mod_node_page_state(lruvec_pgdat(lruvec), idx, val); + mod_node_page_state(lruvec_pgdat(lruvec), idx, val); /* Update memcg and lruvec */ if (!mem_cgroup_disabled()) - __mod_memcg_lruvec_state(lruvec, idx, val); + mod_memcg_lruvec_state(lruvec, idx, val); } -void __mod_lruvec_page_state(struct page *page, enum node_stat_item idx, +void lruvec_stat_mod_folio(struct folio *folio, enum node_stat_item idx, int val) { - struct page *head = compound_head(page); /* rmap on tail pages */ struct mem_cgroup *memcg; - pg_data_t *pgdat = page_pgdat(page); + pg_data_t *pgdat = folio_pgdat(folio); struct lruvec *lruvec; rcu_read_lock(); - memcg = page_memcg(head); + memcg = folio_memcg(folio); /* Untracked pages have no memcg, no lruvec. Update only the node */ if (!memcg) { rcu_read_unlock(); - __mod_node_page_state(pgdat, idx, val); + mod_node_page_state(pgdat, idx, val); return; } lruvec = mem_cgroup_lruvec(memcg, pgdat); - __mod_lruvec_state(lruvec, idx, val); + mod_lruvec_state(lruvec, idx, val); rcu_read_unlock(); } -EXPORT_SYMBOL(__mod_lruvec_page_state); +EXPORT_SYMBOL(lruvec_stat_mod_folio); -void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val) +void mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val) { pg_data_t *pgdat = page_pgdat(virt_to_page(p)); struct mem_cgroup *memcg; @@ -863,117 +815,62 @@ void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val) * vmstats to keep it correct for the root memcg. */ if (!memcg) { - __mod_node_page_state(pgdat, idx, val); + mod_node_page_state(pgdat, idx, val); } else { lruvec = mem_cgroup_lruvec(memcg, pgdat); - __mod_lruvec_state(lruvec, idx, val); + mod_lruvec_state(lruvec, idx, val); } rcu_read_unlock(); } /** - * __count_memcg_events - account VM events in a cgroup + * count_memcg_events - account VM events in a cgroup * @memcg: the memory cgroup * @idx: the event item * @count: the number of events that occurred */ -void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, +void count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx, unsigned long count) { - int index = memcg_events_index(idx); + int i = memcg_events_index(idx); + int cpu; - if (mem_cgroup_disabled() || index < 0) + if (mem_cgroup_disabled()) return; - memcg_stats_lock(); - __this_cpu_add(memcg->vmstats_percpu->events[index], count); - memcg_rstat_updated(memcg, count); - memcg_stats_unlock(); -} + if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx)) + return; -static unsigned long memcg_events(struct mem_cgroup *memcg, int event) -{ - int index = memcg_events_index(event); + cpu = get_cpu(); - if (index < 0) - return 0; - return READ_ONCE(memcg->vmstats->events[index]); -} + this_cpu_add(memcg->vmstats_percpu->events[i], count); + memcg_rstat_updated(memcg, count, cpu); + trace_count_memcg_events(memcg, idx, count); -static unsigned long memcg_events_local(struct mem_cgroup *memcg, int event) -{ - long x = 0; - int cpu; - int index = memcg_events_index(event); - - if (index < 0) - return 0; - - for_each_possible_cpu(cpu) - x += per_cpu(memcg->vmstats_percpu->events[index], cpu); - return x; + put_cpu(); } -static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, - int nr_pages) +unsigned long memcg_events(struct mem_cgroup *memcg, int event) { - /* pagein of a big page is an event. So, ignore page size */ - if (nr_pages > 0) - __count_memcg_events(memcg, PGPGIN, 1); - else { - __count_memcg_events(memcg, PGPGOUT, 1); - nr_pages = -nr_pages; /* for event */ - } - - __this_cpu_add(memcg->vmstats_percpu->nr_page_events, nr_pages); -} + int i = memcg_events_index(event); -static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg, - enum mem_cgroup_events_target target) -{ - unsigned long val, next; + if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, event)) + return 0; - val = __this_cpu_read(memcg->vmstats_percpu->nr_page_events); - next = __this_cpu_read(memcg->vmstats_percpu->targets[target]); - /* from time_after() in jiffies.h */ - if ((long)(next - val) < 0) { - switch (target) { - case MEM_CGROUP_TARGET_THRESH: - next = val + THRESHOLDS_EVENTS_TARGET; - break; - case MEM_CGROUP_TARGET_SOFTLIMIT: - next = val + SOFTLIMIT_EVENTS_TARGET; - break; - default: - break; - } - __this_cpu_write(memcg->vmstats_percpu->targets[target], next); - return true; - } - return false; + return READ_ONCE(memcg->vmstats->events[i]); } -/* - * Check events in order. - * - */ -static void memcg_check_events(struct mem_cgroup *memcg, int nid) +#ifdef CONFIG_MEMCG_V1 +unsigned long memcg_events_local(struct mem_cgroup *memcg, int event) { - if (IS_ENABLED(CONFIG_PREEMPT_RT)) - return; + int i = memcg_events_index(event); - /* threshold event is triggered in finer grain than soft limit */ - if (unlikely(mem_cgroup_event_ratelimit(memcg, - MEM_CGROUP_TARGET_THRESH))) { - bool do_softlimit; + if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, event)) + return 0; - do_softlimit = mem_cgroup_event_ratelimit(memcg, - MEM_CGROUP_TARGET_SOFTLIMIT); - mem_cgroup_threshold(memcg); - if (unlikely(do_softlimit)) - mem_cgroup_update_tree(memcg, nid); - } + return READ_ONCE(memcg->vmstats->events_local[i]); } +#endif struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) { @@ -1047,17 +944,43 @@ struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) } EXPORT_SYMBOL(get_mem_cgroup_from_mm); -static __always_inline bool memcg_kmem_bypass(void) +/** + * get_mem_cgroup_from_current - Obtain a reference on current task's memcg. + */ +struct mem_cgroup *get_mem_cgroup_from_current(void) { - /* Allow remote memcg charging from any context. */ - if (unlikely(active_memcg())) - return false; + struct mem_cgroup *memcg; - /* Memcg to charge can't be determined. */ - if (!in_task() || !current->mm || (current->flags & PF_KTHREAD)) - return true; + if (mem_cgroup_disabled()) + return NULL; - return false; +again: + rcu_read_lock(); + memcg = mem_cgroup_from_task(current); + if (!css_tryget(&memcg->css)) { + rcu_read_unlock(); + goto again; + } + rcu_read_unlock(); + return memcg; +} + +/** + * get_mem_cgroup_from_folio - Obtain a reference on a given folio's memcg. + * @folio: folio from which memcg should be extracted. + */ +struct mem_cgroup *get_mem_cgroup_from_folio(struct folio *folio) +{ + struct mem_cgroup *memcg = folio_memcg(folio); + + if (mem_cgroup_disabled()) + return NULL; + + rcu_read_lock(); + if (!memcg || WARN_ON_ONCE(!css_tryget(&memcg->css))) + memcg = root_mem_cgroup; + rcu_read_unlock(); + return memcg; } /** @@ -1082,9 +1005,9 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, struct mem_cgroup_reclaim_cookie *reclaim) { struct mem_cgroup_reclaim_iter *iter; - struct cgroup_subsys_state *css = NULL; - struct mem_cgroup *memcg = NULL; - struct mem_cgroup *pos = NULL; + struct cgroup_subsys_state *css; + struct mem_cgroup *pos; + struct mem_cgroup *next; if (mem_cgroup_disabled()) return NULL; @@ -1093,81 +1016,67 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, root = root_mem_cgroup; rcu_read_lock(); +restart: + next = NULL; if (reclaim) { - struct mem_cgroup_per_node *mz; + int gen; + int nid = reclaim->pgdat->node_id; - mz = root->nodeinfo[reclaim->pgdat->node_id]; - iter = &mz->iter; + iter = &root->nodeinfo[nid]->iter; + gen = atomic_read(&iter->generation); /* * On start, join the current reclaim iteration cycle. * Exit when a concurrent walker completes it. */ if (!prev) - reclaim->generation = iter->generation; - else if (reclaim->generation != iter->generation) + reclaim->generation = gen; + else if (reclaim->generation != gen) goto out_unlock; - while (1) { - pos = READ_ONCE(iter->position); - if (!pos || css_tryget(&pos->css)) - break; - /* - * css reference reached zero, so iter->position will - * be cleared by ->css_released. However, we should not - * rely on this happening soon, because ->css_released - * is called from a work queue, and by busy-waiting we - * might block it. So we clear iter->position right - * away. - */ - (void)cmpxchg(&iter->position, pos, NULL); - } - } else if (prev) { + pos = READ_ONCE(iter->position); + } else pos = prev; - } - if (pos) - css = &pos->css; - - for (;;) { - css = css_next_descendant_pre(css, &root->css); - if (!css) { - /* - * Reclaimers share the hierarchy walk, and a - * new one might jump in right at the end of - * the hierarchy - make sure they see at least - * one group and restart from the beginning. - */ - if (!prev) - continue; - break; - } + css = pos ? &pos->css : NULL; + while ((css = css_next_descendant_pre(css, &root->css))) { /* * Verify the css and acquire a reference. The root * is provided by the caller, so we know it's alive * and kicking, and don't take an extra reference. */ - if (css == &root->css || css_tryget(css)) { - memcg = mem_cgroup_from_css(css); + if (css == &root->css || css_tryget(css)) break; - } } + next = mem_cgroup_from_css(css); + if (reclaim) { /* * The position could have already been updated by a competing * thread, so check that the value hasn't changed since we read * it to avoid reclaiming from the same cgroup twice. */ - (void)cmpxchg(&iter->position, pos, memcg); + if (cmpxchg(&iter->position, pos, next) != pos) { + if (css && css != &root->css) + css_put(css); + goto restart; + } - if (pos) - css_put(&pos->css); + if (!next) { + atomic_inc(&iter->generation); - if (!memcg) - iter->generation++; + /* + * Reclaimers share the hierarchy walk, and a + * new one might jump in right at the end of + * the hierarchy - make sure they see at least + * one group and restart from the beginning. + */ + if (!prev) + goto restart; + } } out_unlock: @@ -1175,7 +1084,7 @@ out_unlock: if (prev && prev != root) css_put(&prev->css); - return memcg; + return next; } /** @@ -1235,13 +1144,13 @@ static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg) * * This function iterates over tasks attached to @memcg or to any of its * descendants and calls @fn for each task. If @fn returns a non-zero - * value, the function breaks the iteration loop and returns the value. - * Otherwise, it will iterate over all tasks and return 0. + * value, the function breaks the iteration loop. Otherwise, it will iterate + * over all tasks and return 0. * * This function must not be called for the root memory cgroup. */ -int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, - int (*fn)(struct task_struct *, void *), void *arg) +void mem_cgroup_scan_tasks(struct mem_cgroup *memcg, + int (*fn)(struct task_struct *, void *), void *arg) { struct mem_cgroup *iter; int ret = 0; @@ -1253,15 +1162,17 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, struct task_struct *task; css_task_iter_start(&iter->css, CSS_TASK_ITER_PROCS, &it); - while (!ret && (task = css_task_iter_next(&it))) + while (!ret && (task = css_task_iter_next(&it))) { ret = fn(task, arg); + /* Avoid potential softlockup warning */ + cond_resched(); + } css_task_iter_end(&it); if (ret) { mem_cgroup_iter_break(memcg, iter); break; } } - return ret; } #ifdef CONFIG_DEBUG_VM @@ -1288,7 +1199,6 @@ void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio) * These functions are safe to use under any of the following conditions: * - folio locked * - folio_test_lru false - * - folio_memcg_lock() * - folio frozen (refcount of 0) * * Return: The lruvec this folio is on with its lock held. @@ -1310,7 +1220,6 @@ struct lruvec *folio_lruvec_lock(struct folio *folio) * These functions are safe to use under any of the following conditions: * - folio locked * - folio_test_lru false - * - folio_memcg_lock() * - folio frozen (refcount of 0) * * Return: The lruvec this folio is on with its lock held and interrupts @@ -1334,7 +1243,6 @@ struct lruvec *folio_lruvec_lock_irq(struct folio *folio) * These functions are safe to use under any of the following conditions: * - folio locked * - folio_test_lru false - * - folio_memcg_lock() * - folio frozen (refcount of 0) * * Return: The lruvec this folio is on with its lock held and interrupts @@ -1419,51 +1327,6 @@ static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg) return margin; } -/* - * A routine for checking "mem" is under move_account() or not. - * - * Checking a cgroup is mc.from or mc.to or under hierarchy of - * moving cgroups. This is for waiting at high-memory pressure - * caused by "move". - */ -static bool mem_cgroup_under_move(struct mem_cgroup *memcg) -{ - struct mem_cgroup *from; - struct mem_cgroup *to; - bool ret = false; - /* - * Unlike task_move routines, we access mc.to, mc.from not under - * mutual exclusion by cgroup_mutex. Here, we take spinlock instead. - */ - spin_lock(&mc.lock); - from = mc.from; - to = mc.to; - if (!from) - goto unlock; - - ret = mem_cgroup_is_descendant(from, memcg) || - mem_cgroup_is_descendant(to, memcg); -unlock: - spin_unlock(&mc.lock); - return ret; -} - -static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) -{ - if (mc.moving_task && current != mc.moving_task) { - if (mem_cgroup_under_move(memcg)) { - DEFINE_WAIT(wait); - prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE); - /* moving charge context might have finished. */ - if (mc.moving_task) - schedule(); - finish_wait(&mc.waitq, &wait); - return true; - } - } - return false; -} - struct memory_stat { const char *name; unsigned int idx; @@ -1480,7 +1343,7 @@ static const struct memory_stat memory_stats[] = { { "sock", MEMCG_SOCK }, { "vmalloc", MEMCG_VMALLOC }, { "shmem", NR_SHMEM }, -#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) +#ifdef CONFIG_ZSWAP { "zswap", MEMCG_ZSWAP_B }, { "zswapped", MEMCG_ZSWAPPED }, #endif @@ -1502,6 +1365,9 @@ static const struct memory_stat memory_stats[] = { { "unevictable", NR_UNEVICTABLE }, { "slab_reclaimable", NR_SLAB_RECLAIMABLE_B }, { "slab_unreclaimable", NR_SLAB_UNRECLAIMABLE_B }, +#ifdef CONFIG_HUGETLB_PAGE + { "hugetlb", NR_HUGETLB }, +#endif /* The memory events */ { "workingset_refault_anon", WORKINGSET_REFAULT_ANON }, @@ -1511,9 +1377,17 @@ static const struct memory_stat memory_stats[] = { { "workingset_restore_anon", WORKINGSET_RESTORE_ANON }, { "workingset_restore_file", WORKINGSET_RESTORE_FILE }, { "workingset_nodereclaim", WORKINGSET_NODERECLAIM }, + + { "pgdemote_kswapd", PGDEMOTE_KSWAPD }, + { "pgdemote_direct", PGDEMOTE_DIRECT }, + { "pgdemote_khugepaged", PGDEMOTE_KHUGEPAGED }, + { "pgdemote_proactive", PGDEMOTE_PROACTIVE }, +#ifdef CONFIG_NUMA_BALANCING + { "pgpromote_success", PGPROMOTE_SUCCESS }, +#endif }; -/* Translate stat items to the correct unit for memory.stat output */ +/* The actual unit of the state item, not the same as the output unit */ static int memcg_page_state_unit(int item) { switch (item) { @@ -1521,6 +1395,25 @@ static int memcg_page_state_unit(int item) case MEMCG_ZSWAP_B: case NR_SLAB_RECLAIMABLE_B: case NR_SLAB_UNRECLAIMABLE_B: + return 1; + case NR_KERNEL_STACK_KB: + return SZ_1K; + default: + return PAGE_SIZE; + } +} + +/* Translate stat items to the correct unit for memory.stat output */ +static int memcg_page_state_output_unit(int item) +{ + /* + * Workingset state is actually in pages, but we export it to userspace + * as a scalar count of events, so special case it here. + * + * Demotion and promotion activities are exported in pages, consistent + * with their global counterparts. + */ + switch (item) { case WORKINGSET_REFAULT_ANON: case WORKINGSET_REFAULT_FILE: case WORKINGSET_ACTIVATE_ANON: @@ -1528,26 +1421,48 @@ static int memcg_page_state_unit(int item) case WORKINGSET_RESTORE_ANON: case WORKINGSET_RESTORE_FILE: case WORKINGSET_NODERECLAIM: + case PGDEMOTE_KSWAPD: + case PGDEMOTE_DIRECT: + case PGDEMOTE_KHUGEPAGED: + case PGDEMOTE_PROACTIVE: +#ifdef CONFIG_NUMA_BALANCING + case PGPROMOTE_SUCCESS: +#endif return 1; - case NR_KERNEL_STACK_KB: - return SZ_1K; default: - return PAGE_SIZE; + return memcg_page_state_unit(item); } } -static inline unsigned long memcg_page_state_output(struct mem_cgroup *memcg, - int item) +unsigned long memcg_page_state_output(struct mem_cgroup *memcg, int item) { - return memcg_page_state(memcg, item) * memcg_page_state_unit(item); + return memcg_page_state(memcg, item) * + memcg_page_state_output_unit(item); } -static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bufsize) +#ifdef CONFIG_MEMCG_V1 +unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item) { - struct seq_buf s; - int i; + return memcg_page_state_local(memcg, item) * + memcg_page_state_output_unit(item); +} +#endif - seq_buf_init(&s, buf, bufsize); +#ifdef CONFIG_HUGETLB_PAGE +static bool memcg_accounts_hugetlb(void) +{ + return cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_HUGETLB_ACCOUNTING; +} +#else /* CONFIG_HUGETLB_PAGE */ +static bool memcg_accounts_hugetlb(void) +{ + return false; +} +#endif /* CONFIG_HUGETLB_PAGE */ + +static void memcg_stat_format(struct mem_cgroup *memcg, struct seq_buf *s) +{ + int i; /* * Provide statistics on the state of the memory subsystem as @@ -1559,46 +1474,60 @@ static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bufsize) * * Current memory state: */ - mem_cgroup_flush_stats(); + mem_cgroup_flush_stats(memcg); for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { u64 size; +#ifdef CONFIG_HUGETLB_PAGE + if (unlikely(memory_stats[i].idx == NR_HUGETLB) && + !memcg_accounts_hugetlb()) + continue; +#endif size = memcg_page_state_output(memcg, memory_stats[i].idx); - seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size); + seq_buf_printf(s, "%s %llu\n", memory_stats[i].name, size); if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) { size += memcg_page_state_output(memcg, NR_SLAB_RECLAIMABLE_B); - seq_buf_printf(&s, "slab %llu\n", size); + seq_buf_printf(s, "slab %llu\n", size); } } /* Accumulated memory events */ - seq_buf_printf(&s, "pgscan %lu\n", + seq_buf_printf(s, "pgscan %lu\n", memcg_events(memcg, PGSCAN_KSWAPD) + memcg_events(memcg, PGSCAN_DIRECT) + + memcg_events(memcg, PGSCAN_PROACTIVE) + memcg_events(memcg, PGSCAN_KHUGEPAGED)); - seq_buf_printf(&s, "pgsteal %lu\n", + seq_buf_printf(s, "pgsteal %lu\n", memcg_events(memcg, PGSTEAL_KSWAPD) + memcg_events(memcg, PGSTEAL_DIRECT) + + memcg_events(memcg, PGSTEAL_PROACTIVE) + memcg_events(memcg, PGSTEAL_KHUGEPAGED)); for (i = 0; i < ARRAY_SIZE(memcg_vm_event_stat); i++) { +#ifdef CONFIG_MEMCG_V1 if (memcg_vm_event_stat[i] == PGPGIN || memcg_vm_event_stat[i] == PGPGOUT) continue; - - seq_buf_printf(&s, "%s %lu\n", +#endif + seq_buf_printf(s, "%s %lu\n", vm_event_name(memcg_vm_event_stat[i]), memcg_events(memcg, memcg_vm_event_stat[i])); } +} - /* The above should easily fit into one page */ - WARN_ON_ONCE(seq_buf_has_overflowed(&s)); +static void memory_stat_format(struct mem_cgroup *memcg, struct seq_buf *s) +{ + if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) + memcg_stat_format(memcg, s); + else + memcg1_stat_format(memcg, s); + if (seq_buf_has_overflowed(s)) + pr_warn("%s: Warning, stat buffer overflow, please report\n", __func__); } -#define K(x) ((x) << (PAGE_SHIFT-10)) /** * mem_cgroup_print_oom_context: Print OOM information relevant to * memory controller. @@ -1632,17 +1561,26 @@ void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct * void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg) { /* Use static buffer, for the caller is holding oom_lock. */ - static char buf[PAGE_SIZE]; + static char buf[SEQ_BUF_SIZE]; + struct seq_buf s; + unsigned long memory_failcnt; lockdep_assert_held(&oom_lock); + if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) + memory_failcnt = atomic_long_read(&memcg->memory_events[MEMCG_MAX]); + else + memory_failcnt = memcg->memory.failcnt; + pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n", K((u64)page_counter_read(&memcg->memory)), - K((u64)READ_ONCE(memcg->memory.max)), memcg->memory.failcnt); + K((u64)READ_ONCE(memcg->memory.max)), memory_failcnt); if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n", K((u64)page_counter_read(&memcg->swap)), - K((u64)READ_ONCE(memcg->swap.max)), memcg->swap.failcnt); + K((u64)READ_ONCE(memcg->swap.max)), + atomic_long_read(&memcg->memory_events[MEMCG_SWAP_MAX])); +#ifdef CONFIG_MEMCG_V1 else { pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n", K((u64)page_counter_read(&memcg->memsw)), @@ -1651,12 +1589,14 @@ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg) K((u64)page_counter_read(&memcg->kmem)), K((u64)memcg->kmem.max), memcg->kmem.failcnt); } +#endif pr_info("Memory cgroup stats for "); pr_cont_cgroup_path(memcg->css.cgroup); pr_cont(":"); - memory_stat_format(memcg, buf, sizeof(buf)); - pr_info("%s", buf); + seq_buf_init(&s, buf, SEQ_BUF_SIZE); + memory_stat_format(memcg, &s); + seq_buf_do_printk(&s, KERN_INFO); } /* @@ -1686,6 +1626,37 @@ unsigned long mem_cgroup_size(struct mem_cgroup *memcg) return page_counter_read(&memcg->memory); } +void __memcg_memory_event(struct mem_cgroup *memcg, + enum memcg_memory_event event, bool allow_spinning) +{ + bool swap_event = event == MEMCG_SWAP_HIGH || event == MEMCG_SWAP_MAX || + event == MEMCG_SWAP_FAIL; + + /* For now only MEMCG_MAX can happen with !allow_spinning context. */ + VM_WARN_ON_ONCE(!allow_spinning && event != MEMCG_MAX); + + atomic_long_inc(&memcg->memory_events_local[event]); + if (!swap_event && allow_spinning) + cgroup_file_notify(&memcg->events_local_file); + + do { + atomic_long_inc(&memcg->memory_events[event]); + if (allow_spinning) { + if (swap_event) + cgroup_file_notify(&memcg->swap_events_file); + else + cgroup_file_notify(&memcg->events_file); + } + + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) + break; + if (cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_LOCAL_EVENTS) + break; + } while ((memcg = parent_mem_cgroup(memcg)) && + !mem_cgroup_is_root(memcg)); +} +EXPORT_SYMBOL_GPL(__memcg_memory_event); + static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, int order) { @@ -1708,187 +1679,13 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask, * A few threads which were not waiting at mutex_lock_killable() can * fail to bail out. Therefore, check again after holding oom_lock. */ - ret = task_is_dying() || out_of_memory(&oc); + ret = out_of_memory(&oc); unlock: mutex_unlock(&oom_lock); return ret; } -static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg, - pg_data_t *pgdat, - gfp_t gfp_mask, - unsigned long *total_scanned) -{ - struct mem_cgroup *victim = NULL; - int total = 0; - int loop = 0; - unsigned long excess; - unsigned long nr_scanned; - struct mem_cgroup_reclaim_cookie reclaim = { - .pgdat = pgdat, - }; - - excess = soft_limit_excess(root_memcg); - - while (1) { - victim = mem_cgroup_iter(root_memcg, victim, &reclaim); - if (!victim) { - loop++; - if (loop >= 2) { - /* - * If we have not been able to reclaim - * anything, it might because there are - * no reclaimable pages under this hierarchy - */ - if (!total) - break; - /* - * We want to do more targeted reclaim. - * excess >> 2 is not to excessive so as to - * reclaim too much, nor too less that we keep - * coming back to reclaim from this cgroup - */ - if (total >= (excess >> 2) || - (loop > MEM_CGROUP_MAX_RECLAIM_LOOPS)) - break; - } - continue; - } - total += mem_cgroup_shrink_node(victim, gfp_mask, false, - pgdat, &nr_scanned); - *total_scanned += nr_scanned; - if (!soft_limit_excess(root_memcg)) - break; - } - mem_cgroup_iter_break(root_memcg, victim); - return total; -} - -#ifdef CONFIG_LOCKDEP -static struct lockdep_map memcg_oom_lock_dep_map = { - .name = "memcg_oom_lock", -}; -#endif - -static DEFINE_SPINLOCK(memcg_oom_lock); - -/* - * Check OOM-Killer is already running under our hierarchy. - * If someone is running, return false. - */ -static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg) -{ - struct mem_cgroup *iter, *failed = NULL; - - spin_lock(&memcg_oom_lock); - - for_each_mem_cgroup_tree(iter, memcg) { - if (iter->oom_lock) { - /* - * this subtree of our hierarchy is already locked - * so we cannot give a lock. - */ - failed = iter; - mem_cgroup_iter_break(memcg, iter); - break; - } else - iter->oom_lock = true; - } - - if (failed) { - /* - * OK, we failed to lock the whole subtree so we have - * to clean up what we set up to the failing subtree - */ - for_each_mem_cgroup_tree(iter, memcg) { - if (iter == failed) { - mem_cgroup_iter_break(memcg, iter); - break; - } - iter->oom_lock = false; - } - } else - mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_); - - spin_unlock(&memcg_oom_lock); - - return !failed; -} - -static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg) -{ - struct mem_cgroup *iter; - - spin_lock(&memcg_oom_lock); - mutex_release(&memcg_oom_lock_dep_map, _RET_IP_); - for_each_mem_cgroup_tree(iter, memcg) - iter->oom_lock = false; - spin_unlock(&memcg_oom_lock); -} - -static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg) -{ - struct mem_cgroup *iter; - - spin_lock(&memcg_oom_lock); - for_each_mem_cgroup_tree(iter, memcg) - iter->under_oom++; - spin_unlock(&memcg_oom_lock); -} - -static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg) -{ - struct mem_cgroup *iter; - - /* - * Be careful about under_oom underflows because a child memcg - * could have been added after mem_cgroup_mark_under_oom. - */ - spin_lock(&memcg_oom_lock); - for_each_mem_cgroup_tree(iter, memcg) - if (iter->under_oom > 0) - iter->under_oom--; - spin_unlock(&memcg_oom_lock); -} - -static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq); - -struct oom_wait_info { - struct mem_cgroup *memcg; - wait_queue_entry_t wait; -}; - -static int memcg_oom_wake_function(wait_queue_entry_t *wait, - unsigned mode, int sync, void *arg) -{ - struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg; - struct mem_cgroup *oom_wait_memcg; - struct oom_wait_info *oom_wait_info; - - oom_wait_info = container_of(wait, struct oom_wait_info, wait); - oom_wait_memcg = oom_wait_info->memcg; - - if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) && - !mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg)) - return 0; - return autoremove_wake_function(wait, mode, sync, arg); -} - -static void memcg_oom_recover(struct mem_cgroup *memcg) -{ - /* - * For the following lockless ->under_oom test, the only required - * guarantee is that it must see the state asserted by an OOM when - * this function is called as a result of userland actions - * triggered by the notification of the OOM. This is trivially - * achieved by invoking mem_cgroup_mark_under_oom() before - * triggering notification. - */ - if (memcg && memcg->under_oom) - __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); -} - /* * Returns true if successfully killed one or more processes. Though in some * corner cases it can return true even without killing any process. @@ -1902,121 +1699,17 @@ static bool mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) memcg_memory_event(memcg, MEMCG_OOM); - /* - * We are in the middle of the charge context here, so we - * don't want to block when potentially sitting on a callstack - * that holds all kinds of filesystem and mm locks. - * - * cgroup1 allows disabling the OOM killer and waiting for outside - * handling until the charge can succeed; remember the context and put - * the task to sleep at the end of the page fault when all locks are - * released. - * - * On the other hand, in-kernel OOM killer allows for an async victim - * memory reclaim (oom_reaper) and that means that we are not solely - * relying on the oom victim to make a forward progress and we can - * invoke the oom killer here. - * - * Please note that mem_cgroup_out_of_memory might fail to find a - * victim and then we have to bail out from the charge path. - */ - if (memcg->oom_kill_disable) { - if (current->in_user_fault) { - css_get(&memcg->css); - current->memcg_in_oom = memcg; - current->memcg_oom_gfp_mask = mask; - current->memcg_oom_order = order; - } + if (!memcg1_oom_prepare(memcg, &locked)) return false; - } - - mem_cgroup_mark_under_oom(memcg); - - locked = mem_cgroup_oom_trylock(memcg); - if (locked) - mem_cgroup_oom_notify(memcg); - - mem_cgroup_unmark_under_oom(memcg); ret = mem_cgroup_out_of_memory(memcg, mask, order); - if (locked) - mem_cgroup_oom_unlock(memcg); + memcg1_oom_finish(memcg, locked); return ret; } /** - * mem_cgroup_oom_synchronize - complete memcg OOM handling - * @handle: actually kill/wait or just clean up the OOM state - * - * This has to be called at the end of a page fault if the memcg OOM - * handler was enabled. - * - * Memcg supports userspace OOM handling where failed allocations must - * sleep on a waitqueue until the userspace task resolves the - * situation. Sleeping directly in the charge context with all kinds - * of locks held is not a good idea, instead we remember an OOM state - * in the task and mem_cgroup_oom_synchronize() has to be called at - * the end of the page fault to complete the OOM handling. - * - * Returns %true if an ongoing memcg OOM situation was detected and - * completed, %false otherwise. - */ -bool mem_cgroup_oom_synchronize(bool handle) -{ - struct mem_cgroup *memcg = current->memcg_in_oom; - struct oom_wait_info owait; - bool locked; - - /* OOM is global, do not handle */ - if (!memcg) - return false; - - if (!handle) - goto cleanup; - - owait.memcg = memcg; - owait.wait.flags = 0; - owait.wait.func = memcg_oom_wake_function; - owait.wait.private = current; - INIT_LIST_HEAD(&owait.wait.entry); - - prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE); - mem_cgroup_mark_under_oom(memcg); - - locked = mem_cgroup_oom_trylock(memcg); - - if (locked) - mem_cgroup_oom_notify(memcg); - - if (locked && !memcg->oom_kill_disable) { - mem_cgroup_unmark_under_oom(memcg); - finish_wait(&memcg_oom_waitq, &owait.wait); - mem_cgroup_out_of_memory(memcg, current->memcg_oom_gfp_mask, - current->memcg_oom_order); - } else { - schedule(); - mem_cgroup_unmark_under_oom(memcg); - finish_wait(&memcg_oom_waitq, &owait.wait); - } - - if (locked) { - mem_cgroup_oom_unlock(memcg); - /* - * There is no guarantee that an OOM-lock contender - * sees the wakeups triggered by the OOM kill - * uncharges. Wake any sleepers explicitly. - */ - memcg_oom_recover(memcg); - } -cleanup: - current->memcg_in_oom = NULL; - css_put(&memcg->css); - return true; -} - -/** * mem_cgroup_get_oom_group - get a memory cgroup to clean up after OOM * @victim: task to be killed by the OOM killer * @oom_domain: memcg in case of memcg OOM, NULL in case of system-wide OOM @@ -2058,7 +1751,7 @@ struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim, * highest-level memory cgroup with oom.group set. */ for (; memcg; memcg = parent_mem_cgroup(memcg)) { - if (memcg->oom_group) + if (READ_ONCE(memcg->oom_group)) oom_group = memcg; if (memcg == oom_domain) @@ -2080,251 +1773,241 @@ void mem_cgroup_print_oom_group(struct mem_cgroup *memcg) pr_cont(" are going to be killed due to memory.oom.group set\n"); } -/** - * folio_memcg_lock - Bind a folio to its memcg. - * @folio: The folio. - * - * This function prevents unlocked LRU folios from being moved to - * another cgroup. - * - * It ensures lifetime of the bound memcg. The caller is responsible - * for the lifetime of the folio. - */ -void folio_memcg_lock(struct folio *folio) -{ - struct mem_cgroup *memcg; - unsigned long flags; - - /* - * The RCU lock is held throughout the transaction. The fast - * path can get away without acquiring the memcg->move_lock - * because page moving starts with an RCU grace period. - */ - rcu_read_lock(); - - if (mem_cgroup_disabled()) - return; -again: - memcg = folio_memcg(folio); - if (unlikely(!memcg)) - return; - -#ifdef CONFIG_PROVE_LOCKING - local_irq_save(flags); - might_lock(&memcg->move_lock); - local_irq_restore(flags); -#endif - - if (atomic_read(&memcg->moving_account) <= 0) - return; - - spin_lock_irqsave(&memcg->move_lock, flags); - if (memcg != folio_memcg(folio)) { - spin_unlock_irqrestore(&memcg->move_lock, flags); - goto again; - } - - /* - * When charge migration first begins, we can have multiple - * critical sections holding the fast-path RCU lock and one - * holding the slowpath move_lock. Track the task who has the - * move_lock for unlock_page_memcg(). - */ - memcg->move_lock_task = current; - memcg->move_lock_flags = flags; -} - -void lock_page_memcg(struct page *page) -{ - folio_memcg_lock(page_folio(page)); -} - -static void __folio_memcg_unlock(struct mem_cgroup *memcg) -{ - if (memcg && memcg->move_lock_task == current) { - unsigned long flags = memcg->move_lock_flags; - - memcg->move_lock_task = NULL; - memcg->move_lock_flags = 0; - - spin_unlock_irqrestore(&memcg->move_lock, flags); - } - - rcu_read_unlock(); -} - -/** - * folio_memcg_unlock - Release the binding between a folio and its memcg. - * @folio: The folio. - * - * This releases the binding created by folio_memcg_lock(). This does - * not change the accounting of this folio to its memcg, but it does - * permit others to change it. +/* + * The value of NR_MEMCG_STOCK is selected to keep the cached memcgs and their + * nr_pages in a single cacheline. This may change in future. */ -void folio_memcg_unlock(struct folio *folio) -{ - __folio_memcg_unlock(folio_memcg(folio)); -} +#define NR_MEMCG_STOCK 7 +#define FLUSHING_CACHED_CHARGE 0 +struct memcg_stock_pcp { + local_trylock_t lock; + uint8_t nr_pages[NR_MEMCG_STOCK]; + struct mem_cgroup *cached[NR_MEMCG_STOCK]; -void unlock_page_memcg(struct page *page) -{ - folio_memcg_unlock(page_folio(page)); -} + struct work_struct work; + unsigned long flags; +}; -struct memcg_stock_pcp { - local_lock_t stock_lock; - struct mem_cgroup *cached; /* this never be root cgroup */ - unsigned int nr_pages; +static DEFINE_PER_CPU_ALIGNED(struct memcg_stock_pcp, memcg_stock) = { + .lock = INIT_LOCAL_TRYLOCK(lock), +}; -#ifdef CONFIG_MEMCG_KMEM +struct obj_stock_pcp { + local_trylock_t lock; + unsigned int nr_bytes; struct obj_cgroup *cached_objcg; struct pglist_data *cached_pgdat; - unsigned int nr_bytes; int nr_slab_reclaimable_b; int nr_slab_unreclaimable_b; -#endif struct work_struct work; unsigned long flags; -#define FLUSHING_CACHED_CHARGE 0 }; -static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock) = { - .stock_lock = INIT_LOCAL_LOCK(stock_lock), + +static DEFINE_PER_CPU_ALIGNED(struct obj_stock_pcp, obj_stock) = { + .lock = INIT_LOCAL_TRYLOCK(lock), }; + static DEFINE_MUTEX(percpu_charge_mutex); -#ifdef CONFIG_MEMCG_KMEM -static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock); -static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, +static void drain_obj_stock(struct obj_stock_pcp *stock); +static bool obj_stock_flush_required(struct obj_stock_pcp *stock, struct mem_cgroup *root_memcg); -static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages); - -#else -static inline struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock) -{ - return NULL; -} -static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, - struct mem_cgroup *root_memcg) -{ - return false; -} -static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages) -{ -} -#endif /** * consume_stock: Try to consume stocked charge on this cpu. * @memcg: memcg to consume from. * @nr_pages: how many pages to charge. * - * The charges will only happen if @memcg matches the current cpu's memcg - * stock, and at least @nr_pages are available in that stock. Failure to - * service an allocation will refill the stock. + * Consume the cached charge if enough nr_pages are present otherwise return + * failure. Also return failure for charge request larger than + * MEMCG_CHARGE_BATCH or if the local lock is already taken. * * returns true if successful, false otherwise. */ static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) { struct memcg_stock_pcp *stock; - unsigned long flags; + uint8_t stock_pages; bool ret = false; + int i; - if (nr_pages > MEMCG_CHARGE_BATCH) + if (nr_pages > MEMCG_CHARGE_BATCH || + !local_trylock(&memcg_stock.lock)) return ret; - local_lock_irqsave(&memcg_stock.stock_lock, flags); - stock = this_cpu_ptr(&memcg_stock); - if (memcg == stock->cached && stock->nr_pages >= nr_pages) { - stock->nr_pages -= nr_pages; - ret = true; + + for (i = 0; i < NR_MEMCG_STOCK; ++i) { + if (memcg != READ_ONCE(stock->cached[i])) + continue; + + stock_pages = READ_ONCE(stock->nr_pages[i]); + if (stock_pages >= nr_pages) { + WRITE_ONCE(stock->nr_pages[i], stock_pages - nr_pages); + ret = true; + } + break; } - local_unlock_irqrestore(&memcg_stock.stock_lock, flags); + local_unlock(&memcg_stock.lock); return ret; } +static void memcg_uncharge(struct mem_cgroup *memcg, unsigned int nr_pages) +{ + page_counter_uncharge(&memcg->memory, nr_pages); + if (do_memsw_account()) + page_counter_uncharge(&memcg->memsw, nr_pages); +} + /* * Returns stocks cached in percpu and reset cached information. */ -static void drain_stock(struct memcg_stock_pcp *stock) +static void drain_stock(struct memcg_stock_pcp *stock, int i) { - struct mem_cgroup *old = stock->cached; + struct mem_cgroup *old = READ_ONCE(stock->cached[i]); + uint8_t stock_pages; if (!old) return; - if (stock->nr_pages) { - page_counter_uncharge(&old->memory, stock->nr_pages); - if (do_memsw_account()) - page_counter_uncharge(&old->memsw, stock->nr_pages); - stock->nr_pages = 0; + stock_pages = READ_ONCE(stock->nr_pages[i]); + if (stock_pages) { + memcg_uncharge(old, stock_pages); + WRITE_ONCE(stock->nr_pages[i], 0); } css_put(&old->css); - stock->cached = NULL; + WRITE_ONCE(stock->cached[i], NULL); +} + +static void drain_stock_fully(struct memcg_stock_pcp *stock) +{ + int i; + + for (i = 0; i < NR_MEMCG_STOCK; ++i) + drain_stock(stock, i); } -static void drain_local_stock(struct work_struct *dummy) +static void drain_local_memcg_stock(struct work_struct *dummy) { struct memcg_stock_pcp *stock; - struct obj_cgroup *old = NULL; - unsigned long flags; - /* - * The only protection from cpu hotplug (memcg_hotplug_cpu_dead) vs. - * drain_stock races is that we always operate on local CPU stock - * here with IRQ disabled - */ - local_lock_irqsave(&memcg_stock.stock_lock, flags); + if (WARN_ONCE(!in_task(), "drain in non-task context")) + return; + + local_lock(&memcg_stock.lock); stock = this_cpu_ptr(&memcg_stock); - old = drain_obj_stock(stock); - drain_stock(stock); + drain_stock_fully(stock); clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); - local_unlock_irqrestore(&memcg_stock.stock_lock, flags); - if (old) - obj_cgroup_put(old); + local_unlock(&memcg_stock.lock); } -/* - * Cache charges(val) to local per_cpu area. - * This will be consumed by consume_stock() function, later. - */ -static void __refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) +static void drain_local_obj_stock(struct work_struct *dummy) +{ + struct obj_stock_pcp *stock; + + if (WARN_ONCE(!in_task(), "drain in non-task context")) + return; + + local_lock(&obj_stock.lock); + + stock = this_cpu_ptr(&obj_stock); + drain_obj_stock(stock); + clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); + + local_unlock(&obj_stock.lock); +} + +static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) { struct memcg_stock_pcp *stock; + struct mem_cgroup *cached; + uint8_t stock_pages; + bool success = false; + int empty_slot = -1; + int i; + + /* + * For now limit MEMCG_CHARGE_BATCH to 127 and less. In future if we + * decide to increase it more than 127 then we will need more careful + * handling of nr_pages[] in struct memcg_stock_pcp. + */ + BUILD_BUG_ON(MEMCG_CHARGE_BATCH > S8_MAX); + + VM_WARN_ON_ONCE(mem_cgroup_is_root(memcg)); + + if (nr_pages > MEMCG_CHARGE_BATCH || + !local_trylock(&memcg_stock.lock)) { + /* + * In case of larger than batch refill or unlikely failure to + * lock the percpu memcg_stock.lock, uncharge memcg directly. + */ + memcg_uncharge(memcg, nr_pages); + return; + } stock = this_cpu_ptr(&memcg_stock); - if (stock->cached != memcg) { /* reset if necessary */ - drain_stock(stock); + for (i = 0; i < NR_MEMCG_STOCK; ++i) { + cached = READ_ONCE(stock->cached[i]); + if (!cached && empty_slot == -1) + empty_slot = i; + if (memcg == READ_ONCE(stock->cached[i])) { + stock_pages = READ_ONCE(stock->nr_pages[i]) + nr_pages; + WRITE_ONCE(stock->nr_pages[i], stock_pages); + if (stock_pages > MEMCG_CHARGE_BATCH) + drain_stock(stock, i); + success = true; + break; + } + } + + if (!success) { + i = empty_slot; + if (i == -1) { + i = get_random_u32_below(NR_MEMCG_STOCK); + drain_stock(stock, i); + } css_get(&memcg->css); - stock->cached = memcg; + WRITE_ONCE(stock->cached[i], memcg); + WRITE_ONCE(stock->nr_pages[i], nr_pages); } - stock->nr_pages += nr_pages; - if (stock->nr_pages > MEMCG_CHARGE_BATCH) - drain_stock(stock); + local_unlock(&memcg_stock.lock); } -static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) +static bool is_memcg_drain_needed(struct memcg_stock_pcp *stock, + struct mem_cgroup *root_memcg) { - unsigned long flags; + struct mem_cgroup *memcg; + bool flush = false; + int i; - local_lock_irqsave(&memcg_stock.stock_lock, flags); - __refill_stock(memcg, nr_pages); - local_unlock_irqrestore(&memcg_stock.stock_lock, flags); + rcu_read_lock(); + for (i = 0; i < NR_MEMCG_STOCK; ++i) { + memcg = READ_ONCE(stock->cached[i]); + if (!memcg) + continue; + + if (READ_ONCE(stock->nr_pages[i]) && + mem_cgroup_is_descendant(memcg, root_memcg)) { + flush = true; + break; + } + } + rcu_read_unlock(); + return flush; } /* * Drains all per-CPU charge caches for given root_memcg resp. subtree * of the hierarchy under it. */ -static void drain_all_stock(struct mem_cgroup *root_memcg) +void drain_all_stock(struct mem_cgroup *root_memcg) { int cpu, curcpu; @@ -2340,25 +2023,27 @@ static void drain_all_stock(struct mem_cgroup *root_memcg) migrate_disable(); curcpu = smp_processor_id(); for_each_online_cpu(cpu) { - struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); - struct mem_cgroup *memcg; - bool flush = false; + struct memcg_stock_pcp *memcg_st = &per_cpu(memcg_stock, cpu); + struct obj_stock_pcp *obj_st = &per_cpu(obj_stock, cpu); - rcu_read_lock(); - memcg = stock->cached; - if (memcg && stock->nr_pages && - mem_cgroup_is_descendant(memcg, root_memcg)) - flush = true; - else if (obj_stock_flush_required(stock, root_memcg)) - flush = true; - rcu_read_unlock(); + if (!test_bit(FLUSHING_CACHED_CHARGE, &memcg_st->flags) && + is_memcg_drain_needed(memcg_st, root_memcg) && + !test_and_set_bit(FLUSHING_CACHED_CHARGE, + &memcg_st->flags)) { + if (cpu == curcpu) + drain_local_memcg_stock(&memcg_st->work); + else if (!cpu_is_isolated(cpu)) + schedule_work_on(cpu, &memcg_st->work); + } - if (flush && - !test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) { + if (!test_bit(FLUSHING_CACHED_CHARGE, &obj_st->flags) && + obj_stock_flush_required(obj_st, root_memcg) && + !test_and_set_bit(FLUSHING_CACHED_CHARGE, + &obj_st->flags)) { if (cpu == curcpu) - drain_local_stock(&stock->work); - else - schedule_work_on(cpu, &stock->work); + drain_local_obj_stock(&obj_st->work); + else if (!cpu_is_isolated(cpu)) + schedule_work_on(cpu, &obj_st->work); } } migrate_enable(); @@ -2367,10 +2052,9 @@ static void drain_all_stock(struct mem_cgroup *root_memcg) static int memcg_hotplug_cpu_dead(unsigned int cpu) { - struct memcg_stock_pcp *stock; - - stock = &per_cpu(memcg_stock, cpu); - drain_stock(stock); + /* no need for the local lock */ + drain_obj_stock(&per_cpu(obj_stock, cpu)); + drain_stock_fully(&per_cpu(memcg_stock, cpu)); return 0; } @@ -2548,10 +2232,11 @@ static unsigned long calculate_high_delay(struct mem_cgroup *memcg, } /* - * Scheduled by try_charge() to be executed from the userland return path - * and reclaims memory over the high limit. + * Reclaims memory over the high limit. Called directly from + * try_charge() (context permitting), as well as from the userland + * return path where reclaim is always able to block. */ -void mem_cgroup_handle_over_high(void) +void __mem_cgroup_handle_over_high(gfp_t gfp_mask) { unsigned long penalty_jiffies; unsigned long pflags; @@ -2561,14 +2246,22 @@ void mem_cgroup_handle_over_high(void) struct mem_cgroup *memcg; bool in_retry = false; - if (likely(!nr_pages)) - return; - memcg = get_mem_cgroup_from_mm(current->mm); current->memcg_nr_pages_over_high = 0; retry_reclaim: /* + * Bail if the task is already exiting. Unlike memory.max, + * memory.high enforcement isn't as strict, and there is no + * OOM killer involved, which means the excess could already + * be much bigger (and still growing) than it could for + * memory.max; the dying task could get stuck in fruitless + * reclaim for a long time, which isn't desirable. + */ + if (task_is_dying()) + goto out; + + /* * The allocating task should reclaim at least the batch size, but for * subsequent retries we only want to do what's necessary to prevent oom * or breaching resource isolation. @@ -2579,7 +2272,7 @@ retry_reclaim: */ nr_reclaimed = reclaim_high(memcg, in_retry ? SWAP_CLUSTER_MAX : nr_pages, - GFP_KERNEL); + gfp_mask); /* * memory.high is breached and reclaim is unable to keep up. Throttle @@ -2618,6 +2311,9 @@ retry_reclaim: } /* + * Reclaim didn't manage to push usage below the limit, slow + * this allocating task down. + * * If we exit early, we're guaranteed to die (since * schedule_timeout_killable sets TASK_KILLABLE). This means we don't * need to account for any ill-begotten jiffies to pay them off later. @@ -2631,7 +2327,7 @@ out: } static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, - unsigned int nr_pages) + unsigned int nr_pages) { unsigned int batch = max(MEMCG_CHARGE_BATCH, nr_pages); int nr_retries = MAX_RECLAIM_RETRIES; @@ -2643,11 +2339,16 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, bool drained = false; bool raised_max_event = false; unsigned long pflags; + bool allow_spinning = gfpflags_allow_spinning(gfp_mask); retry: if (consume_stock(memcg, nr_pages)) return 0; + if (!allow_spinning) + /* Avoid the refill and flush of the older stock */ + batch = nr_pages; + if (!do_memsw_account() || page_counter_try_charge(&memcg->memsw, batch, &counter)) { if (page_counter_try_charge(&memcg->memory, batch, &counter)) @@ -2680,13 +2381,12 @@ retry: if (!gfpflags_allow_blocking(gfp_mask)) goto nomem; - memcg_memory_event(mem_over_limit, MEMCG_MAX); + __memcg_memory_event(mem_over_limit, MEMCG_MAX, allow_spinning); raised_max_event = true; psi_memstall_enter(&pflags); nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages, - gfp_mask, reclaim_options, - NULL); + gfp_mask, reclaim_options, NULL); psi_memstall_leave(&pflags); if (mem_cgroup_margin(mem_over_limit) >= nr_pages) @@ -2711,12 +2411,6 @@ retry: */ if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER)) goto retry; - /* - * At task move, charge accounts can be doubly counted. So, it's - * better to wait until the end of task_move if something is going on. - */ - if (mem_cgroup_wait_acct_move(mem_over_limit)) - goto retry; if (nr_retries--) goto retry; @@ -2754,7 +2448,7 @@ force: * a MEMCG_MAX event. */ if (!raised_max_event) - memcg_memory_event(mem_over_limit, MEMCG_MAX); + __memcg_memory_event(mem_over_limit, MEMCG_MAX, allow_spinning); /* * The allocation either can't fail or will lead to more memory @@ -2813,11 +2507,17 @@ done_restock: } } while ((memcg = parent_mem_cgroup(memcg))); + /* + * Reclaim is set up above to be called from the userland + * return path. But also attempt synchronous reclaim to avoid + * excessive overrun while the task is still inside the + * kernel. If this is successful, the return path will see it + * when it rechecks the overage and simply bail out. + */ if (current->memcg_nr_pages_over_high > MEMCG_CHARGE_BATCH && !(current->flags & PF_MEMALLOC) && - gfpflags_allow_blocking(gfp_mask)) { - mem_cgroup_handle_over_high(); - } + gfpflags_allow_blocking(gfp_mask)) + __mem_cgroup_handle_over_high(gfp_mask); return 0; } @@ -2830,160 +2530,89 @@ static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, return try_charge_memcg(memcg, gfp_mask, nr_pages); } -static inline void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) -{ - if (mem_cgroup_is_root(memcg)) - return; - - page_counter_uncharge(&memcg->memory, nr_pages); - if (do_memsw_account()) - page_counter_uncharge(&memcg->memsw, nr_pages); -} - static void commit_charge(struct folio *folio, struct mem_cgroup *memcg) { - VM_BUG_ON_FOLIO(folio_memcg(folio), folio); + VM_BUG_ON_FOLIO(folio_memcg_charged(folio), folio); /* * Any of the following ensures page's memcg stability: * * - the page lock * - LRU isolation - * - lock_page_memcg() * - exclusive reference - * - mem_cgroup_trylock_pages() */ folio->memcg_data = (unsigned long)memcg; } -#ifdef CONFIG_MEMCG_KMEM -/* - * The allocated objcg pointers array is not accounted directly. - * Moreover, it should not come from DMA buffer and is not readily - * reclaimable. So those GFP bits should be masked off. - */ -#define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT) +#ifdef CONFIG_MEMCG_NMI_SAFETY_REQUIRES_ATOMIC +static inline void account_slab_nmi_safe(struct mem_cgroup *memcg, + struct pglist_data *pgdat, + enum node_stat_item idx, int nr) +{ + struct lruvec *lruvec; -/* - * mod_objcg_mlstate() may be called with irq enabled, so - * mod_memcg_lruvec_state() should be used. - */ -static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, - struct pglist_data *pgdat, - enum node_stat_item idx, int nr) + if (likely(!in_nmi())) { + lruvec = mem_cgroup_lruvec(memcg, pgdat); + mod_memcg_lruvec_state(lruvec, idx, nr); + } else { + struct mem_cgroup_per_node *pn = memcg->nodeinfo[pgdat->node_id]; + + /* preemption is disabled in_nmi(). */ + css_rstat_updated(&memcg->css, smp_processor_id()); + if (idx == NR_SLAB_RECLAIMABLE_B) + atomic_add(nr, &pn->slab_reclaimable); + else + atomic_add(nr, &pn->slab_unreclaimable); + } +} +#else +static inline void account_slab_nmi_safe(struct mem_cgroup *memcg, + struct pglist_data *pgdat, + enum node_stat_item idx, int nr) { - struct mem_cgroup *memcg; struct lruvec *lruvec; - rcu_read_lock(); - memcg = obj_cgroup_memcg(objcg); lruvec = mem_cgroup_lruvec(memcg, pgdat); mod_memcg_lruvec_state(lruvec, idx, nr); - rcu_read_unlock(); } +#endif -int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, - gfp_t gfp, bool new_slab) +static inline void mod_objcg_mlstate(struct obj_cgroup *objcg, + struct pglist_data *pgdat, + enum node_stat_item idx, int nr) { - unsigned int objects = objs_per_slab(s, slab); - unsigned long memcg_data; - void *vec; - - gfp &= ~OBJCGS_CLEAR_MASK; - vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp, - slab_nid(slab)); - if (!vec) - return -ENOMEM; - - memcg_data = (unsigned long) vec | MEMCG_DATA_OBJCGS; - if (new_slab) { - /* - * If the slab is brand new and nobody can yet access its - * memcg_data, no synchronization is required and memcg_data can - * be simply assigned. - */ - slab->memcg_data = memcg_data; - } else if (cmpxchg(&slab->memcg_data, 0, memcg_data)) { - /* - * If the slab is already in use, somebody can allocate and - * assign obj_cgroups in parallel. In this case the existing - * objcg vector should be reused. - */ - kfree(vec); - return 0; - } + struct mem_cgroup *memcg; - kmemleak_not_leak(vec); - return 0; + rcu_read_lock(); + memcg = obj_cgroup_memcg(objcg); + account_slab_nmi_safe(memcg, pgdat, idx, nr); + rcu_read_unlock(); } static __always_inline -struct mem_cgroup *mem_cgroup_from_obj_folio(struct folio *folio, void *p) +struct mem_cgroup *mem_cgroup_from_obj_slab(struct slab *slab, void *p) { /* * Slab objects are accounted individually, not per-page. * Memcg membership data for each individual object is saved in - * slab->memcg_data. + * slab->obj_exts. */ - if (folio_test_slab(folio)) { - struct obj_cgroup **objcgs; - struct slab *slab; - unsigned int off; - - slab = folio_slab(folio); - objcgs = slab_objcgs(slab); - if (!objcgs) - return NULL; - - off = obj_to_index(slab->slab_cache, slab, p); - if (objcgs[off]) - return obj_cgroup_memcg(objcgs[off]); + struct slabobj_ext *obj_exts; + unsigned int off; + obj_exts = slab_obj_exts(slab); + if (!obj_exts) return NULL; - } - /* - * page_memcg_check() is used here, because in theory we can encounter - * a folio where the slab flag has been cleared already, but - * slab->memcg_data has not been freed yet - * page_memcg_check(page) will guarantee that a proper memory - * cgroup pointer or NULL will be returned. - */ - return page_memcg_check(folio_page(folio, 0)); -} + off = obj_to_index(slab->slab_cache, slab, p); + if (obj_exts[off].objcg) + return obj_cgroup_memcg(obj_exts[off].objcg); -/* - * Returns a pointer to the memory cgroup to which the kernel object is charged. - * - * A passed kernel object can be a slab object, vmalloc object or a generic - * kernel page, so different mechanisms for getting the memory cgroup pointer - * should be used. - * - * In certain cases (e.g. kernel stacks or large kmallocs with SLUB) the caller - * can not know for sure how the kernel object is implemented. - * mem_cgroup_from_obj() can be safely used in such cases. - * - * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(), - * cgroup_mutex, etc. - */ -struct mem_cgroup *mem_cgroup_from_obj(void *p) -{ - struct folio *folio; - - if (mem_cgroup_disabled()) - return NULL; - - if (unlikely(is_vmalloc_addr(p))) - folio = page_folio(vmalloc_to_page(p)); - else - folio = virt_to_folio(p); - - return mem_cgroup_from_obj_folio(folio, p); + return NULL; } /* * Returns a pointer to the memory cgroup to which the kernel object is charged. - * Similar to mem_cgroup_from_obj(), but faster and not suitable for objects, - * allocated using vmalloc(). + * It is not suitable for objects allocated using vmalloc(). * * A passed kernel object must be a slab object or a generic kernel page. * @@ -2992,10 +2621,15 @@ struct mem_cgroup *mem_cgroup_from_obj(void *p) */ struct mem_cgroup *mem_cgroup_from_slab_obj(void *p) { + struct slab *slab; + if (mem_cgroup_disabled()) return NULL; - return mem_cgroup_from_obj_folio(virt_to_folio(p), p); + slab = virt_to_slab(p); + if (slab) + return mem_cgroup_from_obj_slab(slab, p); + return folio_memcg_check(virt_to_folio(p)); } static struct obj_cgroup *__get_obj_cgroup_from_memcg(struct mem_cgroup *memcg) @@ -3004,46 +2638,125 @@ static struct obj_cgroup *__get_obj_cgroup_from_memcg(struct mem_cgroup *memcg) for (; !mem_cgroup_is_root(memcg); memcg = parent_mem_cgroup(memcg)) { objcg = rcu_dereference(memcg->objcg); - if (objcg && obj_cgroup_tryget(objcg)) + if (likely(objcg && obj_cgroup_tryget(objcg))) break; objcg = NULL; } return objcg; } -__always_inline struct obj_cgroup *get_obj_cgroup_from_current(void) +static struct obj_cgroup *current_objcg_update(void) { - struct obj_cgroup *objcg = NULL; struct mem_cgroup *memcg; + struct obj_cgroup *old, *objcg = NULL; - if (memcg_kmem_bypass()) - return NULL; + do { + /* Atomically drop the update bit. */ + old = xchg(¤t->objcg, NULL); + if (old) { + old = (struct obj_cgroup *) + ((unsigned long)old & ~CURRENT_OBJCG_UPDATE_FLAG); + obj_cgroup_put(old); + + old = NULL; + } - rcu_read_lock(); - if (unlikely(active_memcg())) - memcg = active_memcg(); - else + /* If new objcg is NULL, no reason for the second atomic update. */ + if (!current->mm || (current->flags & PF_KTHREAD)) + return NULL; + + /* + * Release the objcg pointer from the previous iteration, + * if try_cmpxcg() below fails. + */ + if (unlikely(objcg)) { + obj_cgroup_put(objcg); + objcg = NULL; + } + + /* + * Obtain the new objcg pointer. The current task can be + * asynchronously moved to another memcg and the previous + * memcg can be offlined. So let's get the memcg pointer + * and try get a reference to objcg under a rcu read lock. + */ + + rcu_read_lock(); memcg = mem_cgroup_from_task(current); - objcg = __get_obj_cgroup_from_memcg(memcg); - rcu_read_unlock(); + objcg = __get_obj_cgroup_from_memcg(memcg); + rcu_read_unlock(); + + /* + * Try set up a new objcg pointer atomically. If it + * fails, it means the update flag was set concurrently, so + * the whole procedure should be repeated. + */ + } while (!try_cmpxchg(¤t->objcg, &old, objcg)); + return objcg; } -struct obj_cgroup *get_obj_cgroup_from_page(struct page *page) +__always_inline struct obj_cgroup *current_obj_cgroup(void) { + struct mem_cgroup *memcg; struct obj_cgroup *objcg; - if (!memcg_kmem_enabled()) + if (IS_ENABLED(CONFIG_MEMCG_NMI_UNSAFE) && in_nmi()) return NULL; - if (PageMemcgKmem(page)) { - objcg = __folio_objcg(page_folio(page)); + if (in_task()) { + memcg = current->active_memcg; + if (unlikely(memcg)) + goto from_memcg; + + objcg = READ_ONCE(current->objcg); + if (unlikely((unsigned long)objcg & CURRENT_OBJCG_UPDATE_FLAG)) + objcg = current_objcg_update(); + /* + * Objcg reference is kept by the task, so it's safe + * to use the objcg by the current task. + */ + return objcg; + } + + memcg = this_cpu_read(int_active_memcg); + if (unlikely(memcg)) + goto from_memcg; + + return NULL; + +from_memcg: + objcg = NULL; + for (; !mem_cgroup_is_root(memcg); memcg = parent_mem_cgroup(memcg)) { + /* + * Memcg pointer is protected by scope (see set_active_memcg()) + * and is pinning the corresponding objcg, so objcg can't go + * away and can be used within the scope without any additional + * protection. + */ + objcg = rcu_dereference_check(memcg->objcg, 1); + if (likely(objcg)) + break; + } + + return objcg; +} + +struct obj_cgroup *get_obj_cgroup_from_folio(struct folio *folio) +{ + struct obj_cgroup *objcg; + + if (!memcg_kmem_online()) + return NULL; + + if (folio_memcg_kmem(folio)) { + objcg = __folio_objcg(folio); obj_cgroup_get(objcg); } else { struct mem_cgroup *memcg; rcu_read_lock(); - memcg = __folio_memcg(page_folio(page)); + memcg = __folio_memcg(folio); if (memcg) objcg = __get_obj_cgroup_from_memcg(memcg); else @@ -3053,17 +2766,23 @@ struct obj_cgroup *get_obj_cgroup_from_page(struct page *page) return objcg; } -static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages) +#ifdef CONFIG_MEMCG_NMI_SAFETY_REQUIRES_ATOMIC +static inline void account_kmem_nmi_safe(struct mem_cgroup *memcg, int val) { - mod_memcg_state(memcg, MEMCG_KMEM, nr_pages); - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { - if (nr_pages > 0) - page_counter_charge(&memcg->kmem, nr_pages); - else - page_counter_uncharge(&memcg->kmem, -nr_pages); + if (likely(!in_nmi())) { + mod_memcg_state(memcg, MEMCG_KMEM, val); + } else { + /* preemption is disabled in_nmi(). */ + css_rstat_updated(&memcg->css, smp_processor_id()); + atomic_add(val, &memcg->kmem_stat); } } - +#else +static inline void account_kmem_nmi_safe(struct mem_cgroup *memcg, int val) +{ + mod_memcg_state(memcg, MEMCG_KMEM, val); +} +#endif /* * obj_cgroup_uncharge_pages: uncharge a number of kernel pages from a objcg @@ -3077,8 +2796,10 @@ static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, memcg = get_mem_cgroup_from_objcg(objcg); - memcg_account_kmem(memcg, -nr_pages); - refill_stock(memcg, nr_pages); + account_kmem_nmi_safe(memcg, -nr_pages); + memcg1_account_kmem(memcg, -nr_pages); + if (!mem_cgroup_is_root(memcg)) + refill_stock(memcg, nr_pages); css_put(&memcg->css); } @@ -3103,13 +2824,31 @@ static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp, if (ret) goto out; - memcg_account_kmem(memcg, nr_pages); + account_kmem_nmi_safe(memcg, nr_pages); + memcg1_account_kmem(memcg, nr_pages); out: css_put(&memcg->css); return ret; } +static struct obj_cgroup *page_objcg(const struct page *page) +{ + unsigned long memcg_data = page->memcg_data; + + if (mem_cgroup_disabled() || !memcg_data) + return NULL; + + VM_BUG_ON_PAGE((memcg_data & OBJEXTS_FLAGS_MASK) != MEMCG_DATA_KMEM, + page); + return (struct obj_cgroup *)(memcg_data - MEMCG_DATA_KMEM); +} + +static void page_set_objcg(struct page *page, const struct obj_cgroup *objcg) +{ + page->memcg_data = (unsigned long)objcg | MEMCG_DATA_KMEM; +} + /** * __memcg_kmem_charge_page: charge a kmem page to the current memory cgroup * @page: page to charge @@ -3123,15 +2862,14 @@ int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order) struct obj_cgroup *objcg; int ret = 0; - objcg = get_obj_cgroup_from_current(); + objcg = current_obj_cgroup(); if (objcg) { ret = obj_cgroup_charge_pages(objcg, gfp, 1 << order); if (!ret) { - page->memcg_data = (unsigned long)objcg | - MEMCG_DATA_KMEM; + obj_cgroup_get(objcg); + page_set_objcg(page, objcg); return 0; } - obj_cgroup_put(objcg); } return ret; } @@ -3143,43 +2881,28 @@ int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order) */ void __memcg_kmem_uncharge_page(struct page *page, int order) { - struct folio *folio = page_folio(page); - struct obj_cgroup *objcg; + struct obj_cgroup *objcg = page_objcg(page); unsigned int nr_pages = 1 << order; - if (!folio_memcg_kmem(folio)) + if (!objcg) return; - objcg = __folio_objcg(folio); obj_cgroup_uncharge_pages(objcg, nr_pages); - folio->memcg_data = 0; + page->memcg_data = 0; obj_cgroup_put(objcg); } -void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, - enum node_stat_item idx, int nr) +static void __account_obj_stock(struct obj_cgroup *objcg, + struct obj_stock_pcp *stock, int nr, + struct pglist_data *pgdat, enum node_stat_item idx) { - struct memcg_stock_pcp *stock; - struct obj_cgroup *old = NULL; - unsigned long flags; int *bytes; - local_lock_irqsave(&memcg_stock.stock_lock, flags); - stock = this_cpu_ptr(&memcg_stock); - /* * Save vmstat data in stock and skip vmstat array update unless - * accumulating over a page of vmstat data or when pgdat or idx - * changes. + * accumulating over a page of vmstat data or when pgdat changes. */ - if (stock->cached_objcg != objcg) { - old = drain_obj_stock(stock); - obj_cgroup_get(objcg); - stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes) - ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0; - stock->cached_objcg = objcg; - stock->cached_pgdat = pgdat; - } else if (stock->cached_pgdat != pgdat) { + if (stock->cached_pgdat != pgdat) { /* Flush the existing cached vmstat data */ struct pglist_data *oldpg = stock->cached_pgdat; @@ -3216,37 +2939,37 @@ void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, } if (nr) mod_objcg_mlstate(objcg, pgdat, idx, nr); - - local_unlock_irqrestore(&memcg_stock.stock_lock, flags); - if (old) - obj_cgroup_put(old); } -static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes) +static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes, + struct pglist_data *pgdat, enum node_stat_item idx) { - struct memcg_stock_pcp *stock; - unsigned long flags; + struct obj_stock_pcp *stock; bool ret = false; - local_lock_irqsave(&memcg_stock.stock_lock, flags); + if (!local_trylock(&obj_stock.lock)) + return ret; - stock = this_cpu_ptr(&memcg_stock); - if (objcg == stock->cached_objcg && stock->nr_bytes >= nr_bytes) { + stock = this_cpu_ptr(&obj_stock); + if (objcg == READ_ONCE(stock->cached_objcg) && stock->nr_bytes >= nr_bytes) { stock->nr_bytes -= nr_bytes; ret = true; + + if (pgdat) + __account_obj_stock(objcg, stock, nr_bytes, pgdat, idx); } - local_unlock_irqrestore(&memcg_stock.stock_lock, flags); + local_unlock(&obj_stock.lock); return ret; } -static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock) +static void drain_obj_stock(struct obj_stock_pcp *stock) { - struct obj_cgroup *old = stock->cached_objcg; + struct obj_cgroup *old = READ_ONCE(stock->cached_objcg); if (!old) - return NULL; + return; if (stock->nr_bytes) { unsigned int nr_pages = stock->nr_bytes >> PAGE_SHIFT; @@ -3257,8 +2980,10 @@ static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock) memcg = get_mem_cgroup_from_objcg(old); - memcg_account_kmem(memcg, -nr_pages); - __refill_stock(memcg, nr_pages); + mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages); + memcg1_account_kmem(memcg, -nr_pages); + if (!mem_cgroup_is_root(memcg)) + memcg_uncharge(memcg, nr_pages); css_put(&memcg->css); } @@ -3296,68 +3021,77 @@ static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock) stock->cached_pgdat = NULL; } - stock->cached_objcg = NULL; - /* - * The `old' objects needs to be released by the caller via - * obj_cgroup_put() outside of memcg_stock_pcp::stock_lock. - */ - return old; + WRITE_ONCE(stock->cached_objcg, NULL); + obj_cgroup_put(old); } -static bool obj_stock_flush_required(struct memcg_stock_pcp *stock, +static bool obj_stock_flush_required(struct obj_stock_pcp *stock, struct mem_cgroup *root_memcg) { + struct obj_cgroup *objcg = READ_ONCE(stock->cached_objcg); struct mem_cgroup *memcg; + bool flush = false; - if (stock->cached_objcg) { - memcg = obj_cgroup_memcg(stock->cached_objcg); + rcu_read_lock(); + if (objcg) { + memcg = obj_cgroup_memcg(objcg); if (memcg && mem_cgroup_is_descendant(memcg, root_memcg)) - return true; + flush = true; } + rcu_read_unlock(); - return false; + return flush; } static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes, - bool allow_uncharge) + bool allow_uncharge, int nr_acct, struct pglist_data *pgdat, + enum node_stat_item idx) { - struct memcg_stock_pcp *stock; - struct obj_cgroup *old = NULL; - unsigned long flags; + struct obj_stock_pcp *stock; unsigned int nr_pages = 0; - local_lock_irqsave(&memcg_stock.stock_lock, flags); + if (!local_trylock(&obj_stock.lock)) { + if (pgdat) + mod_objcg_mlstate(objcg, pgdat, idx, nr_bytes); + nr_pages = nr_bytes >> PAGE_SHIFT; + nr_bytes = nr_bytes & (PAGE_SIZE - 1); + atomic_add(nr_bytes, &objcg->nr_charged_bytes); + goto out; + } - stock = this_cpu_ptr(&memcg_stock); - if (stock->cached_objcg != objcg) { /* reset if necessary */ - old = drain_obj_stock(stock); + stock = this_cpu_ptr(&obj_stock); + if (READ_ONCE(stock->cached_objcg) != objcg) { /* reset if necessary */ + drain_obj_stock(stock); obj_cgroup_get(objcg); - stock->cached_objcg = objcg; stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes) ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0; + WRITE_ONCE(stock->cached_objcg, objcg); + allow_uncharge = true; /* Allow uncharge when objcg changes */ } stock->nr_bytes += nr_bytes; + if (pgdat) + __account_obj_stock(objcg, stock, nr_acct, pgdat, idx); + if (allow_uncharge && (stock->nr_bytes > PAGE_SIZE)) { nr_pages = stock->nr_bytes >> PAGE_SHIFT; stock->nr_bytes &= (PAGE_SIZE - 1); } - local_unlock_irqrestore(&memcg_stock.stock_lock, flags); - if (old) - obj_cgroup_put(old); - + local_unlock(&obj_stock.lock); +out: if (nr_pages) obj_cgroup_uncharge_pages(objcg, nr_pages); } -int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size) +static int obj_cgroup_charge_account(struct obj_cgroup *objcg, gfp_t gfp, size_t size, + struct pglist_data *pgdat, enum node_stat_item idx) { unsigned int nr_pages, nr_bytes; int ret; - if (consume_obj_stock(objcg, size)) + if (likely(consume_obj_stock(objcg, size, pgdat, idx))) return 0; /* @@ -3390,282 +3124,167 @@ int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size) nr_pages += 1; ret = obj_cgroup_charge_pages(objcg, gfp, nr_pages); - if (!ret && nr_bytes) - refill_obj_stock(objcg, PAGE_SIZE - nr_bytes, false); + if (!ret && (nr_bytes || pgdat)) + refill_obj_stock(objcg, nr_bytes ? PAGE_SIZE - nr_bytes : 0, + false, size, pgdat, idx); return ret; } -void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size) +int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size) { - refill_obj_stock(objcg, size, true); + return obj_cgroup_charge_account(objcg, gfp, size, NULL, 0); } -#endif /* CONFIG_MEMCG_KMEM */ - -/* - * Because page_memcg(head) is not set on tails, set it now. - */ -void split_page_memcg(struct page *head, unsigned int nr) +void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size) { - struct folio *folio = page_folio(head); - struct mem_cgroup *memcg = folio_memcg(folio); - int i; - - if (mem_cgroup_disabled() || !memcg) - return; - - for (i = 1; i < nr; i++) - folio_page(folio, i)->memcg_data = folio->memcg_data; + refill_obj_stock(objcg, size, true, 0, NULL, 0); +} - if (folio_memcg_kmem(folio)) - obj_cgroup_get_many(__folio_objcg(folio), nr - 1); - else - css_get_many(&memcg->css, nr - 1); +static inline size_t obj_full_size(struct kmem_cache *s) +{ + /* + * For each accounted object there is an extra space which is used + * to store obj_cgroup membership. Charge it too. + */ + return s->size + sizeof(struct obj_cgroup *); } -#ifdef CONFIG_SWAP -/** - * mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record. - * @entry: swap entry to be moved - * @from: mem_cgroup which the entry is moved from - * @to: mem_cgroup which the entry is moved to - * - * It succeeds only when the swap_cgroup's record for this entry is the same - * as the mem_cgroup's id of @from. - * - * Returns 0 on success, -EINVAL on failure. - * - * The caller must have charged to @to, IOW, called page_counter_charge() about - * both res and memsw, and called css_get(). - */ -static int mem_cgroup_move_swap_account(swp_entry_t entry, - struct mem_cgroup *from, struct mem_cgroup *to) +bool __memcg_slab_post_alloc_hook(struct kmem_cache *s, struct list_lru *lru, + gfp_t flags, size_t size, void **p) { - unsigned short old_id, new_id; + struct obj_cgroup *objcg; + struct slab *slab; + unsigned long off; + size_t i; - old_id = mem_cgroup_id(from); - new_id = mem_cgroup_id(to); + /* + * The obtained objcg pointer is safe to use within the current scope, + * defined by current task or set_active_memcg() pair. + * obj_cgroup_get() is used to get a permanent reference. + */ + objcg = current_obj_cgroup(); + if (!objcg) + return true; - if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) { - mod_memcg_state(from, MEMCG_SWAP, -1); - mod_memcg_state(to, MEMCG_SWAP, 1); - return 0; - } - return -EINVAL; -} -#else -static inline int mem_cgroup_move_swap_account(swp_entry_t entry, - struct mem_cgroup *from, struct mem_cgroup *to) -{ - return -EINVAL; -} -#endif + /* + * slab_alloc_node() avoids the NULL check, so we might be called with a + * single NULL object. kmem_cache_alloc_bulk() aborts if it can't fill + * the whole requested size. + * return success as there's nothing to free back + */ + if (unlikely(*p == NULL)) + return true; -static DEFINE_MUTEX(memcg_max_mutex); + flags &= gfp_allowed_mask; -static int mem_cgroup_resize_max(struct mem_cgroup *memcg, - unsigned long max, bool memsw) -{ - bool enlarge = false; - bool drained = false; - int ret; - bool limits_invariant; - struct page_counter *counter = memsw ? &memcg->memsw : &memcg->memory; + if (lru) { + int ret; + struct mem_cgroup *memcg; - do { - if (signal_pending(current)) { - ret = -EINTR; - break; - } + memcg = get_mem_cgroup_from_objcg(objcg); + ret = memcg_list_lru_alloc(memcg, lru, flags); + css_put(&memcg->css); - mutex_lock(&memcg_max_mutex); - /* - * Make sure that the new limit (memsw or memory limit) doesn't - * break our basic invariant rule memory.max <= memsw.max. - */ - limits_invariant = memsw ? max >= READ_ONCE(memcg->memory.max) : - max <= memcg->memsw.max; - if (!limits_invariant) { - mutex_unlock(&memcg_max_mutex); - ret = -EINVAL; - break; - } - if (max > counter->max) - enlarge = true; - ret = page_counter_set_max(counter, max); - mutex_unlock(&memcg_max_mutex); + if (ret) + return false; + } - if (!ret) - break; + for (i = 0; i < size; i++) { + slab = virt_to_slab(p[i]); - if (!drained) { - drain_all_stock(memcg); - drained = true; + if (!slab_obj_exts(slab) && + alloc_slab_obj_exts(slab, s, flags, false)) { continue; } - if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, - memsw ? 0 : MEMCG_RECLAIM_MAY_SWAP, - NULL)) { - ret = -EBUSY; - break; - } - } while (true); + /* + * if we fail and size is 1, memcg_alloc_abort_single() will + * just free the object, which is ok as we have not assigned + * objcg to its obj_ext yet + * + * for larger sizes, kmem_cache_free_bulk() will uncharge + * any objects that were already charged and obj_ext assigned + * + * TODO: we could batch this until slab_pgdat(slab) changes + * between iterations, with a more complicated undo + */ + if (obj_cgroup_charge_account(objcg, flags, obj_full_size(s), + slab_pgdat(slab), cache_vmstat_idx(s))) + return false; - if (!ret && enlarge) - memcg_oom_recover(memcg); + off = obj_to_index(s, slab, p[i]); + obj_cgroup_get(objcg); + slab_obj_exts(slab)[off].objcg = objcg; + } - return ret; + return true; } -unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order, - gfp_t gfp_mask, - unsigned long *total_scanned) +void __memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, + void **p, int objects, struct slabobj_ext *obj_exts) { - unsigned long nr_reclaimed = 0; - struct mem_cgroup_per_node *mz, *next_mz = NULL; - unsigned long reclaimed; - int loop = 0; - struct mem_cgroup_tree_per_node *mctz; - unsigned long excess; - - if (order > 0) - return 0; - - mctz = soft_limit_tree.rb_tree_per_node[pgdat->node_id]; - - /* - * Do not even bother to check the largest node if the root - * is empty. Do it lockless to prevent lock bouncing. Races - * are acceptable as soft limit is best effort anyway. - */ - if (!mctz || RB_EMPTY_ROOT(&mctz->rb_root)) - return 0; - - /* - * This loop can run a while, specially if mem_cgroup's continuously - * keep exceeding their soft limit and putting the system under - * pressure - */ - do { - if (next_mz) - mz = next_mz; - else - mz = mem_cgroup_largest_soft_limit_node(mctz); - if (!mz) - break; + size_t obj_size = obj_full_size(s); - reclaimed = mem_cgroup_soft_reclaim(mz->memcg, pgdat, - gfp_mask, total_scanned); - nr_reclaimed += reclaimed; - spin_lock_irq(&mctz->lock); + for (int i = 0; i < objects; i++) { + struct obj_cgroup *objcg; + unsigned int off; - /* - * If we failed to reclaim anything from this memory cgroup - * it is time to move on to the next cgroup - */ - next_mz = NULL; - if (!reclaimed) - next_mz = __mem_cgroup_largest_soft_limit_node(mctz); + off = obj_to_index(s, slab, p[i]); + objcg = obj_exts[off].objcg; + if (!objcg) + continue; - excess = soft_limit_excess(mz->memcg); - /* - * One school of thought says that we should not add - * back the node to the tree if reclaim returns 0. - * But our reclaim could return 0, simply because due - * to priority we are exposing a smaller subset of - * memory to reclaim from. Consider this as a longer - * term TODO. - */ - /* If excess == 0, no tree ops */ - __mem_cgroup_insert_exceeded(mz, mctz, excess); - spin_unlock_irq(&mctz->lock); - css_put(&mz->memcg->css); - loop++; - /* - * Could not reclaim anything and there are no more - * mem cgroups to try or we seem to be looping without - * reclaiming anything. - */ - if (!nr_reclaimed && - (next_mz == NULL || - loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS)) - break; - } while (!nr_reclaimed); - if (next_mz) - css_put(&next_mz->memcg->css); - return nr_reclaimed; + obj_exts[off].objcg = NULL; + refill_obj_stock(objcg, obj_size, true, -obj_size, + slab_pgdat(slab), cache_vmstat_idx(s)); + obj_cgroup_put(objcg); + } } /* - * Reclaims as many pages from the given memcg as possible. - * - * Caller is responsible for holding css reference for memcg. + * The objcg is only set on the first page, so transfer it to all the + * other pages. */ -static int mem_cgroup_force_empty(struct mem_cgroup *memcg) +void split_page_memcg(struct page *page, unsigned order) { - int nr_retries = MAX_RECLAIM_RETRIES; - - /* we call try-to-free pages for make this cgroup empty */ - lru_add_drain_all(); - - drain_all_stock(memcg); + struct obj_cgroup *objcg = page_objcg(page); + unsigned int i, nr = 1 << order; - /* try to free all pages in this cgroup */ - while (nr_retries && page_counter_read(&memcg->memory)) { - if (signal_pending(current)) - return -EINTR; - - if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, - MEMCG_RECLAIM_MAY_SWAP, - NULL)) - nr_retries--; - } - - return 0; -} - -static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, - loff_t off) -{ - struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + if (!objcg) + return; - if (mem_cgroup_is_root(memcg)) - return -EINVAL; - return mem_cgroup_force_empty(memcg) ?: nbytes; -} + for (i = 1; i < nr; i++) + page_set_objcg(&page[i], objcg); -static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css, - struct cftype *cft) -{ - return 1; + obj_cgroup_get_many(objcg, nr - 1); } -static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css, - struct cftype *cft, u64 val) +void folio_split_memcg_refs(struct folio *folio, unsigned old_order, + unsigned new_order) { - if (val == 1) - return 0; + unsigned new_refs; - pr_warn_once("Non-hierarchical mode is deprecated. " - "Please report your usecase to linux-mm@kvack.org if you " - "depend on this functionality.\n"); + if (mem_cgroup_disabled() || !folio_memcg_charged(folio)) + return; - return -EINVAL; + new_refs = (1 << (old_order - new_order)) - 1; + css_get_many(&__folio_memcg(folio)->css, new_refs); } -static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) +unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) { unsigned long val; if (mem_cgroup_is_root(memcg)) { - mem_cgroup_flush_stats(); - val = memcg_page_state(memcg, NR_FILE_PAGES) + - memcg_page_state(memcg, NR_ANON_MAPPED); + /* + * Approximate root's usage from global state. This isn't + * perfect, but the root usage was always an approximation. + */ + val = global_node_page_state(NR_FILE_PAGES) + + global_node_page_state(NR_ANON_MAPPED); if (swap) - val += memcg_page_state(memcg, MEMCG_SWAP); + val += total_swap_pages - get_nr_swap_pages(); } else { if (!swap) val = page_counter_read(&memcg->memory); @@ -3675,58 +3294,6 @@ static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) return val; } -enum { - RES_USAGE, - RES_LIMIT, - RES_MAX_USAGE, - RES_FAILCNT, - RES_SOFT_LIMIT, -}; - -static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, - struct cftype *cft) -{ - struct mem_cgroup *memcg = mem_cgroup_from_css(css); - struct page_counter *counter; - - switch (MEMFILE_TYPE(cft->private)) { - case _MEM: - counter = &memcg->memory; - break; - case _MEMSWAP: - counter = &memcg->memsw; - break; - case _KMEM: - counter = &memcg->kmem; - break; - case _TCP: - counter = &memcg->tcpmem; - break; - default: - BUG(); - } - - switch (MEMFILE_ATTR(cft->private)) { - case RES_USAGE: - if (counter == &memcg->memory) - return (u64)mem_cgroup_usage(memcg, false) * PAGE_SIZE; - if (counter == &memcg->memsw) - return (u64)mem_cgroup_usage(memcg, true) * PAGE_SIZE; - return (u64)page_counter_read(counter) * PAGE_SIZE; - case RES_LIMIT: - return (u64)counter->max * PAGE_SIZE; - case RES_MAX_USAGE: - return (u64)counter->watermark * PAGE_SIZE; - case RES_FAILCNT: - return counter->failcnt; - case RES_SOFT_LIMIT: - return (u64)memcg->soft_limit * PAGE_SIZE; - default: - BUG(); - } -} - -#ifdef CONFIG_MEMCG_KMEM static int memcg_online_kmem(struct mem_cgroup *memcg) { struct obj_cgroup *objcg; @@ -3743,8 +3310,10 @@ static int memcg_online_kmem(struct mem_cgroup *memcg) objcg->memcg = memcg; rcu_assign_pointer(memcg->objcg, objcg); + obj_cgroup_get(objcg); + memcg->orig_objcg = objcg; - static_branch_enable(&memcg_kmem_enabled_key); + static_branch_enable(&memcg_kmem_online_key); memcg->kmemcg_id = memcg->id.id; @@ -3765,765 +3334,13 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg) if (!parent) parent = root_mem_cgroup; - memcg_reparent_objcgs(memcg, parent); - - /* - * After we have finished memcg_reparent_objcgs(), all list_lrus - * corresponding to this cgroup are guaranteed to remain empty. - * The ordering is imposed by list_lru_node->lock taken by - * memcg_reparent_list_lrus(). - */ memcg_reparent_list_lrus(memcg, parent); -} -#else -static int memcg_online_kmem(struct mem_cgroup *memcg) -{ - return 0; -} -static void memcg_offline_kmem(struct mem_cgroup *memcg) -{ -} -#endif /* CONFIG_MEMCG_KMEM */ - -static int memcg_update_tcp_max(struct mem_cgroup *memcg, unsigned long max) -{ - int ret; - - mutex_lock(&memcg_max_mutex); - - ret = page_counter_set_max(&memcg->tcpmem, max); - if (ret) - goto out; - - if (!memcg->tcpmem_active) { - /* - * The active flag needs to be written after the static_key - * update. This is what guarantees that the socket activation - * function is the last one to run. See mem_cgroup_sk_alloc() - * for details, and note that we don't mark any socket as - * belonging to this memcg until that flag is up. - * - * We need to do this, because static_keys will span multiple - * sites, but we can't control their order. If we mark a socket - * as accounted, but the accounting functions are not patched in - * yet, we'll lose accounting. - * - * We never race with the readers in mem_cgroup_sk_alloc(), - * because when this value change, the code to process it is not - * patched in yet. - */ - static_branch_inc(&memcg_sockets_enabled_key); - memcg->tcpmem_active = true; - } -out: - mutex_unlock(&memcg_max_mutex); - return ret; -} - -/* - * The user of this function is... - * RES_LIMIT. - */ -static ssize_t mem_cgroup_write(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) -{ - struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); - unsigned long nr_pages; - int ret; - - buf = strstrip(buf); - ret = page_counter_memparse(buf, "-1", &nr_pages); - if (ret) - return ret; - - switch (MEMFILE_ATTR(of_cft(of)->private)) { - case RES_LIMIT: - if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */ - ret = -EINVAL; - break; - } - switch (MEMFILE_TYPE(of_cft(of)->private)) { - case _MEM: - ret = mem_cgroup_resize_max(memcg, nr_pages, false); - break; - case _MEMSWAP: - ret = mem_cgroup_resize_max(memcg, nr_pages, true); - break; - case _KMEM: - /* kmem.limit_in_bytes is deprecated. */ - ret = -EOPNOTSUPP; - break; - case _TCP: - ret = memcg_update_tcp_max(memcg, nr_pages); - break; - } - break; - case RES_SOFT_LIMIT: - if (IS_ENABLED(CONFIG_PREEMPT_RT)) { - ret = -EOPNOTSUPP; - } else { - memcg->soft_limit = nr_pages; - ret = 0; - } - break; - } - return ret ?: nbytes; -} - -static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf, - size_t nbytes, loff_t off) -{ - struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); - struct page_counter *counter; - - switch (MEMFILE_TYPE(of_cft(of)->private)) { - case _MEM: - counter = &memcg->memory; - break; - case _MEMSWAP: - counter = &memcg->memsw; - break; - case _KMEM: - counter = &memcg->kmem; - break; - case _TCP: - counter = &memcg->tcpmem; - break; - default: - BUG(); - } - - switch (MEMFILE_ATTR(of_cft(of)->private)) { - case RES_MAX_USAGE: - page_counter_reset_watermark(counter); - break; - case RES_FAILCNT: - counter->failcnt = 0; - break; - default: - BUG(); - } - - return nbytes; -} - -static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css, - struct cftype *cft) -{ - return mem_cgroup_from_css(css)->move_charge_at_immigrate; -} - -#ifdef CONFIG_MMU -static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, - struct cftype *cft, u64 val) -{ - struct mem_cgroup *memcg = mem_cgroup_from_css(css); - - if (val & ~MOVE_MASK) - return -EINVAL; - - /* - * No kind of locking is needed in here, because ->can_attach() will - * check this value once in the beginning of the process, and then carry - * on with stale data. This means that changes to this value will only - * affect task migrations starting after the change. - */ - memcg->move_charge_at_immigrate = val; - return 0; -} -#else -static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css, - struct cftype *cft, u64 val) -{ - return -ENOSYS; -} -#endif - -#ifdef CONFIG_NUMA - -#define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE)) -#define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON)) -#define LRU_ALL ((1 << NR_LRU_LISTS) - 1) - -static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, - int nid, unsigned int lru_mask, bool tree) -{ - struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid)); - unsigned long nr = 0; - enum lru_list lru; - - VM_BUG_ON((unsigned)nid >= nr_node_ids); - - for_each_lru(lru) { - if (!(BIT(lru) & lru_mask)) - continue; - if (tree) - nr += lruvec_page_state(lruvec, NR_LRU_BASE + lru); - else - nr += lruvec_page_state_local(lruvec, NR_LRU_BASE + lru); - } - return nr; -} - -static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg, - unsigned int lru_mask, - bool tree) -{ - unsigned long nr = 0; - enum lru_list lru; - - for_each_lru(lru) { - if (!(BIT(lru) & lru_mask)) - continue; - if (tree) - nr += memcg_page_state(memcg, NR_LRU_BASE + lru); - else - nr += memcg_page_state_local(memcg, NR_LRU_BASE + lru); - } - return nr; -} - -static int memcg_numa_stat_show(struct seq_file *m, void *v) -{ - struct numa_stat { - const char *name; - unsigned int lru_mask; - }; - - static const struct numa_stat stats[] = { - { "total", LRU_ALL }, - { "file", LRU_ALL_FILE }, - { "anon", LRU_ALL_ANON }, - { "unevictable", BIT(LRU_UNEVICTABLE) }, - }; - const struct numa_stat *stat; - int nid; - struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - - mem_cgroup_flush_stats(); - - for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { - seq_printf(m, "%s=%lu", stat->name, - mem_cgroup_nr_lru_pages(memcg, stat->lru_mask, - false)); - for_each_node_state(nid, N_MEMORY) - seq_printf(m, " N%d=%lu", nid, - mem_cgroup_node_nr_lru_pages(memcg, nid, - stat->lru_mask, false)); - seq_putc(m, '\n'); - } - - for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) { - - seq_printf(m, "hierarchical_%s=%lu", stat->name, - mem_cgroup_nr_lru_pages(memcg, stat->lru_mask, - true)); - for_each_node_state(nid, N_MEMORY) - seq_printf(m, " N%d=%lu", nid, - mem_cgroup_node_nr_lru_pages(memcg, nid, - stat->lru_mask, true)); - seq_putc(m, '\n'); - } - - return 0; -} -#endif /* CONFIG_NUMA */ - -static const unsigned int memcg1_stats[] = { - NR_FILE_PAGES, - NR_ANON_MAPPED, -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - NR_ANON_THPS, -#endif - NR_SHMEM, - NR_FILE_MAPPED, - NR_FILE_DIRTY, - NR_WRITEBACK, - WORKINGSET_REFAULT_ANON, - WORKINGSET_REFAULT_FILE, - MEMCG_SWAP, -}; - -static const char *const memcg1_stat_names[] = { - "cache", - "rss", -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - "rss_huge", -#endif - "shmem", - "mapped_file", - "dirty", - "writeback", - "workingset_refault_anon", - "workingset_refault_file", - "swap", -}; - -/* Universal VM events cgroup1 shows, original sort order */ -static const unsigned int memcg1_events[] = { - PGPGIN, - PGPGOUT, - PGFAULT, - PGMAJFAULT, -}; - -static int memcg_stat_show(struct seq_file *m, void *v) -{ - struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - unsigned long memory, memsw; - struct mem_cgroup *mi; - unsigned int i; - - BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats)); - - mem_cgroup_flush_stats(); - - for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { - unsigned long nr; - - if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account()) - continue; - nr = memcg_page_state_local(memcg, memcg1_stats[i]); - seq_printf(m, "%s %lu\n", memcg1_stat_names[i], - nr * memcg_page_state_unit(memcg1_stats[i])); - } - - for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) - seq_printf(m, "%s %lu\n", vm_event_name(memcg1_events[i]), - memcg_events_local(memcg, memcg1_events[i])); - - for (i = 0; i < NR_LRU_LISTS; i++) - seq_printf(m, "%s %lu\n", lru_list_name(i), - memcg_page_state_local(memcg, NR_LRU_BASE + i) * - PAGE_SIZE); - - /* Hierarchical information */ - memory = memsw = PAGE_COUNTER_MAX; - for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) { - memory = min(memory, READ_ONCE(mi->memory.max)); - memsw = min(memsw, READ_ONCE(mi->memsw.max)); - } - seq_printf(m, "hierarchical_memory_limit %llu\n", - (u64)memory * PAGE_SIZE); - if (do_memsw_account()) - seq_printf(m, "hierarchical_memsw_limit %llu\n", - (u64)memsw * PAGE_SIZE); - - for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) { - unsigned long nr; - - if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account()) - continue; - nr = memcg_page_state(memcg, memcg1_stats[i]); - seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i], - (u64)nr * memcg_page_state_unit(memcg1_stats[i])); - } - - for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) - seq_printf(m, "total_%s %llu\n", - vm_event_name(memcg1_events[i]), - (u64)memcg_events(memcg, memcg1_events[i])); - - for (i = 0; i < NR_LRU_LISTS; i++) - seq_printf(m, "total_%s %llu\n", lru_list_name(i), - (u64)memcg_page_state(memcg, NR_LRU_BASE + i) * - PAGE_SIZE); - -#ifdef CONFIG_DEBUG_VM - { - pg_data_t *pgdat; - struct mem_cgroup_per_node *mz; - unsigned long anon_cost = 0; - unsigned long file_cost = 0; - - for_each_online_pgdat(pgdat) { - mz = memcg->nodeinfo[pgdat->node_id]; - - anon_cost += mz->lruvec.anon_cost; - file_cost += mz->lruvec.file_cost; - } - seq_printf(m, "anon_cost %lu\n", anon_cost); - seq_printf(m, "file_cost %lu\n", file_cost); - } -#endif - - return 0; -} - -static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css, - struct cftype *cft) -{ - struct mem_cgroup *memcg = mem_cgroup_from_css(css); - - return mem_cgroup_swappiness(memcg); -} - -static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css, - struct cftype *cft, u64 val) -{ - struct mem_cgroup *memcg = mem_cgroup_from_css(css); - - if (val > 200) - return -EINVAL; - - if (!mem_cgroup_is_root(memcg)) - memcg->swappiness = val; - else - vm_swappiness = val; - - return 0; -} - -static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap) -{ - struct mem_cgroup_threshold_ary *t; - unsigned long usage; - int i; - - rcu_read_lock(); - if (!swap) - t = rcu_dereference(memcg->thresholds.primary); - else - t = rcu_dereference(memcg->memsw_thresholds.primary); - - if (!t) - goto unlock; - - usage = mem_cgroup_usage(memcg, swap); /* - * current_threshold points to threshold just below or equal to usage. - * If it's not true, a threshold was crossed after last - * call of __mem_cgroup_threshold(). + * Objcg's reparenting must be after list_lru's, make sure list_lru + * helpers won't use parent's list_lru until child is drained. */ - i = t->current_threshold; - - /* - * Iterate backward over array of thresholds starting from - * current_threshold and check if a threshold is crossed. - * If none of thresholds below usage is crossed, we read - * only one element of the array here. - */ - for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--) - eventfd_signal(t->entries[i].eventfd, 1); - - /* i = current_threshold + 1 */ - i++; - - /* - * Iterate forward over array of thresholds starting from - * current_threshold+1 and check if a threshold is crossed. - * If none of thresholds above usage is crossed, we read - * only one element of the array here. - */ - for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++) - eventfd_signal(t->entries[i].eventfd, 1); - - /* Update current_threshold */ - t->current_threshold = i - 1; -unlock: - rcu_read_unlock(); -} - -static void mem_cgroup_threshold(struct mem_cgroup *memcg) -{ - while (memcg) { - __mem_cgroup_threshold(memcg, false); - if (do_memsw_account()) - __mem_cgroup_threshold(memcg, true); - - memcg = parent_mem_cgroup(memcg); - } -} - -static int compare_thresholds(const void *a, const void *b) -{ - const struct mem_cgroup_threshold *_a = a; - const struct mem_cgroup_threshold *_b = b; - - if (_a->threshold > _b->threshold) - return 1; - - if (_a->threshold < _b->threshold) - return -1; - - return 0; -} - -static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg) -{ - struct mem_cgroup_eventfd_list *ev; - - spin_lock(&memcg_oom_lock); - - list_for_each_entry(ev, &memcg->oom_notify, list) - eventfd_signal(ev->eventfd, 1); - - spin_unlock(&memcg_oom_lock); - return 0; -} - -static void mem_cgroup_oom_notify(struct mem_cgroup *memcg) -{ - struct mem_cgroup *iter; - - for_each_mem_cgroup_tree(iter, memcg) - mem_cgroup_oom_notify_cb(iter); -} - -static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg, - struct eventfd_ctx *eventfd, const char *args, enum res_type type) -{ - struct mem_cgroup_thresholds *thresholds; - struct mem_cgroup_threshold_ary *new; - unsigned long threshold; - unsigned long usage; - int i, size, ret; - - ret = page_counter_memparse(args, "-1", &threshold); - if (ret) - return ret; - - mutex_lock(&memcg->thresholds_lock); - - if (type == _MEM) { - thresholds = &memcg->thresholds; - usage = mem_cgroup_usage(memcg, false); - } else if (type == _MEMSWAP) { - thresholds = &memcg->memsw_thresholds; - usage = mem_cgroup_usage(memcg, true); - } else - BUG(); - - /* Check if a threshold crossed before adding a new one */ - if (thresholds->primary) - __mem_cgroup_threshold(memcg, type == _MEMSWAP); - - size = thresholds->primary ? thresholds->primary->size + 1 : 1; - - /* Allocate memory for new array of thresholds */ - new = kmalloc(struct_size(new, entries, size), GFP_KERNEL); - if (!new) { - ret = -ENOMEM; - goto unlock; - } - new->size = size; - - /* Copy thresholds (if any) to new array */ - if (thresholds->primary) - memcpy(new->entries, thresholds->primary->entries, - flex_array_size(new, entries, size - 1)); - - /* Add new threshold */ - new->entries[size - 1].eventfd = eventfd; - new->entries[size - 1].threshold = threshold; - - /* Sort thresholds. Registering of new threshold isn't time-critical */ - sort(new->entries, size, sizeof(*new->entries), - compare_thresholds, NULL); - - /* Find current threshold */ - new->current_threshold = -1; - for (i = 0; i < size; i++) { - if (new->entries[i].threshold <= usage) { - /* - * new->current_threshold will not be used until - * rcu_assign_pointer(), so it's safe to increment - * it here. - */ - ++new->current_threshold; - } else - break; - } - - /* Free old spare buffer and save old primary buffer as spare */ - kfree(thresholds->spare); - thresholds->spare = thresholds->primary; - - rcu_assign_pointer(thresholds->primary, new); - - /* To be sure that nobody uses thresholds */ - synchronize_rcu(); - -unlock: - mutex_unlock(&memcg->thresholds_lock); - - return ret; -} - -static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg, - struct eventfd_ctx *eventfd, const char *args) -{ - return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM); -} - -static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg, - struct eventfd_ctx *eventfd, const char *args) -{ - return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP); -} - -static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, - struct eventfd_ctx *eventfd, enum res_type type) -{ - struct mem_cgroup_thresholds *thresholds; - struct mem_cgroup_threshold_ary *new; - unsigned long usage; - int i, j, size, entries; - - mutex_lock(&memcg->thresholds_lock); - - if (type == _MEM) { - thresholds = &memcg->thresholds; - usage = mem_cgroup_usage(memcg, false); - } else if (type == _MEMSWAP) { - thresholds = &memcg->memsw_thresholds; - usage = mem_cgroup_usage(memcg, true); - } else - BUG(); - - if (!thresholds->primary) - goto unlock; - - /* Check if a threshold crossed before removing */ - __mem_cgroup_threshold(memcg, type == _MEMSWAP); - - /* Calculate new number of threshold */ - size = entries = 0; - for (i = 0; i < thresholds->primary->size; i++) { - if (thresholds->primary->entries[i].eventfd != eventfd) - size++; - else - entries++; - } - - new = thresholds->spare; - - /* If no items related to eventfd have been cleared, nothing to do */ - if (!entries) - goto unlock; - - /* Set thresholds array to NULL if we don't have thresholds */ - if (!size) { - kfree(new); - new = NULL; - goto swap_buffers; - } - - new->size = size; - - /* Copy thresholds and find current threshold */ - new->current_threshold = -1; - for (i = 0, j = 0; i < thresholds->primary->size; i++) { - if (thresholds->primary->entries[i].eventfd == eventfd) - continue; - - new->entries[j] = thresholds->primary->entries[i]; - if (new->entries[j].threshold <= usage) { - /* - * new->current_threshold will not be used - * until rcu_assign_pointer(), so it's safe to increment - * it here. - */ - ++new->current_threshold; - } - j++; - } - -swap_buffers: - /* Swap primary and spare array */ - thresholds->spare = thresholds->primary; - - rcu_assign_pointer(thresholds->primary, new); - - /* To be sure that nobody uses thresholds */ - synchronize_rcu(); - - /* If all events are unregistered, free the spare array */ - if (!new) { - kfree(thresholds->spare); - thresholds->spare = NULL; - } -unlock: - mutex_unlock(&memcg->thresholds_lock); -} - -static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg, - struct eventfd_ctx *eventfd) -{ - return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM); -} - -static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg, - struct eventfd_ctx *eventfd) -{ - return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP); -} - -static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg, - struct eventfd_ctx *eventfd, const char *args) -{ - struct mem_cgroup_eventfd_list *event; - - event = kmalloc(sizeof(*event), GFP_KERNEL); - if (!event) - return -ENOMEM; - - spin_lock(&memcg_oom_lock); - - event->eventfd = eventfd; - list_add(&event->list, &memcg->oom_notify); - - /* already in OOM ? */ - if (memcg->under_oom) - eventfd_signal(eventfd, 1); - spin_unlock(&memcg_oom_lock); - - return 0; -} - -static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg, - struct eventfd_ctx *eventfd) -{ - struct mem_cgroup_eventfd_list *ev, *tmp; - - spin_lock(&memcg_oom_lock); - - list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) { - if (ev->eventfd == eventfd) { - list_del(&ev->list); - kfree(ev); - } - } - - spin_unlock(&memcg_oom_lock); -} - -static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v) -{ - struct mem_cgroup *memcg = mem_cgroup_from_seq(sf); - - seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable); - seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom); - seq_printf(sf, "oom_kill %lu\n", - atomic_long_read(&memcg->memory_events[MEMCG_OOM_KILL])); - return 0; -} - -static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css, - struct cftype *cft, u64 val) -{ - struct mem_cgroup *memcg = mem_cgroup_from_css(css); - - /* cannot set to root cgroup and only 0 and 1 are allowed */ - if (mem_cgroup_is_root(memcg) || !((val == 0) || (val == 1))) - return -EINVAL; - - memcg->oom_kill_disable = val; - if (!val) - memcg_oom_recover(memcg); - - return 0; + memcg_reparent_objcgs(memcg, parent); } #ifdef CONFIG_CGROUP_WRITEBACK @@ -4580,7 +3397,7 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages, struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); struct mem_cgroup *parent; - mem_cgroup_flush_stats(); + mem_cgroup_flush_stats_ratelimited(memcg); *pdirty = memcg_page_state(memcg, NR_FILE_DIRTY); *pwriteback = memcg_page_state(memcg, NR_WRITEBACK); @@ -4740,382 +3557,6 @@ static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) #endif /* CONFIG_CGROUP_WRITEBACK */ /* - * DO NOT USE IN NEW FILES. - * - * "cgroup.event_control" implementation. - * - * This is way over-engineered. It tries to support fully configurable - * events for each user. Such level of flexibility is completely - * unnecessary especially in the light of the planned unified hierarchy. - * - * Please deprecate this and replace with something simpler if at all - * possible. - */ - -/* - * Unregister event and free resources. - * - * Gets called from workqueue. - */ -static void memcg_event_remove(struct work_struct *work) -{ - struct mem_cgroup_event *event = - container_of(work, struct mem_cgroup_event, remove); - struct mem_cgroup *memcg = event->memcg; - - remove_wait_queue(event->wqh, &event->wait); - - event->unregister_event(memcg, event->eventfd); - - /* Notify userspace the event is going away. */ - eventfd_signal(event->eventfd, 1); - - eventfd_ctx_put(event->eventfd); - kfree(event); - css_put(&memcg->css); -} - -/* - * Gets called on EPOLLHUP on eventfd when user closes it. - * - * Called with wqh->lock held and interrupts disabled. - */ -static int memcg_event_wake(wait_queue_entry_t *wait, unsigned mode, - int sync, void *key) -{ - struct mem_cgroup_event *event = - container_of(wait, struct mem_cgroup_event, wait); - struct mem_cgroup *memcg = event->memcg; - __poll_t flags = key_to_poll(key); - - if (flags & EPOLLHUP) { - /* - * If the event has been detached at cgroup removal, we - * can simply return knowing the other side will cleanup - * for us. - * - * We can't race against event freeing since the other - * side will require wqh->lock via remove_wait_queue(), - * which we hold. - */ - spin_lock(&memcg->event_list_lock); - if (!list_empty(&event->list)) { - list_del_init(&event->list); - /* - * We are in atomic context, but cgroup_event_remove() - * may sleep, so we have to call it in workqueue. - */ - schedule_work(&event->remove); - } - spin_unlock(&memcg->event_list_lock); - } - - return 0; -} - -static void memcg_event_ptable_queue_proc(struct file *file, - wait_queue_head_t *wqh, poll_table *pt) -{ - struct mem_cgroup_event *event = - container_of(pt, struct mem_cgroup_event, pt); - - event->wqh = wqh; - add_wait_queue(wqh, &event->wait); -} - -/* - * DO NOT USE IN NEW FILES. - * - * Parse input and register new cgroup event handler. - * - * Input must be in format '<event_fd> <control_fd> <args>'. - * Interpretation of args is defined by control file implementation. - */ -static ssize_t memcg_write_event_control(struct kernfs_open_file *of, - char *buf, size_t nbytes, loff_t off) -{ - struct cgroup_subsys_state *css = of_css(of); - struct mem_cgroup *memcg = mem_cgroup_from_css(css); - struct mem_cgroup_event *event; - struct cgroup_subsys_state *cfile_css; - unsigned int efd, cfd; - struct fd efile; - struct fd cfile; - struct dentry *cdentry; - const char *name; - char *endp; - int ret; - - if (IS_ENABLED(CONFIG_PREEMPT_RT)) - return -EOPNOTSUPP; - - buf = strstrip(buf); - - efd = simple_strtoul(buf, &endp, 10); - if (*endp != ' ') - return -EINVAL; - buf = endp + 1; - - cfd = simple_strtoul(buf, &endp, 10); - if ((*endp != ' ') && (*endp != '\0')) - return -EINVAL; - buf = endp + 1; - - event = kzalloc(sizeof(*event), GFP_KERNEL); - if (!event) - return -ENOMEM; - - event->memcg = memcg; - INIT_LIST_HEAD(&event->list); - init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc); - init_waitqueue_func_entry(&event->wait, memcg_event_wake); - INIT_WORK(&event->remove, memcg_event_remove); - - efile = fdget(efd); - if (!efile.file) { - ret = -EBADF; - goto out_kfree; - } - - event->eventfd = eventfd_ctx_fileget(efile.file); - if (IS_ERR(event->eventfd)) { - ret = PTR_ERR(event->eventfd); - goto out_put_efile; - } - - cfile = fdget(cfd); - if (!cfile.file) { - ret = -EBADF; - goto out_put_eventfd; - } - - /* the process need read permission on control file */ - /* AV: shouldn't we check that it's been opened for read instead? */ - ret = file_permission(cfile.file, MAY_READ); - if (ret < 0) - goto out_put_cfile; - - /* - * The control file must be a regular cgroup1 file. As a regular cgroup - * file can't be renamed, it's safe to access its name afterwards. - */ - cdentry = cfile.file->f_path.dentry; - if (cdentry->d_sb->s_type != &cgroup_fs_type || !d_is_reg(cdentry)) { - ret = -EINVAL; - goto out_put_cfile; - } - - /* - * Determine the event callbacks and set them in @event. This used - * to be done via struct cftype but cgroup core no longer knows - * about these events. The following is crude but the whole thing - * is for compatibility anyway. - * - * DO NOT ADD NEW FILES. - */ - name = cdentry->d_name.name; - - if (!strcmp(name, "memory.usage_in_bytes")) { - event->register_event = mem_cgroup_usage_register_event; - event->unregister_event = mem_cgroup_usage_unregister_event; - } else if (!strcmp(name, "memory.oom_control")) { - event->register_event = mem_cgroup_oom_register_event; - event->unregister_event = mem_cgroup_oom_unregister_event; - } else if (!strcmp(name, "memory.pressure_level")) { - event->register_event = vmpressure_register_event; - event->unregister_event = vmpressure_unregister_event; - } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) { - event->register_event = memsw_cgroup_usage_register_event; - event->unregister_event = memsw_cgroup_usage_unregister_event; - } else { - ret = -EINVAL; - goto out_put_cfile; - } - - /* - * Verify @cfile should belong to @css. Also, remaining events are - * automatically removed on cgroup destruction but the removal is - * asynchronous, so take an extra ref on @css. - */ - cfile_css = css_tryget_online_from_dir(cdentry->d_parent, - &memory_cgrp_subsys); - ret = -EINVAL; - if (IS_ERR(cfile_css)) - goto out_put_cfile; - if (cfile_css != css) { - css_put(cfile_css); - goto out_put_cfile; - } - - ret = event->register_event(memcg, event->eventfd, buf); - if (ret) - goto out_put_css; - - vfs_poll(efile.file, &event->pt); - - spin_lock_irq(&memcg->event_list_lock); - list_add(&event->list, &memcg->event_list); - spin_unlock_irq(&memcg->event_list_lock); - - fdput(cfile); - fdput(efile); - - return nbytes; - -out_put_css: - css_put(css); -out_put_cfile: - fdput(cfile); -out_put_eventfd: - eventfd_ctx_put(event->eventfd); -out_put_efile: - fdput(efile); -out_kfree: - kfree(event); - - return ret; -} - -#if defined(CONFIG_MEMCG_KMEM) && (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) -static int mem_cgroup_slab_show(struct seq_file *m, void *p) -{ - /* - * Deprecated. - * Please, take a look at tools/cgroup/memcg_slabinfo.py . - */ - return 0; -} -#endif - -static struct cftype mem_cgroup_legacy_files[] = { - { - .name = "usage_in_bytes", - .private = MEMFILE_PRIVATE(_MEM, RES_USAGE), - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "max_usage_in_bytes", - .private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE), - .write = mem_cgroup_reset, - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "limit_in_bytes", - .private = MEMFILE_PRIVATE(_MEM, RES_LIMIT), - .write = mem_cgroup_write, - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "soft_limit_in_bytes", - .private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT), - .write = mem_cgroup_write, - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "failcnt", - .private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT), - .write = mem_cgroup_reset, - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "stat", - .seq_show = memcg_stat_show, - }, - { - .name = "force_empty", - .write = mem_cgroup_force_empty_write, - }, - { - .name = "use_hierarchy", - .write_u64 = mem_cgroup_hierarchy_write, - .read_u64 = mem_cgroup_hierarchy_read, - }, - { - .name = "cgroup.event_control", /* XXX: for compat */ - .write = memcg_write_event_control, - .flags = CFTYPE_NO_PREFIX | CFTYPE_WORLD_WRITABLE, - }, - { - .name = "swappiness", - .read_u64 = mem_cgroup_swappiness_read, - .write_u64 = mem_cgroup_swappiness_write, - }, - { - .name = "move_charge_at_immigrate", - .read_u64 = mem_cgroup_move_charge_read, - .write_u64 = mem_cgroup_move_charge_write, - }, - { - .name = "oom_control", - .seq_show = mem_cgroup_oom_control_read, - .write_u64 = mem_cgroup_oom_control_write, - }, - { - .name = "pressure_level", - }, -#ifdef CONFIG_NUMA - { - .name = "numa_stat", - .seq_show = memcg_numa_stat_show, - }, -#endif - { - .name = "kmem.limit_in_bytes", - .private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT), - .write = mem_cgroup_write, - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "kmem.usage_in_bytes", - .private = MEMFILE_PRIVATE(_KMEM, RES_USAGE), - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "kmem.failcnt", - .private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT), - .write = mem_cgroup_reset, - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "kmem.max_usage_in_bytes", - .private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE), - .write = mem_cgroup_reset, - .read_u64 = mem_cgroup_read_u64, - }, -#if defined(CONFIG_MEMCG_KMEM) && \ - (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) - { - .name = "kmem.slabinfo", - .seq_show = mem_cgroup_slab_show, - }, -#endif - { - .name = "kmem.tcp.limit_in_bytes", - .private = MEMFILE_PRIVATE(_TCP, RES_LIMIT), - .write = mem_cgroup_write, - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "kmem.tcp.usage_in_bytes", - .private = MEMFILE_PRIVATE(_TCP, RES_USAGE), - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "kmem.tcp.failcnt", - .private = MEMFILE_PRIVATE(_TCP, RES_FAILCNT), - .write = mem_cgroup_reset, - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "kmem.tcp.max_usage_in_bytes", - .private = MEMFILE_PRIVATE(_TCP, RES_MAX_USAGE), - .write = mem_cgroup_reset, - .read_u64 = mem_cgroup_read_u64, - }, - { }, /* terminate */ -}; - -/* * Private memory cgroup IDR * * Swap-out records and page cache shadow entries need to store memcg @@ -5139,18 +3580,19 @@ static struct cftype mem_cgroup_legacy_files[] = { * those references are manageable from userspace. */ -static DEFINE_IDR(mem_cgroup_idr); +#define MEM_CGROUP_ID_MAX ((1UL << MEM_CGROUP_ID_SHIFT) - 1) +static DEFINE_XARRAY_ALLOC1(mem_cgroup_ids); static void mem_cgroup_id_remove(struct mem_cgroup *memcg) { if (memcg->id.id > 0) { - idr_remove(&mem_cgroup_idr, memcg->id.id); + xa_erase(&mem_cgroup_ids, memcg->id.id); memcg->id.id = 0; } } -static void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg, - unsigned int n) +void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg, + unsigned int n) { refcount_add(n, &memcg->id.ref); } @@ -5170,6 +3612,24 @@ static inline void mem_cgroup_id_put(struct mem_cgroup *memcg) mem_cgroup_id_put_many(memcg, 1); } +struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) +{ + while (!refcount_inc_not_zero(&memcg->id.ref)) { + /* + * The root cgroup cannot be destroyed, so it's refcount must + * always be >= 1. + */ + if (WARN_ON_ONCE(mem_cgroup_is_root(memcg))) { + VM_BUG_ON(1); + break; + } + memcg = parent_mem_cgroup(memcg); + if (!memcg) + memcg = root_mem_cgroup; + } + return memcg; +} + /** * mem_cgroup_from_id - look up a memcg from a memcg id * @id: the memcg id to look up @@ -5179,7 +3639,7 @@ static inline void mem_cgroup_id_put(struct mem_cgroup *memcg) struct mem_cgroup *mem_cgroup_from_id(unsigned short id) { WARN_ON_ONCE(!rcu_read_lock_held()); - return idr_find(&mem_cgroup_idr, id); + return xa_load(&mem_cgroup_ids, id); } #ifdef CONFIG_SHRINKER_DEBUG @@ -5205,45 +3665,54 @@ struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino) } #endif -static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) +static void free_mem_cgroup_per_node_info(struct mem_cgroup_per_node *pn) +{ + if (!pn) + return; + + free_percpu(pn->lruvec_stats_percpu); + kfree(pn->lruvec_stats); + kfree(pn); +} + +static bool alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) { struct mem_cgroup_per_node *pn; - pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, node); + pn = kmem_cache_alloc_node(memcg_pn_cachep, GFP_KERNEL | __GFP_ZERO, + node); if (!pn) - return 1; + return false; + + pn->lruvec_stats = kzalloc_node(sizeof(struct lruvec_stats), + GFP_KERNEL_ACCOUNT, node); + if (!pn->lruvec_stats) + goto fail; pn->lruvec_stats_percpu = alloc_percpu_gfp(struct lruvec_stats_percpu, GFP_KERNEL_ACCOUNT); - if (!pn->lruvec_stats_percpu) { - kfree(pn); - return 1; - } + if (!pn->lruvec_stats_percpu) + goto fail; lruvec_init(&pn->lruvec); pn->memcg = memcg; memcg->nodeinfo[node] = pn; - return 0; -} - -static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node) -{ - struct mem_cgroup_per_node *pn = memcg->nodeinfo[node]; - - if (!pn) - return; - - free_percpu(pn->lruvec_stats_percpu); - kfree(pn); + return true; +fail: + free_mem_cgroup_per_node_info(pn); + return false; } static void __mem_cgroup_free(struct mem_cgroup *memcg) { int node; + obj_cgroup_put(memcg->orig_objcg); + for_each_node(node) - free_mem_cgroup_per_node_info(memcg, node); + free_mem_cgroup_per_node_info(memcg->nodeinfo[node]); + memcg1_free_events(memcg); kfree(memcg->vmstats); free_percpu(memcg->vmstats_percpu); kfree(memcg); @@ -5256,25 +3725,27 @@ static void mem_cgroup_free(struct mem_cgroup *memcg) __mem_cgroup_free(memcg); } -static struct mem_cgroup *mem_cgroup_alloc(void) +static struct mem_cgroup *mem_cgroup_alloc(struct mem_cgroup *parent) { + struct memcg_vmstats_percpu *statc; + struct memcg_vmstats_percpu __percpu *pstatc_pcpu; struct mem_cgroup *memcg; - int node; + int node, cpu; int __maybe_unused i; - long error = -ENOMEM; + long error; - memcg = kzalloc(struct_size(memcg, nodeinfo, nr_node_ids), GFP_KERNEL); + memcg = kmem_cache_zalloc(memcg_cachep, GFP_KERNEL); if (!memcg) - return ERR_PTR(error); + return ERR_PTR(-ENOMEM); - memcg->id.id = idr_alloc(&mem_cgroup_idr, NULL, - 1, MEM_CGROUP_ID_MAX + 1, GFP_KERNEL); - if (memcg->id.id < 0) { - error = memcg->id.id; + error = xa_alloc(&mem_cgroup_ids, &memcg->id.id, NULL, + XA_LIMIT(1, MEM_CGROUP_ID_MAX), GFP_KERNEL); + if (error) goto fail; - } + error = -ENOMEM; - memcg->vmstats = kzalloc(sizeof(struct memcg_vmstats), GFP_KERNEL); + memcg->vmstats = kzalloc(sizeof(struct memcg_vmstats), + GFP_KERNEL_ACCOUNT); if (!memcg->vmstats) goto fail; @@ -5283,25 +3754,36 @@ static struct mem_cgroup *mem_cgroup_alloc(void) if (!memcg->vmstats_percpu) goto fail; + if (!memcg1_alloc_events(memcg)) + goto fail; + + for_each_possible_cpu(cpu) { + if (parent) + pstatc_pcpu = parent->vmstats_percpu; + statc = per_cpu_ptr(memcg->vmstats_percpu, cpu); + statc->parent_pcpu = parent ? pstatc_pcpu : NULL; + statc->vmstats = memcg->vmstats; + } + for_each_node(node) - if (alloc_mem_cgroup_per_node_info(memcg, node)) + if (!alloc_mem_cgroup_per_node_info(memcg, node)) goto fail; if (memcg_wb_domain_init(memcg, GFP_KERNEL)) goto fail; INIT_WORK(&memcg->high_work, high_work_func); - INIT_LIST_HEAD(&memcg->oom_notify); - mutex_init(&memcg->thresholds_lock); - spin_lock_init(&memcg->move_lock); vmpressure_init(&memcg->vmpressure); - INIT_LIST_HEAD(&memcg->event_list); - spin_lock_init(&memcg->event_list_lock); - memcg->socket_pressure = jiffies; -#ifdef CONFIG_MEMCG_KMEM + INIT_LIST_HEAD(&memcg->memory_peaks); + INIT_LIST_HEAD(&memcg->swap_peaks); + spin_lock_init(&memcg->peaks_lock); + memcg->socket_pressure = get_jiffies_64(); +#if BITS_PER_LONG < 64 + seqlock_init(&memcg->socket_pressure_seqlock); +#endif + memcg1_memcg_init(memcg); memcg->kmemcg_id = -1; INIT_LIST_HEAD(&memcg->objcg_list); -#endif #ifdef CONFIG_CGROUP_WRITEBACK INIT_LIST_HEAD(&memcg->cgwb_list); for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) @@ -5313,7 +3795,6 @@ static struct mem_cgroup *mem_cgroup_alloc(void) INIT_LIST_HEAD(&memcg->deferred_split_queue.split_queue); memcg->deferred_split_queue.split_queue_len = 0; #endif - idr_replace(&mem_cgroup_idr, memcg, memcg->id.id); lru_gen_init_memcg(memcg); return memcg; fail: @@ -5327,41 +3808,51 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) { struct mem_cgroup *parent = mem_cgroup_from_css(parent_css); struct mem_cgroup *memcg, *old_memcg; + bool memcg_on_dfl = cgroup_subsys_on_dfl(memory_cgrp_subsys); old_memcg = set_active_memcg(parent); - memcg = mem_cgroup_alloc(); + memcg = mem_cgroup_alloc(parent); set_active_memcg(old_memcg); if (IS_ERR(memcg)) return ERR_CAST(memcg); page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX); - memcg->soft_limit = PAGE_COUNTER_MAX; -#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) + memcg1_soft_limit_reset(memcg); +#ifdef CONFIG_ZSWAP memcg->zswap_max = PAGE_COUNTER_MAX; + WRITE_ONCE(memcg->zswap_writeback, true); #endif page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); if (parent) { - memcg->swappiness = mem_cgroup_swappiness(parent); - memcg->oom_kill_disable = parent->oom_kill_disable; - - page_counter_init(&memcg->memory, &parent->memory); - page_counter_init(&memcg->swap, &parent->swap); - page_counter_init(&memcg->kmem, &parent->kmem); - page_counter_init(&memcg->tcpmem, &parent->tcpmem); + WRITE_ONCE(memcg->swappiness, mem_cgroup_swappiness(parent)); + + page_counter_init(&memcg->memory, &parent->memory, memcg_on_dfl); + page_counter_init(&memcg->swap, &parent->swap, false); +#ifdef CONFIG_MEMCG_V1 + memcg->memory.track_failcnt = !memcg_on_dfl; + WRITE_ONCE(memcg->oom_kill_disable, READ_ONCE(parent->oom_kill_disable)); + page_counter_init(&memcg->kmem, &parent->kmem, false); + page_counter_init(&memcg->tcpmem, &parent->tcpmem, false); +#endif } else { + init_memcg_stats(); init_memcg_events(); - page_counter_init(&memcg->memory, NULL); - page_counter_init(&memcg->swap, NULL); - page_counter_init(&memcg->kmem, NULL); - page_counter_init(&memcg->tcpmem, NULL); - + page_counter_init(&memcg->memory, NULL, true); + page_counter_init(&memcg->swap, NULL, false); +#ifdef CONFIG_MEMCG_V1 + page_counter_init(&memcg->kmem, NULL, false); + page_counter_init(&memcg->tcpmem, NULL, false); +#endif root_mem_cgroup = memcg; return &memcg->css; } - if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) + if (memcg_on_dfl && !cgroup_memory_nosocket) static_branch_inc(&memcg_sockets_enabled_key); + if (!cgroup_memory_nobpf) + static_branch_inc(&memcg_bpf_enabled_key); + return &memcg->css; } @@ -5380,13 +3871,27 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css) if (alloc_shrinker_info(memcg)) goto offline_kmem; + if (unlikely(mem_cgroup_is_root(memcg)) && !mem_cgroup_disabled()) + queue_delayed_work(system_unbound_wq, &stats_flush_dwork, + FLUSH_TIME); + lru_gen_online_memcg(memcg); + /* Online state pins memcg ID, memcg ID pins CSS */ refcount_set(&memcg->id.ref, 1); css_get(css); - if (unlikely(mem_cgroup_is_root(memcg))) - queue_delayed_work(system_unbound_wq, &stats_flush_dwork, - 2UL*HZ); + /* + * Ensure mem_cgroup_from_id() works once we're fully online. + * + * We could do this earlier and require callers to filter with + * css_tryget_online(). But right now there are no users that + * need earlier access, and the workingset code relies on the + * cgroup tree linkage (mem_cgroup_get_nr_swap_pages()). So + * publish it here at the end of onlining. This matches the + * regular ID destruction during offlining. + */ + xa_store(&mem_cgroup_ids, memcg->id.id, memcg, GFP_KERNEL); + return 0; offline_kmem: memcg_offline_kmem(memcg); @@ -5398,26 +3903,19 @@ remove_id: static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) { struct mem_cgroup *memcg = mem_cgroup_from_css(css); - struct mem_cgroup_event *event, *tmp; - /* - * Unregister events and notify userspace. - * Notify userspace about cgroup removing only after rmdir of cgroup - * directory to avoid race between userspace and kernelspace. - */ - spin_lock_irq(&memcg->event_list_lock); - list_for_each_entry_safe(event, tmp, &memcg->event_list, list) { - list_del_init(&event->list); - schedule_work(&event->remove); - } - spin_unlock_irq(&memcg->event_list_lock); + memcg1_css_offline(memcg); page_counter_set_min(&memcg->memory, 0); page_counter_set_low(&memcg->memory, 0); + zswap_memcg_offline_cleanup(memcg); + memcg_offline_kmem(memcg); + reparent_deferred_split_queue(memcg); reparent_shrinker_deferred(memcg); wb_memcg_offline(memcg); + lru_gen_offline_memcg(memcg); drain_all_stock(memcg); @@ -5429,6 +3927,7 @@ static void mem_cgroup_css_released(struct cgroup_subsys_state *css) struct mem_cgroup *memcg = mem_cgroup_from_css(css); invalidate_reclaim_iterators(memcg); + lru_gen_release_memcg(memcg); } static void mem_cgroup_css_free(struct cgroup_subsys_state *css) @@ -5443,12 +3942,15 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) static_branch_dec(&memcg_sockets_enabled_key); - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_active) + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg1_tcpmem_active(memcg)) static_branch_dec(&memcg_sockets_enabled_key); + if (!cgroup_memory_nobpf) + static_branch_dec(&memcg_bpf_enabled_key); + vmpressure_cleanup(&memcg->vmpressure); cancel_work_sync(&memcg->high_work); - mem_cgroup_remove_from_trees(memcg); + memcg1_remove_from_trees(memcg); free_shrinker_info(memcg); mem_cgroup_free(memcg); } @@ -5472,878 +3974,351 @@ static void mem_cgroup_css_reset(struct cgroup_subsys_state *css) page_counter_set_max(&memcg->memory, PAGE_COUNTER_MAX); page_counter_set_max(&memcg->swap, PAGE_COUNTER_MAX); +#ifdef CONFIG_MEMCG_V1 page_counter_set_max(&memcg->kmem, PAGE_COUNTER_MAX); page_counter_set_max(&memcg->tcpmem, PAGE_COUNTER_MAX); +#endif page_counter_set_min(&memcg->memory, 0); page_counter_set_low(&memcg->memory, 0); page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX); - memcg->soft_limit = PAGE_COUNTER_MAX; + memcg1_soft_limit_reset(memcg); page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); memcg_wb_domain_size_changed(memcg); } -static void mem_cgroup_css_rstat_flush(struct cgroup_subsys_state *css, int cpu) -{ - struct mem_cgroup *memcg = mem_cgroup_from_css(css); - struct mem_cgroup *parent = parent_mem_cgroup(memcg); - struct memcg_vmstats_percpu *statc; - long delta, v; - int i, nid; +struct aggregate_control { + /* pointer to the aggregated (CPU and subtree aggregated) counters */ + long *aggregate; + /* pointer to the non-hierarchichal (CPU aggregated) counters */ + long *local; + /* pointer to the pending child counters during tree propagation */ + long *pending; + /* pointer to the parent's pending counters, could be NULL */ + long *ppending; + /* pointer to the percpu counters to be aggregated */ + long *cstat; + /* pointer to the percpu counters of the last aggregation*/ + long *cstat_prev; + /* size of the above counters */ + int size; +}; - statc = per_cpu_ptr(memcg->vmstats_percpu, cpu); +static void mem_cgroup_stat_aggregate(struct aggregate_control *ac) +{ + int i; + long delta, delta_cpu, v; - for (i = 0; i < MEMCG_NR_STAT; i++) { + for (i = 0; i < ac->size; i++) { /* * Collect the aggregated propagation counts of groups * below us. We're in a per-cpu loop here and this is * a global counter, so the first cycle will get them. */ - delta = memcg->vmstats->state_pending[i]; + delta = ac->pending[i]; if (delta) - memcg->vmstats->state_pending[i] = 0; + ac->pending[i] = 0; /* Add CPU changes on this level since the last flush */ - v = READ_ONCE(statc->state[i]); - if (v != statc->state_prev[i]) { - delta += v - statc->state_prev[i]; - statc->state_prev[i] = v; + delta_cpu = 0; + v = READ_ONCE(ac->cstat[i]); + if (v != ac->cstat_prev[i]) { + delta_cpu = v - ac->cstat_prev[i]; + delta += delta_cpu; + ac->cstat_prev[i] = v; } - if (!delta) - continue; - /* Aggregate counts on this level and propagate upwards */ - memcg->vmstats->state[i] += delta; - if (parent) - parent->vmstats->state_pending[i] += delta; - } - - for (i = 0; i < NR_MEMCG_EVENTS; i++) { - delta = memcg->vmstats->events_pending[i]; - if (delta) - memcg->vmstats->events_pending[i] = 0; + if (delta_cpu) + ac->local[i] += delta_cpu; - v = READ_ONCE(statc->events[i]); - if (v != statc->events_prev[i]) { - delta += v - statc->events_prev[i]; - statc->events_prev[i] = v; + if (delta) { + ac->aggregate[i] += delta; + if (ac->ppending) + ac->ppending[i] += delta; } + } +} - if (!delta) - continue; +#ifdef CONFIG_MEMCG_NMI_SAFETY_REQUIRES_ATOMIC +static void flush_nmi_stats(struct mem_cgroup *memcg, struct mem_cgroup *parent, + int cpu) +{ + int nid; + + if (atomic_read(&memcg->kmem_stat)) { + int kmem = atomic_xchg(&memcg->kmem_stat, 0); + int index = memcg_stats_index(MEMCG_KMEM); - memcg->vmstats->events[i] += delta; + memcg->vmstats->state[index] += kmem; if (parent) - parent->vmstats->events_pending[i] += delta; + parent->vmstats->state_pending[index] += kmem; } for_each_node_state(nid, N_MEMORY) { struct mem_cgroup_per_node *pn = memcg->nodeinfo[nid]; - struct mem_cgroup_per_node *ppn = NULL; - struct lruvec_stats_percpu *lstatc; + struct lruvec_stats *lstats = pn->lruvec_stats; + struct lruvec_stats *plstats = NULL; if (parent) - ppn = parent->nodeinfo[nid]; - - lstatc = per_cpu_ptr(pn->lruvec_stats_percpu, cpu); + plstats = parent->nodeinfo[nid]->lruvec_stats; - for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { - delta = pn->lruvec_stats.state_pending[i]; - if (delta) - pn->lruvec_stats.state_pending[i] = 0; + if (atomic_read(&pn->slab_reclaimable)) { + int slab = atomic_xchg(&pn->slab_reclaimable, 0); + int index = memcg_stats_index(NR_SLAB_RECLAIMABLE_B); - v = READ_ONCE(lstatc->state[i]); - if (v != lstatc->state_prev[i]) { - delta += v - lstatc->state_prev[i]; - lstatc->state_prev[i] = v; - } - - if (!delta) - continue; - - pn->lruvec_stats.state[i] += delta; - if (ppn) - ppn->lruvec_stats.state_pending[i] += delta; + lstats->state[index] += slab; + if (plstats) + plstats->state_pending[index] += slab; } - } -} - -#ifdef CONFIG_MMU -/* Handlers for move charge at task migration. */ -static int mem_cgroup_do_precharge(unsigned long count) -{ - int ret; - - /* Try a single bulk charge without reclaim first, kswapd may wake */ - ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_DIRECT_RECLAIM, count); - if (!ret) { - mc.precharge += count; - return ret; - } - - /* Try charges one by one with reclaim, but do not retry */ - while (count--) { - ret = try_charge(mc.to, GFP_KERNEL | __GFP_NORETRY, 1); - if (ret) - return ret; - mc.precharge++; - cond_resched(); - } - return 0; -} - -union mc_target { - struct page *page; - swp_entry_t ent; -}; - -enum mc_target_type { - MC_TARGET_NONE = 0, - MC_TARGET_PAGE, - MC_TARGET_SWAP, - MC_TARGET_DEVICE, -}; - -static struct page *mc_handle_present_pte(struct vm_area_struct *vma, - unsigned long addr, pte_t ptent) -{ - struct page *page = vm_normal_page(vma, addr, ptent); - - if (!page || !page_mapped(page)) - return NULL; - if (PageAnon(page)) { - if (!(mc.flags & MOVE_ANON)) - return NULL; - } else { - if (!(mc.flags & MOVE_FILE)) - return NULL; - } - if (!get_page_unless_zero(page)) - return NULL; + if (atomic_read(&pn->slab_unreclaimable)) { + int slab = atomic_xchg(&pn->slab_unreclaimable, 0); + int index = memcg_stats_index(NR_SLAB_UNRECLAIMABLE_B); - return page; -} - -#if defined(CONFIG_SWAP) || defined(CONFIG_DEVICE_PRIVATE) -static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, - pte_t ptent, swp_entry_t *entry) -{ - struct page *page = NULL; - swp_entry_t ent = pte_to_swp_entry(ptent); - - if (!(mc.flags & MOVE_ANON)) - return NULL; - - /* - * Handle device private pages that are not accessible by the CPU, but - * stored as special swap entries in the page table. - */ - if (is_device_private_entry(ent)) { - page = pfn_swap_entry_to_page(ent); - if (!get_page_unless_zero(page)) - return NULL; - return page; + lstats->state[index] += slab; + if (plstats) + plstats->state_pending[index] += slab; + } } - - if (non_swap_entry(ent)) - return NULL; - - /* - * Because swap_cache_get_folio() updates some statistics counter, - * we call find_get_page() with swapper_space directly. - */ - page = find_get_page(swap_address_space(ent), swp_offset(ent)); - entry->val = ent.val; - - return page; } #else -static struct page *mc_handle_swap_pte(struct vm_area_struct *vma, - pte_t ptent, swp_entry_t *entry) -{ - return NULL; -} +static void flush_nmi_stats(struct mem_cgroup *memcg, struct mem_cgroup *parent, + int cpu) +{} #endif -static struct page *mc_handle_file_pte(struct vm_area_struct *vma, - unsigned long addr, pte_t ptent) +static void mem_cgroup_css_rstat_flush(struct cgroup_subsys_state *css, int cpu) { - unsigned long index; - struct folio *folio; - - if (!vma->vm_file) /* anonymous vma */ - return NULL; - if (!(mc.flags & MOVE_FILE)) - return NULL; - - /* folio is moved even if it's not RSS of this task(page-faulted). */ - /* shmem/tmpfs may report page out on swap: account for that too. */ - index = linear_page_index(vma, addr); - folio = filemap_get_incore_folio(vma->vm_file->f_mapping, index); - if (!folio) - return NULL; - return folio_file_page(folio, index); -} + struct mem_cgroup *memcg = mem_cgroup_from_css(css); + struct mem_cgroup *parent = parent_mem_cgroup(memcg); + struct memcg_vmstats_percpu *statc; + struct aggregate_control ac; + int nid; -/** - * mem_cgroup_move_account - move account of the page - * @page: the page - * @compound: charge the page as compound or small page - * @from: mem_cgroup which the page is moved from. - * @to: mem_cgroup which the page is moved to. @from != @to. - * - * The caller must make sure the page is not on LRU (isolate_page() is useful.) - * - * This function doesn't do "charge" to new cgroup and doesn't do "uncharge" - * from old cgroup. - */ -static int mem_cgroup_move_account(struct page *page, - bool compound, - struct mem_cgroup *from, - struct mem_cgroup *to) -{ - struct folio *folio = page_folio(page); - struct lruvec *from_vec, *to_vec; - struct pglist_data *pgdat; - unsigned int nr_pages = compound ? folio_nr_pages(folio) : 1; - int nid, ret; - - VM_BUG_ON(from == to); - VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); - VM_BUG_ON(compound && !folio_test_large(folio)); + flush_nmi_stats(memcg, parent, cpu); - /* - * Prevent mem_cgroup_migrate() from looking at - * page's memory cgroup of its source page while we change it. - */ - ret = -EBUSY; - if (!folio_trylock(folio)) - goto out; + statc = per_cpu_ptr(memcg->vmstats_percpu, cpu); - ret = -EINVAL; - if (folio_memcg(folio) != from) - goto out_unlock; - - pgdat = folio_pgdat(folio); - from_vec = mem_cgroup_lruvec(from, pgdat); - to_vec = mem_cgroup_lruvec(to, pgdat); - - folio_memcg_lock(folio); - - if (folio_test_anon(folio)) { - if (folio_mapped(folio)) { - __mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages); - __mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages); - if (folio_test_transhuge(folio)) { - __mod_lruvec_state(from_vec, NR_ANON_THPS, - -nr_pages); - __mod_lruvec_state(to_vec, NR_ANON_THPS, - nr_pages); - } - } - } else { - __mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages); - __mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages); + ac = (struct aggregate_control) { + .aggregate = memcg->vmstats->state, + .local = memcg->vmstats->state_local, + .pending = memcg->vmstats->state_pending, + .ppending = parent ? parent->vmstats->state_pending : NULL, + .cstat = statc->state, + .cstat_prev = statc->state_prev, + .size = MEMCG_VMSTAT_SIZE, + }; + mem_cgroup_stat_aggregate(&ac); + + ac = (struct aggregate_control) { + .aggregate = memcg->vmstats->events, + .local = memcg->vmstats->events_local, + .pending = memcg->vmstats->events_pending, + .ppending = parent ? parent->vmstats->events_pending : NULL, + .cstat = statc->events, + .cstat_prev = statc->events_prev, + .size = NR_MEMCG_EVENTS, + }; + mem_cgroup_stat_aggregate(&ac); - if (folio_test_swapbacked(folio)) { - __mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages); - __mod_lruvec_state(to_vec, NR_SHMEM, nr_pages); - } + for_each_node_state(nid, N_MEMORY) { + struct mem_cgroup_per_node *pn = memcg->nodeinfo[nid]; + struct lruvec_stats *lstats = pn->lruvec_stats; + struct lruvec_stats *plstats = NULL; + struct lruvec_stats_percpu *lstatc; - if (folio_mapped(folio)) { - __mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages); - __mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages); - } + if (parent) + plstats = parent->nodeinfo[nid]->lruvec_stats; - if (folio_test_dirty(folio)) { - struct address_space *mapping = folio_mapping(folio); + lstatc = per_cpu_ptr(pn->lruvec_stats_percpu, cpu); - if (mapping_can_writeback(mapping)) { - __mod_lruvec_state(from_vec, NR_FILE_DIRTY, - -nr_pages); - __mod_lruvec_state(to_vec, NR_FILE_DIRTY, - nr_pages); - } - } - } + ac = (struct aggregate_control) { + .aggregate = lstats->state, + .local = lstats->state_local, + .pending = lstats->state_pending, + .ppending = plstats ? plstats->state_pending : NULL, + .cstat = lstatc->state, + .cstat_prev = lstatc->state_prev, + .size = NR_MEMCG_NODE_STAT_ITEMS, + }; + mem_cgroup_stat_aggregate(&ac); -#ifdef CONFIG_SWAP - if (folio_test_swapcache(folio)) { - __mod_lruvec_state(from_vec, NR_SWAPCACHE, -nr_pages); - __mod_lruvec_state(to_vec, NR_SWAPCACHE, nr_pages); - } -#endif - if (folio_test_writeback(folio)) { - __mod_lruvec_state(from_vec, NR_WRITEBACK, -nr_pages); - __mod_lruvec_state(to_vec, NR_WRITEBACK, nr_pages); } + WRITE_ONCE(statc->stats_updates, 0); + /* We are in a per-cpu loop here, only do the atomic write once */ + if (atomic_read(&memcg->vmstats->stats_updates)) + atomic_set(&memcg->vmstats->stats_updates, 0); +} +static void mem_cgroup_fork(struct task_struct *task) +{ /* - * All state has been migrated, let's switch to the new memcg. - * - * It is safe to change page's memcg here because the page - * is referenced, charged, isolated, and locked: we can't race - * with (un)charging, migration, LRU putback, or anything else - * that would rely on a stable page's memory cgroup. - * - * Note that lock_page_memcg is a memcg lock, not a page lock, - * to save space. As soon as we switch page's memory cgroup to a - * new memcg that isn't locked, the above state can change - * concurrently again. Make sure we're truly done with it. + * Set the update flag to cause task->objcg to be initialized lazily + * on the first allocation. It can be done without any synchronization + * because it's always performed on the current task, so does + * current_objcg_update(). */ - smp_mb(); - - css_get(&to->css); - css_put(&from->css); - - folio->memcg_data = (unsigned long)to; - - __folio_memcg_unlock(from); - - ret = 0; - nid = folio_nid(folio); - - local_irq_disable(); - mem_cgroup_charge_statistics(to, nr_pages); - memcg_check_events(to, nid); - mem_cgroup_charge_statistics(from, -nr_pages); - memcg_check_events(from, nid); - local_irq_enable(); -out_unlock: - folio_unlock(folio); -out: - return ret; + task->objcg = (struct obj_cgroup *)CURRENT_OBJCG_UPDATE_FLAG; } -/** - * get_mctgt_type - get target type of moving charge - * @vma: the vma the pte to be checked belongs - * @addr: the address corresponding to the pte to be checked - * @ptent: the pte to be checked - * @target: the pointer the target page or swap ent will be stored(can be NULL) - * - * Returns - * 0(MC_TARGET_NONE): if the pte is not a target for move charge. - * 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for - * move charge. if @target is not NULL, the page is stored in target->page - * with extra refcnt got(Callers should handle it). - * 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a - * target for charge migration. if @target is not NULL, the entry is stored - * in target->ent. - * 3(MC_TARGET_DEVICE): like MC_TARGET_PAGE but page is device memory and - * thus not on the lru. - * For now we such page is charge like a regular page would be as for all - * intent and purposes it is just special memory taking the place of a - * regular page. - * - * See Documentations/vm/hmm.txt and include/linux/hmm.h - * - * Called with pte lock held. - */ - -static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma, - unsigned long addr, pte_t ptent, union mc_target *target) +static void mem_cgroup_exit(struct task_struct *task) { - struct page *page = NULL; - enum mc_target_type ret = MC_TARGET_NONE; - swp_entry_t ent = { .val = 0 }; + struct obj_cgroup *objcg = task->objcg; - if (pte_present(ptent)) - page = mc_handle_present_pte(vma, addr, ptent); - else if (pte_none_mostly(ptent)) - /* - * PTE markers should be treated as a none pte here, separated - * from other swap handling below. - */ - page = mc_handle_file_pte(vma, addr, ptent); - else if (is_swap_pte(ptent)) - page = mc_handle_swap_pte(vma, ptent, &ent); + objcg = (struct obj_cgroup *) + ((unsigned long)objcg & ~CURRENT_OBJCG_UPDATE_FLAG); + obj_cgroup_put(objcg); - if (!page && !ent.val) - return ret; - if (page) { - /* - * Do only loose check w/o serialization. - * mem_cgroup_move_account() checks the page is valid or - * not under LRU exclusion. - */ - if (page_memcg(page) == mc.from) { - ret = MC_TARGET_PAGE; - if (is_device_private_page(page) || - is_device_coherent_page(page)) - ret = MC_TARGET_DEVICE; - if (target) - target->page = page; - } - if (!ret || !target) - put_page(page); - } /* - * There is a swap entry and a page doesn't exist or isn't charged. - * But we cannot move a tail-page in a THP. + * Some kernel allocations can happen after this point, + * but let's ignore them. It can be done without any synchronization + * because it's always performed on the current task, so does + * current_objcg_update(). */ - if (ent.val && !ret && (!page || !PageTransCompound(page)) && - mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) { - ret = MC_TARGET_SWAP; - if (target) - target->ent = ent; - } - return ret; + task->objcg = NULL; } -#ifdef CONFIG_TRANSPARENT_HUGEPAGE -/* - * We don't consider PMD mapped swapping or file mapped pages because THP does - * not support them for now. - * Caller should make sure that pmd_trans_huge(pmd) is true. - */ -static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, - unsigned long addr, pmd_t pmd, union mc_target *target) +#ifdef CONFIG_LRU_GEN +static void mem_cgroup_lru_gen_attach(struct cgroup_taskset *tset) { - struct page *page = NULL; - enum mc_target_type ret = MC_TARGET_NONE; + struct task_struct *task; + struct cgroup_subsys_state *css; - if (unlikely(is_swap_pmd(pmd))) { - VM_BUG_ON(thp_migration_supported() && - !is_pmd_migration_entry(pmd)); - return ret; - } - page = pmd_page(pmd); - VM_BUG_ON_PAGE(!page || !PageHead(page), page); - if (!(mc.flags & MOVE_ANON)) - return ret; - if (page_memcg(page) == mc.from) { - ret = MC_TARGET_PAGE; - if (target) { - get_page(page); - target->page = page; - } - } - return ret; + /* find the first leader if there is any */ + cgroup_taskset_for_each_leader(task, css, tset) + break; + + if (!task) + return; + + task_lock(task); + if (task->mm && READ_ONCE(task->mm->owner) == task) + lru_gen_migrate_mm(task->mm); + task_unlock(task); } #else -static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma, - unsigned long addr, pmd_t pmd, union mc_target *target) -{ - return MC_TARGET_NONE; -} -#endif +static void mem_cgroup_lru_gen_attach(struct cgroup_taskset *tset) {} +#endif /* CONFIG_LRU_GEN */ -static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, - unsigned long addr, unsigned long end, - struct mm_walk *walk) +static void mem_cgroup_kmem_attach(struct cgroup_taskset *tset) { - struct vm_area_struct *vma = walk->vma; - pte_t *pte; - spinlock_t *ptl; + struct task_struct *task; + struct cgroup_subsys_state *css; - ptl = pmd_trans_huge_lock(pmd, vma); - if (ptl) { - /* - * Note their can not be MC_TARGET_DEVICE for now as we do not - * support transparent huge page with MEMORY_DEVICE_PRIVATE but - * this might change. - */ - if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) - mc.precharge += HPAGE_PMD_NR; - spin_unlock(ptl); - return 0; + cgroup_taskset_for_each(task, css, tset) { + /* atomically set the update bit */ + set_bit(CURRENT_OBJCG_UPDATE_BIT, (unsigned long *)&task->objcg); } - - if (pmd_trans_unstable(pmd)) - return 0; - pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); - for (; addr != end; pte++, addr += PAGE_SIZE) - if (get_mctgt_type(vma, addr, *pte, NULL)) - mc.precharge++; /* increment precharge temporarily */ - pte_unmap_unlock(pte - 1, ptl); - cond_resched(); - - return 0; } -static const struct mm_walk_ops precharge_walk_ops = { - .pmd_entry = mem_cgroup_count_precharge_pte_range, -}; - -static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm) +static void mem_cgroup_attach(struct cgroup_taskset *tset) { - unsigned long precharge; - - mmap_read_lock(mm); - walk_page_range(mm, 0, ULONG_MAX, &precharge_walk_ops, NULL); - mmap_read_unlock(mm); - - precharge = mc.precharge; - mc.precharge = 0; - - return precharge; + mem_cgroup_lru_gen_attach(tset); + mem_cgroup_kmem_attach(tset); } -static int mem_cgroup_precharge_mc(struct mm_struct *mm) +static int seq_puts_memcg_tunable(struct seq_file *m, unsigned long value) { - unsigned long precharge = mem_cgroup_count_precharge(mm); + if (value == PAGE_COUNTER_MAX) + seq_puts(m, "max\n"); + else + seq_printf(m, "%llu\n", (u64)value * PAGE_SIZE); - VM_BUG_ON(mc.moving_task); - mc.moving_task = current; - return mem_cgroup_do_precharge(precharge); + return 0; } -/* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */ -static void __mem_cgroup_clear_mc(void) +static u64 memory_current_read(struct cgroup_subsys_state *css, + struct cftype *cft) { - struct mem_cgroup *from = mc.from; - struct mem_cgroup *to = mc.to; - - /* we must uncharge all the leftover precharges from mc.to */ - if (mc.precharge) { - cancel_charge(mc.to, mc.precharge); - mc.precharge = 0; - } - /* - * we didn't uncharge from mc.from at mem_cgroup_move_account(), so - * we must uncharge here. - */ - if (mc.moved_charge) { - cancel_charge(mc.from, mc.moved_charge); - mc.moved_charge = 0; - } - /* we must fixup refcnts and charges */ - if (mc.moved_swap) { - /* uncharge swap account from the old cgroup */ - if (!mem_cgroup_is_root(mc.from)) - page_counter_uncharge(&mc.from->memsw, mc.moved_swap); - - mem_cgroup_id_put_many(mc.from, mc.moved_swap); - - /* - * we charged both to->memory and to->memsw, so we - * should uncharge to->memory. - */ - if (!mem_cgroup_is_root(mc.to)) - page_counter_uncharge(&mc.to->memory, mc.moved_swap); + struct mem_cgroup *memcg = mem_cgroup_from_css(css); - mc.moved_swap = 0; - } - memcg_oom_recover(from); - memcg_oom_recover(to); - wake_up_all(&mc.waitq); + return (u64)page_counter_read(&memcg->memory) * PAGE_SIZE; } -static void mem_cgroup_clear_mc(void) +#define OFP_PEAK_UNSET (((-1UL))) + +static int peak_show(struct seq_file *sf, void *v, struct page_counter *pc) { - struct mm_struct *mm = mc.mm; + struct cgroup_of_peak *ofp = of_peak(sf->private); + u64 fd_peak = READ_ONCE(ofp->value), peak; - /* - * we must clear moving_task before waking up waiters at the end of - * task migration. - */ - mc.moving_task = NULL; - __mem_cgroup_clear_mc(); - spin_lock(&mc.lock); - mc.from = NULL; - mc.to = NULL; - mc.mm = NULL; - spin_unlock(&mc.lock); + /* User wants global or local peak? */ + if (fd_peak == OFP_PEAK_UNSET) + peak = pc->watermark; + else + peak = max(fd_peak, READ_ONCE(pc->local_watermark)); - mmput(mm); + seq_printf(sf, "%llu\n", peak * PAGE_SIZE); + return 0; } -static int mem_cgroup_can_attach(struct cgroup_taskset *tset) +static int memory_peak_show(struct seq_file *sf, void *v) { - struct cgroup_subsys_state *css; - struct mem_cgroup *memcg = NULL; /* unneeded init to make gcc happy */ - struct mem_cgroup *from; - struct task_struct *leader, *p; - struct mm_struct *mm; - unsigned long move_flags; - int ret = 0; - - /* charge immigration isn't supported on the default hierarchy */ - if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) - return 0; - - /* - * Multi-process migrations only happen on the default hierarchy - * where charge immigration is not used. Perform charge - * immigration if @tset contains a leader and whine if there are - * multiple. - */ - p = NULL; - cgroup_taskset_for_each_leader(leader, css, tset) { - WARN_ON_ONCE(p); - p = leader; - memcg = mem_cgroup_from_css(css); - } - if (!p) - return 0; - - /* - * We are now committed to this value whatever it is. Changes in this - * tunable will only affect upcoming migrations, not the current one. - * So we need to save it, and keep it going. - */ - move_flags = READ_ONCE(memcg->move_charge_at_immigrate); - if (!move_flags) - return 0; - - from = mem_cgroup_from_task(p); - - VM_BUG_ON(from == memcg); + struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf)); - mm = get_task_mm(p); - if (!mm) - return 0; - /* We move charges only when we move a owner of the mm */ - if (mm->owner == p) { - VM_BUG_ON(mc.from); - VM_BUG_ON(mc.to); - VM_BUG_ON(mc.precharge); - VM_BUG_ON(mc.moved_charge); - VM_BUG_ON(mc.moved_swap); - - spin_lock(&mc.lock); - mc.mm = mm; - mc.from = from; - mc.to = memcg; - mc.flags = move_flags; - spin_unlock(&mc.lock); - /* We set mc.moving_task later */ - - ret = mem_cgroup_precharge_mc(mm); - if (ret) - mem_cgroup_clear_mc(); - } else { - mmput(mm); - } - return ret; + return peak_show(sf, v, &memcg->memory); } -static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset) +static int peak_open(struct kernfs_open_file *of) { - if (mc.to) - mem_cgroup_clear_mc(); -} + struct cgroup_of_peak *ofp = of_peak(of); -static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, - unsigned long addr, unsigned long end, - struct mm_walk *walk) -{ - int ret = 0; - struct vm_area_struct *vma = walk->vma; - pte_t *pte; - spinlock_t *ptl; - enum mc_target_type target_type; - union mc_target target; - struct page *page; - - ptl = pmd_trans_huge_lock(pmd, vma); - if (ptl) { - if (mc.precharge < HPAGE_PMD_NR) { - spin_unlock(ptl); - return 0; - } - target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); - if (target_type == MC_TARGET_PAGE) { - page = target.page; - if (!isolate_lru_page(page)) { - if (!mem_cgroup_move_account(page, true, - mc.from, mc.to)) { - mc.precharge -= HPAGE_PMD_NR; - mc.moved_charge += HPAGE_PMD_NR; - } - putback_lru_page(page); - } - put_page(page); - } else if (target_type == MC_TARGET_DEVICE) { - page = target.page; - if (!mem_cgroup_move_account(page, true, - mc.from, mc.to)) { - mc.precharge -= HPAGE_PMD_NR; - mc.moved_charge += HPAGE_PMD_NR; - } - put_page(page); - } - spin_unlock(ptl); - return 0; - } - - if (pmd_trans_unstable(pmd)) - return 0; -retry: - pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); - for (; addr != end; addr += PAGE_SIZE) { - pte_t ptent = *(pte++); - bool device = false; - swp_entry_t ent; - - if (!mc.precharge) - break; - - switch (get_mctgt_type(vma, addr, ptent, &target)) { - case MC_TARGET_DEVICE: - device = true; - fallthrough; - case MC_TARGET_PAGE: - page = target.page; - /* - * We can have a part of the split pmd here. Moving it - * can be done but it would be too convoluted so simply - * ignore such a partial THP and keep it in original - * memcg. There should be somebody mapping the head. - */ - if (PageTransCompound(page)) - goto put; - if (!device && isolate_lru_page(page)) - goto put; - if (!mem_cgroup_move_account(page, false, - mc.from, mc.to)) { - mc.precharge--; - /* we uncharge from mc.from later. */ - mc.moved_charge++; - } - if (!device) - putback_lru_page(page); -put: /* get_mctgt_type() gets the page */ - put_page(page); - break; - case MC_TARGET_SWAP: - ent = target.ent; - if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) { - mc.precharge--; - mem_cgroup_id_get_many(mc.to, 1); - /* we fixup other refcnts and charges later. */ - mc.moved_swap++; - } - break; - default: - break; - } - } - pte_unmap_unlock(pte - 1, ptl); - cond_resched(); - - if (addr != end) { - /* - * We have consumed all precharges we got in can_attach(). - * We try charge one by one, but don't do any additional - * charges to mc.to if we have failed in charge once in attach() - * phase. - */ - ret = mem_cgroup_do_precharge(1); - if (!ret) - goto retry; - } - - return ret; + ofp->value = OFP_PEAK_UNSET; + return 0; } -static const struct mm_walk_ops charge_walk_ops = { - .pmd_entry = mem_cgroup_move_charge_pte_range, -}; - -static void mem_cgroup_move_charge(void) +static void peak_release(struct kernfs_open_file *of) { - lru_add_drain_all(); - /* - * Signal lock_page_memcg() to take the memcg's move_lock - * while we're moving its pages to another memcg. Then wait - * for already started RCU-only updates to finish. - */ - atomic_inc(&mc.from->moving_account); - synchronize_rcu(); -retry: - if (unlikely(!mmap_read_trylock(mc.mm))) { - /* - * Someone who are holding the mmap_lock might be waiting in - * waitq. So we cancel all extra charges, wake up all waiters, - * and retry. Because we cancel precharges, we might not be able - * to move enough charges, but moving charge is a best-effort - * feature anyway, so it wouldn't be a big problem. - */ - __mem_cgroup_clear_mc(); - cond_resched(); - goto retry; - } - /* - * When we have consumed all precharges and failed in doing - * additional charge, the page walk just aborts. - */ - walk_page_range(mc.mm, 0, ULONG_MAX, &charge_walk_ops, NULL); - mmap_read_unlock(mc.mm); - atomic_dec(&mc.from->moving_account); -} + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + struct cgroup_of_peak *ofp = of_peak(of); -static void mem_cgroup_move_task(void) -{ - if (mc.to) { - mem_cgroup_move_charge(); - mem_cgroup_clear_mc(); + if (ofp->value == OFP_PEAK_UNSET) { + /* fast path (no writes on this fd) */ + return; } + spin_lock(&memcg->peaks_lock); + list_del(&ofp->list); + spin_unlock(&memcg->peaks_lock); } -#else /* !CONFIG_MMU */ -static int mem_cgroup_can_attach(struct cgroup_taskset *tset) -{ - return 0; -} -static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset) -{ -} -static void mem_cgroup_move_task(void) -{ -} -#endif -#ifdef CONFIG_LRU_GEN -static void mem_cgroup_attach(struct cgroup_taskset *tset) +static ssize_t peak_write(struct kernfs_open_file *of, char *buf, size_t nbytes, + loff_t off, struct page_counter *pc, + struct list_head *watchers) { - struct task_struct *task; - struct cgroup_subsys_state *css; + unsigned long usage; + struct cgroup_of_peak *peer_ctx; + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + struct cgroup_of_peak *ofp = of_peak(of); - /* find the first leader if there is any */ - cgroup_taskset_for_each_leader(task, css, tset) - break; + spin_lock(&memcg->peaks_lock); - if (!task) - return; + usage = page_counter_read(pc); + WRITE_ONCE(pc->local_watermark, usage); - task_lock(task); - if (task->mm && READ_ONCE(task->mm->owner) == task) - lru_gen_migrate_mm(task->mm); - task_unlock(task); -} -#else -static void mem_cgroup_attach(struct cgroup_taskset *tset) -{ -} -#endif /* CONFIG_LRU_GEN */ - -static int seq_puts_memcg_tunable(struct seq_file *m, unsigned long value) -{ - if (value == PAGE_COUNTER_MAX) - seq_puts(m, "max\n"); - else - seq_printf(m, "%llu\n", (u64)value * PAGE_SIZE); + list_for_each_entry(peer_ctx, watchers, list) + if (usage > peer_ctx->value) + WRITE_ONCE(peer_ctx->value, usage); - return 0; -} + /* initial write, register watcher */ + if (ofp->value == OFP_PEAK_UNSET) + list_add(&ofp->list, watchers); -static u64 memory_current_read(struct cgroup_subsys_state *css, - struct cftype *cft) -{ - struct mem_cgroup *memcg = mem_cgroup_from_css(css); + WRITE_ONCE(ofp->value, usage); + spin_unlock(&memcg->peaks_lock); - return (u64)page_counter_read(&memcg->memory) * PAGE_SIZE; + return nbytes; } -static u64 memory_peak_read(struct cgroup_subsys_state *css, - struct cftype *cft) +static ssize_t memory_peak_write(struct kernfs_open_file *of, char *buf, + size_t nbytes, loff_t off) { - struct mem_cgroup *memcg = mem_cgroup_from_css(css); + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); - return (u64)memcg->memory.watermark * PAGE_SIZE; + return peak_write(of, buf, nbytes, off, &memcg->memory, + &memcg->memory_peaks); } +#undef OFP_PEAK_UNSET + static int memory_min_show(struct seq_file *m, void *v) { return seq_puts_memcg_tunable(m, @@ -6412,6 +4387,9 @@ static ssize_t memory_high_write(struct kernfs_open_file *of, page_counter_set_high(&memcg->memory, high); + if (of->file->f_flags & O_NONBLOCK) + goto out; + for (;;) { unsigned long nr_pages = page_counter_read(&memcg->memory); unsigned long reclaimed; @@ -6429,13 +4407,12 @@ static ssize_t memory_high_write(struct kernfs_open_file *of, } reclaimed = try_to_free_mem_cgroup_pages(memcg, nr_pages - high, - GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP, - NULL); + GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP, NULL); if (!reclaimed && !nr_retries--) break; } - +out: memcg_wb_domain_size_changed(memcg); return nbytes; } @@ -6462,6 +4439,9 @@ static ssize_t memory_max_write(struct kernfs_open_file *of, xchg(&memcg->memory.max, max); + if (of->file->f_flags & O_NONBLOCK) + goto out; + for (;;) { unsigned long nr_pages = page_counter_read(&memcg->memory); @@ -6479,8 +4459,7 @@ static ssize_t memory_max_write(struct kernfs_open_file *of, if (nr_reclaims) { if (!try_to_free_mem_cgroup_pages(memcg, nr_pages - max, - GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP, - NULL)) + GFP_KERNEL, MEMCG_RECLAIM_MAY_SWAP, NULL)) nr_reclaims--; continue; } @@ -6488,12 +4467,17 @@ static ssize_t memory_max_write(struct kernfs_open_file *of, memcg_memory_event(memcg, MEMCG_OOM); if (!mem_cgroup_out_of_memory(memcg, GFP_KERNEL, 0)) break; + cond_resched(); } - +out: memcg_wb_domain_size_changed(memcg); return nbytes; } +/* + * Note: don't forget to update the 'samples/cgroup/memcg_event_listener' + * if any new events become available. + */ static void __memory_events_show(struct seq_file *m, atomic_long_t *events) { seq_printf(m, "low %lu\n", atomic_long_read(&events[MEMCG_LOW])); @@ -6504,6 +4488,8 @@ static void __memory_events_show(struct seq_file *m, atomic_long_t *events) atomic_long_read(&events[MEMCG_OOM_KILL])); seq_printf(m, "oom_group_kill %lu\n", atomic_long_read(&events[MEMCG_OOM_GROUP_KILL])); + seq_printf(m, "sock_throttled %lu\n", + atomic_long_read(&events[MEMCG_SOCK_THROTTLED])); } static int memory_events_show(struct seq_file *m, void *v) @@ -6522,14 +4508,16 @@ static int memory_events_local_show(struct seq_file *m, void *v) return 0; } -static int memory_stat_show(struct seq_file *m, void *v) +int memory_stat_show(struct seq_file *m, void *v) { struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + char *buf = kmalloc(SEQ_BUF_SIZE, GFP_KERNEL); + struct seq_buf s; if (!buf) return -ENOMEM; - memory_stat_format(memcg, buf, PAGE_SIZE); + seq_buf_init(&s, buf, SEQ_BUF_SIZE); + memory_stat_format(memcg, &s); seq_puts(m, buf); kfree(buf); return 0; @@ -6539,7 +4527,8 @@ static int memory_stat_show(struct seq_file *m, void *v) static inline unsigned long lruvec_page_state_output(struct lruvec *lruvec, int item) { - return lruvec_page_state(lruvec, item) * memcg_page_state_unit(item); + return lruvec_page_state(lruvec, item) * + memcg_page_state_output_unit(item); } static int memory_numa_stat_show(struct seq_file *m, void *v) @@ -6547,7 +4536,7 @@ static int memory_numa_stat_show(struct seq_file *m, void *v) int i; struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - mem_cgroup_flush_stats(); + mem_cgroup_flush_stats(memcg); for (i = 0; i < ARRAY_SIZE(memory_stats); i++) { int nid; @@ -6576,7 +4565,7 @@ static int memory_oom_group_show(struct seq_file *m, void *v) { struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - seq_printf(m, "%d\n", memcg->oom_group); + seq_printf(m, "%d\n", READ_ONCE(memcg->oom_group)); return 0; } @@ -6598,83 +4587,20 @@ static ssize_t memory_oom_group_write(struct kernfs_open_file *of, if (oom_group != 0 && oom_group != 1) return -EINVAL; - memcg->oom_group = oom_group; + WRITE_ONCE(memcg->oom_group, oom_group); return nbytes; } -enum { - MEMORY_RECLAIM_NODES = 0, - MEMORY_RECLAIM_NULL, -}; - -static const match_table_t if_tokens = { - { MEMORY_RECLAIM_NODES, "nodes=%s" }, - { MEMORY_RECLAIM_NULL, NULL }, -}; - static ssize_t memory_reclaim(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); - unsigned int nr_retries = MAX_RECLAIM_RETRIES; - unsigned long nr_to_reclaim, nr_reclaimed = 0; - unsigned int reclaim_options = MEMCG_RECLAIM_MAY_SWAP | - MEMCG_RECLAIM_PROACTIVE; - char *old_buf, *start; - substring_t args[MAX_OPT_ARGS]; - int token; - char value[256]; - nodemask_t nodemask = NODE_MASK_ALL; - - buf = strstrip(buf); - - old_buf = buf; - nr_to_reclaim = memparse(buf, &buf) / PAGE_SIZE; - if (buf == old_buf) - return -EINVAL; - - buf = strstrip(buf); - - while ((start = strsep(&buf, " ")) != NULL) { - if (!strlen(start)) - continue; - token = match_token(start, if_tokens, args); - match_strlcpy(value, args, sizeof(value)); - switch (token) { - case MEMORY_RECLAIM_NODES: - if (nodelist_parse(value, nodemask) < 0) - return -EINVAL; - break; - default: - return -EINVAL; - } - } - - while (nr_reclaimed < nr_to_reclaim) { - unsigned long reclaimed; - - if (signal_pending(current)) - return -EINTR; - - /* - * This is the final attempt, drain percpu lru caches in the - * hope of introducing more evictable pages for - * try_to_free_mem_cgroup_pages(). - */ - if (!nr_retries) - lru_add_drain_all(); - - reclaimed = try_to_free_mem_cgroup_pages(memcg, - nr_to_reclaim - nr_reclaimed, - GFP_KERNEL, reclaim_options, - &nodemask); - - if (!reclaimed && !nr_retries--) - return -EAGAIN; + int ret; - nr_reclaimed += reclaimed; - } + ret = user_proactive_reclaim(buf, memcg, NULL); + if (ret) + return ret; return nbytes; } @@ -6688,7 +4614,10 @@ static struct cftype memory_files[] = { { .name = "peak", .flags = CFTYPE_NOT_ON_ROOT, - .read_u64 = memory_peak_read, + .open = peak_open, + .release = peak_release, + .seq_show = memory_peak_show, + .write = memory_peak_write, }, { .name = "min", @@ -6758,131 +4687,16 @@ struct cgroup_subsys memory_cgrp_subsys = { .css_free = mem_cgroup_css_free, .css_reset = mem_cgroup_css_reset, .css_rstat_flush = mem_cgroup_css_rstat_flush, - .can_attach = mem_cgroup_can_attach, .attach = mem_cgroup_attach, - .cancel_attach = mem_cgroup_cancel_attach, - .post_attach = mem_cgroup_move_task, + .fork = mem_cgroup_fork, + .exit = mem_cgroup_exit, .dfl_cftypes = memory_files, +#ifdef CONFIG_MEMCG_V1 .legacy_cftypes = mem_cgroup_legacy_files, +#endif .early_init = 0, }; -/* - * This function calculates an individual cgroup's effective - * protection which is derived from its own memory.min/low, its - * parent's and siblings' settings, as well as the actual memory - * distribution in the tree. - * - * The following rules apply to the effective protection values: - * - * 1. At the first level of reclaim, effective protection is equal to - * the declared protection in memory.min and memory.low. - * - * 2. To enable safe delegation of the protection configuration, at - * subsequent levels the effective protection is capped to the - * parent's effective protection. - * - * 3. To make complex and dynamic subtrees easier to configure, the - * user is allowed to overcommit the declared protection at a given - * level. If that is the case, the parent's effective protection is - * distributed to the children in proportion to how much protection - * they have declared and how much of it they are utilizing. - * - * This makes distribution proportional, but also work-conserving: - * if one cgroup claims much more protection than it uses memory, - * the unused remainder is available to its siblings. - * - * 4. Conversely, when the declared protection is undercommitted at a - * given level, the distribution of the larger parental protection - * budget is NOT proportional. A cgroup's protection from a sibling - * is capped to its own memory.min/low setting. - * - * 5. However, to allow protecting recursive subtrees from each other - * without having to declare each individual cgroup's fixed share - * of the ancestor's claim to protection, any unutilized - - * "floating" - protection from up the tree is distributed in - * proportion to each cgroup's *usage*. This makes the protection - * neutral wrt sibling cgroups and lets them compete freely over - * the shared parental protection budget, but it protects the - * subtree as a whole from neighboring subtrees. - * - * Note that 4. and 5. are not in conflict: 4. is about protecting - * against immediate siblings whereas 5. is about protecting against - * neighboring subtrees. - */ -static unsigned long effective_protection(unsigned long usage, - unsigned long parent_usage, - unsigned long setting, - unsigned long parent_effective, - unsigned long siblings_protected) -{ - unsigned long protected; - unsigned long ep; - - protected = min(usage, setting); - /* - * If all cgroups at this level combined claim and use more - * protection then what the parent affords them, distribute - * shares in proportion to utilization. - * - * We are using actual utilization rather than the statically - * claimed protection in order to be work-conserving: claimed - * but unused protection is available to siblings that would - * otherwise get a smaller chunk than what they claimed. - */ - if (siblings_protected > parent_effective) - return protected * parent_effective / siblings_protected; - - /* - * Ok, utilized protection of all children is within what the - * parent affords them, so we know whatever this child claims - * and utilizes is effectively protected. - * - * If there is unprotected usage beyond this value, reclaim - * will apply pressure in proportion to that amount. - * - * If there is unutilized protection, the cgroup will be fully - * shielded from reclaim, but we do return a smaller value for - * protection than what the group could enjoy in theory. This - * is okay. With the overcommit distribution above, effective - * protection is always dependent on how memory is actually - * consumed among the siblings anyway. - */ - ep = protected; - - /* - * If the children aren't claiming (all of) the protection - * afforded to them by the parent, distribute the remainder in - * proportion to the (unprotected) memory of each cgroup. That - * way, cgroups that aren't explicitly prioritized wrt each - * other compete freely over the allowance, but they are - * collectively protected from neighboring trees. - * - * We're using unprotected memory for the weight so that if - * some cgroups DO claim explicit protection, we don't protect - * the same bytes twice. - * - * Check both usage and parent_usage against the respective - * protected values. One should imply the other, but they - * aren't read atomically - make sure the division is sane. - */ - if (!(cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_RECURSIVE_PROT)) - return ep; - if (parent_effective > siblings_protected && - parent_usage > siblings_protected && - usage > protected) { - unsigned long unclaimed; - - unclaimed = parent_effective - siblings_protected; - unclaimed *= usage - protected; - unclaimed /= parent_usage - siblings_protected; - - ep += unclaimed; - } - - return ep; -} - /** * mem_cgroup_calculate_protection - check if memory consumption is in the normal range * @root: the top ancestor of the sub-tree being checked @@ -6894,8 +4708,8 @@ static unsigned long effective_protection(unsigned long usage, void mem_cgroup_calculate_protection(struct mem_cgroup *root, struct mem_cgroup *memcg) { - unsigned long usage, parent_usage; - struct mem_cgroup *parent; + bool recursive_protection = + cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_RECURSIVE_PROT; if (mem_cgroup_disabled()) return; @@ -6903,58 +4717,21 @@ void mem_cgroup_calculate_protection(struct mem_cgroup *root, if (!root) root = root_mem_cgroup; - /* - * Effective values of the reclaim targets are ignored so they - * can be stale. Have a look at mem_cgroup_protection for more - * details. - * TODO: calculation should be more robust so that we do not need - * that special casing. - */ - if (memcg == root) - return; - - usage = page_counter_read(&memcg->memory); - if (!usage) - return; - - parent = parent_mem_cgroup(memcg); - - if (parent == root) { - memcg->memory.emin = READ_ONCE(memcg->memory.min); - memcg->memory.elow = READ_ONCE(memcg->memory.low); - return; - } - - parent_usage = page_counter_read(&parent->memory); - - WRITE_ONCE(memcg->memory.emin, effective_protection(usage, parent_usage, - READ_ONCE(memcg->memory.min), - READ_ONCE(parent->memory.emin), - atomic_long_read(&parent->memory.children_min_usage))); - - WRITE_ONCE(memcg->memory.elow, effective_protection(usage, parent_usage, - READ_ONCE(memcg->memory.low), - READ_ONCE(parent->memory.elow), - atomic_long_read(&parent->memory.children_low_usage))); + page_counter_calculate_protection(&root->memory, &memcg->memory, recursive_protection); } static int charge_memcg(struct folio *folio, struct mem_cgroup *memcg, gfp_t gfp) { - long nr_pages = folio_nr_pages(folio); int ret; - ret = try_charge(memcg, gfp, nr_pages); + ret = try_charge(memcg, gfp, folio_nr_pages(folio)); if (ret) goto out; css_get(&memcg->css); commit_charge(folio, memcg); - - local_irq_disable(); - mem_cgroup_charge_statistics(memcg, nr_pages); - memcg_check_events(memcg, folio_nid(folio)); - local_irq_enable(); + memcg1_commit_charge(folio, memcg); out: return ret; } @@ -6972,6 +4749,40 @@ int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp) } /** + * mem_cgroup_charge_hugetlb - charge the memcg for a hugetlb folio + * @folio: folio being charged + * @gfp: reclaim mode + * + * This function is called when allocating a huge page folio, after the page has + * already been obtained and charged to the appropriate hugetlb cgroup + * controller (if it is enabled). + * + * Returns ENOMEM if the memcg is already full. + * Returns 0 if either the charge was successful, or if we skip the charging. + */ +int mem_cgroup_charge_hugetlb(struct folio *folio, gfp_t gfp) +{ + struct mem_cgroup *memcg = get_mem_cgroup_from_current(); + int ret = 0; + + /* + * Even memcg does not account for hugetlb, we still want to update + * system-level stats via lruvec_stat_mod_folio. Return 0, and skip + * charging the memcg. + */ + if (mem_cgroup_disabled() || !memcg_accounts_hugetlb() || + !memcg || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) + goto out; + + if (charge_memcg(folio, memcg, gfp)) + ret = -ENOMEM; + +out: + mem_cgroup_put(memcg); + return ret; +} + +/** * mem_cgroup_swapin_charge_folio - Charge a newly allocated folio for swapin. * @folio: folio to charge. * @mm: mm context of the victim @@ -7006,39 +4817,6 @@ int mem_cgroup_swapin_charge_folio(struct folio *folio, struct mm_struct *mm, return ret; } -/* - * mem_cgroup_swapin_uncharge_swap - uncharge swap slot - * @entry: swap entry for which the page is charged - * - * Call this function after successfully adding the charged page to swapcache. - * - * Note: This function assumes the page for which swap slot is being uncharged - * is order 0 page. - */ -void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry) -{ - /* - * Cgroup1's unified memory+swap counter has been charged with the - * new swapcache page, finish the transfer by uncharging the swap - * slot. The swap slot would also get uncharged when it dies, but - * it can stick around indefinitely and we'd count the page twice - * the entire time. - * - * Cgroup2 has separate resource counters for memory and swap, - * so this is a non-issue here. Memory and swap charge lifetimes - * correspond 1:1 to page and swap slot lifetimes: we charge the - * page to memory here, and uncharge swap when the slot is freed. - */ - if (!mem_cgroup_disabled() && do_memsw_account()) { - /* - * The swap entry might not get freed for a long time, - * let's not wait for it. The page already received a - * memory+swap charge, drop the swap entry duplicate. - */ - mem_cgroup_uncharge_swap(entry, 1); - } -} - struct uncharge_gather { struct mem_cgroup *memcg; unsigned long nr_memory; @@ -7054,22 +4832,16 @@ static inline void uncharge_gather_clear(struct uncharge_gather *ug) static void uncharge_batch(const struct uncharge_gather *ug) { - unsigned long flags; - if (ug->nr_memory) { - page_counter_uncharge(&ug->memcg->memory, ug->nr_memory); - if (do_memsw_account()) - page_counter_uncharge(&ug->memcg->memsw, ug->nr_memory); - if (ug->nr_kmem) - memcg_account_kmem(ug->memcg, -ug->nr_kmem); - memcg_oom_recover(ug->memcg); + memcg_uncharge(ug->memcg, ug->nr_memory); + if (ug->nr_kmem) { + mod_memcg_state(ug->memcg, MEMCG_KMEM, -ug->nr_kmem); + memcg1_account_kmem(ug->memcg, -ug->nr_kmem); + } + memcg1_oom_recover(ug->memcg); } - local_irq_save(flags); - __count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout); - __this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_memory); - memcg_check_events(ug->memcg, ug->nid); - local_irq_restore(flags); + memcg1_uncharge_batch(ug->memcg, ug->pgpgout, ug->nr_memory, ug->nid); /* drop reference from uncharge_folio */ css_put(&ug->memcg->css); @@ -7128,6 +4900,7 @@ static void uncharge_folio(struct folio *folio, struct uncharge_gather *ug) ug->nr_memory += nr_pages; ug->pgpgout++; + WARN_ON_ONCE(folio_unqueue_deferred_split(folio)); folio->memcg_data = 0; } @@ -7139,7 +4912,7 @@ void __mem_cgroup_uncharge(struct folio *folio) struct uncharge_gather ug; /* Don't touch folio->lru of any random page, pre-check: */ - if (!folio_memcg(folio)) + if (!folio_memcg_charged(folio)) return; uncharge_gather_clear(&ug); @@ -7147,27 +4920,20 @@ void __mem_cgroup_uncharge(struct folio *folio) uncharge_batch(&ug); } -/** - * __mem_cgroup_uncharge_list - uncharge a list of page - * @page_list: list of pages to uncharge - * - * Uncharge a list of pages previously charged with - * __mem_cgroup_charge(). - */ -void __mem_cgroup_uncharge_list(struct list_head *page_list) +void __mem_cgroup_uncharge_folios(struct folio_batch *folios) { struct uncharge_gather ug; - struct folio *folio; + unsigned int i; uncharge_gather_clear(&ug); - list_for_each_entry(folio, page_list, lru) - uncharge_folio(folio, &ug); + for (i = 0; i < folios->nr; i++) + uncharge_folio(folios->folios[i], &ug); if (ug.memcg) uncharge_batch(&ug); } /** - * mem_cgroup_migrate - Charge a folio's replacement. + * mem_cgroup_replace_folio - Charge a folio's replacement. * @old: Currently circulating folio. * @new: Replacement folio. * @@ -7176,11 +4942,10 @@ void __mem_cgroup_uncharge_list(struct list_head *page_list) * * Both folios must be locked, @new->mapping must be set up. */ -void mem_cgroup_migrate(struct folio *old, struct folio *new) +void mem_cgroup_replace_folio(struct folio *old, struct folio *new) { struct mem_cgroup *memcg; long nr_pages = folio_nr_pages(new); - unsigned long flags; VM_BUG_ON_FOLIO(!folio_test_locked(old), old); VM_BUG_ON_FOLIO(!folio_test_locked(new), new); @@ -7191,7 +4956,7 @@ void mem_cgroup_migrate(struct folio *old, struct folio *new) return; /* Page cache replacement: new folio already charged? */ - if (folio_memcg(new)) + if (folio_memcg_charged(new)) return; memcg = folio_memcg(old); @@ -7208,11 +4973,49 @@ void mem_cgroup_migrate(struct folio *old, struct folio *new) css_get(&memcg->css); commit_charge(new, memcg); + memcg1_commit_charge(new, memcg); +} + +/** + * mem_cgroup_migrate - Transfer the memcg data from the old to the new folio. + * @old: Currently circulating folio. + * @new: Replacement folio. + * + * Transfer the memcg data from the old folio to the new folio for migration. + * The old folio's data info will be cleared. Note that the memory counters + * will remain unchanged throughout the process. + * + * Both folios must be locked, @new->mapping must be set up. + */ +void mem_cgroup_migrate(struct folio *old, struct folio *new) +{ + struct mem_cgroup *memcg; - local_irq_save(flags); - mem_cgroup_charge_statistics(memcg, nr_pages); - memcg_check_events(memcg, folio_nid(new)); - local_irq_restore(flags); + VM_BUG_ON_FOLIO(!folio_test_locked(old), old); + VM_BUG_ON_FOLIO(!folio_test_locked(new), new); + VM_BUG_ON_FOLIO(folio_test_anon(old) != folio_test_anon(new), new); + VM_BUG_ON_FOLIO(folio_nr_pages(old) != folio_nr_pages(new), new); + VM_BUG_ON_FOLIO(folio_test_lru(old), old); + + if (mem_cgroup_disabled()) + return; + + memcg = folio_memcg(old); + /* + * Note that it is normal to see !memcg for a hugetlb folio. + * For e.g, itt could have been allocated when memory_hugetlb_accounting + * was not selected. + */ + VM_WARN_ON_ONCE_FOLIO(!folio_test_hugetlb(old) && !memcg, old); + if (!memcg) + return; + + /* Transfer the charge and the css ref */ + commit_charge(new, memcg); + + /* Warning should never happen, so don't worry about refcount non-0 */ + WARN_ON_ONCE(folio_unqueue_deferred_split(old)); + old->memcg_data = 0; } DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key); @@ -7233,7 +5036,7 @@ void mem_cgroup_sk_alloc(struct sock *sk) memcg = mem_cgroup_from_task(current); if (mem_cgroup_is_root(memcg)) goto out; - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcpmem_active) + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg1_tcpmem_active(memcg)) goto out; if (css_tryget(&memcg->css)) sk->sk_memcg = memcg; @@ -7243,38 +5046,46 @@ out: void mem_cgroup_sk_free(struct sock *sk) { - if (sk->sk_memcg) - css_put(&sk->sk_memcg->css); + struct mem_cgroup *memcg = mem_cgroup_from_sk(sk); + + if (memcg) + css_put(&memcg->css); +} + +void mem_cgroup_sk_inherit(const struct sock *sk, struct sock *newsk) +{ + struct mem_cgroup *memcg; + + if (sk->sk_memcg == newsk->sk_memcg) + return; + + mem_cgroup_sk_free(newsk); + + memcg = mem_cgroup_from_sk(sk); + if (memcg) + css_get(&memcg->css); + + newsk->sk_memcg = sk->sk_memcg; } /** - * mem_cgroup_charge_skmem - charge socket memory - * @memcg: memcg to charge + * mem_cgroup_sk_charge - charge socket memory + * @sk: socket in memcg to charge * @nr_pages: number of pages to charge * @gfp_mask: reclaim mode * * Charges @nr_pages to @memcg. Returns %true if the charge fit within * @memcg's configured limit, %false if it doesn't. */ -bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages, - gfp_t gfp_mask) +bool mem_cgroup_sk_charge(const struct sock *sk, unsigned int nr_pages, + gfp_t gfp_mask) { - if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { - struct page_counter *fail; + struct mem_cgroup *memcg = mem_cgroup_from_sk(sk); - if (page_counter_try_charge(&memcg->tcpmem, nr_pages, &fail)) { - memcg->tcpmem_pressure = 0; - return true; - } - memcg->tcpmem_pressure = 1; - if (gfp_mask & __GFP_NOFAIL) { - page_counter_charge(&memcg->tcpmem, nr_pages); - return true; - } - return false; - } + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) + return memcg1_charge_skmem(memcg, nr_pages, gfp_mask); - if (try_charge(memcg, gfp_mask, nr_pages) == 0) { + if (try_charge_memcg(memcg, gfp_mask, nr_pages) == 0) { mod_memcg_state(memcg, MEMCG_SOCK, nr_pages); return true; } @@ -7283,14 +5094,16 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages, } /** - * mem_cgroup_uncharge_skmem - uncharge socket memory - * @memcg: memcg to uncharge + * mem_cgroup_sk_uncharge - uncharge socket memory + * @sk: socket in memcg to uncharge * @nr_pages: number of pages to uncharge */ -void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) +void mem_cgroup_sk_uncharge(const struct sock *sk, unsigned int nr_pages) { + struct mem_cgroup *memcg = mem_cgroup_from_sk(sk); + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { - page_counter_uncharge(&memcg->tcpmem, nr_pages); + memcg1_uncharge_skmem(memcg, nr_pages); return; } @@ -7310,22 +5123,25 @@ static int __init cgroup_memory(char *s) cgroup_memory_nosocket = true; if (!strcmp(token, "nokmem")) cgroup_memory_nokmem = true; + if (!strcmp(token, "nobpf")) + cgroup_memory_nobpf = true; } return 1; } __setup("cgroup.memory=", cgroup_memory); /* - * subsys_initcall() for memory controller. + * Memory controller init before cgroup_init() initialize root_mem_cgroup. * * Some parts like memcg_hotplug_cpu_dead() have to be initialized from this * context because of lock dependencies (cgroup_lock -> cpu hotplug) but * basically everything that doesn't depend on a specific mem_cgroup structure * should be initialized from here. */ -static int __init mem_cgroup_init(void) +int __init mem_cgroup_init(void) { - int cpu, node; + unsigned int memcg_size; + int cpu; /* * Currently s32 type (can refer to struct batched_lruvec_stat) is @@ -7338,113 +5154,24 @@ static int __init mem_cgroup_init(void) cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD, "mm/memctrl:dead", NULL, memcg_hotplug_cpu_dead); - for_each_possible_cpu(cpu) + for_each_possible_cpu(cpu) { INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work, - drain_local_stock); - - for_each_node(node) { - struct mem_cgroup_tree_per_node *rtpn; + drain_local_memcg_stock); + INIT_WORK(&per_cpu_ptr(&obj_stock, cpu)->work, + drain_local_obj_stock); + } - rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, - node_online(node) ? node : NUMA_NO_NODE); + memcg_size = struct_size_t(struct mem_cgroup, nodeinfo, nr_node_ids); + memcg_cachep = kmem_cache_create("mem_cgroup", memcg_size, 0, + SLAB_PANIC | SLAB_HWCACHE_ALIGN, NULL); - rtpn->rb_root = RB_ROOT; - rtpn->rb_rightmost = NULL; - spin_lock_init(&rtpn->lock); - soft_limit_tree.rb_tree_per_node[node] = rtpn; - } + memcg_pn_cachep = KMEM_CACHE(mem_cgroup_per_node, + SLAB_PANIC | SLAB_HWCACHE_ALIGN); return 0; } -subsys_initcall(mem_cgroup_init); #ifdef CONFIG_SWAP -static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg) -{ - while (!refcount_inc_not_zero(&memcg->id.ref)) { - /* - * The root cgroup cannot be destroyed, so it's refcount must - * always be >= 1. - */ - if (WARN_ON_ONCE(mem_cgroup_is_root(memcg))) { - VM_BUG_ON(1); - break; - } - memcg = parent_mem_cgroup(memcg); - if (!memcg) - memcg = root_mem_cgroup; - } - return memcg; -} - -/** - * mem_cgroup_swapout - transfer a memsw charge to swap - * @folio: folio whose memsw charge to transfer - * @entry: swap entry to move the charge to - * - * Transfer the memsw charge of @folio to @entry. - */ -void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry) -{ - struct mem_cgroup *memcg, *swap_memcg; - unsigned int nr_entries; - unsigned short oldid; - - VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); - VM_BUG_ON_FOLIO(folio_ref_count(folio), folio); - - if (mem_cgroup_disabled()) - return; - - if (!do_memsw_account()) - return; - - memcg = folio_memcg(folio); - - VM_WARN_ON_ONCE_FOLIO(!memcg, folio); - if (!memcg) - return; - - /* - * In case the memcg owning these pages has been offlined and doesn't - * have an ID allocated to it anymore, charge the closest online - * ancestor for the swap instead and transfer the memory+swap charge. - */ - swap_memcg = mem_cgroup_id_get_online(memcg); - nr_entries = folio_nr_pages(folio); - /* Get references for the tail pages, too */ - if (nr_entries > 1) - mem_cgroup_id_get_many(swap_memcg, nr_entries - 1); - oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg), - nr_entries); - VM_BUG_ON_FOLIO(oldid, folio); - mod_memcg_state(swap_memcg, MEMCG_SWAP, nr_entries); - - folio->memcg_data = 0; - - if (!mem_cgroup_is_root(memcg)) - page_counter_uncharge(&memcg->memory, nr_entries); - - if (memcg != swap_memcg) { - if (!mem_cgroup_is_root(swap_memcg)) - page_counter_charge(&swap_memcg->memsw, nr_entries); - page_counter_uncharge(&memcg->memsw, nr_entries); - } - - /* - * Interrupts should be disabled here because the caller holds the - * i_pages lock which is taken with interrupts-off. It is - * important here to have the interrupts disabled because it is the - * only synchronisation we have for updating the per-CPU variables. - */ - memcg_stats_lock(); - mem_cgroup_charge_statistics(memcg, -nr_entries); - memcg_stats_unlock(); - memcg_check_events(memcg, folio_nid(folio)); - - css_put(&memcg->css); -} - /** * __mem_cgroup_try_charge_swap - try charging swap space for a folio * @folio: folio being added to swap @@ -7459,7 +5186,6 @@ int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry) unsigned int nr_pages = folio_nr_pages(folio); struct page_counter *counter; struct mem_cgroup *memcg; - unsigned short oldid; if (do_memsw_account()) return 0; @@ -7488,10 +5214,10 @@ int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry) /* Get references for the tail pages, too */ if (nr_pages > 1) mem_cgroup_id_get_many(memcg, nr_pages - 1); - oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg), nr_pages); - VM_BUG_ON_FOLIO(oldid, folio); mod_memcg_state(memcg, MEMCG_SWAP, nr_pages); + swap_cgroup_record(folio, mem_cgroup_id(memcg), entry); + return 0; } @@ -7505,10 +5231,7 @@ void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages) struct mem_cgroup *memcg; unsigned short id; - if (mem_cgroup_disabled()) - return; - - id = swap_cgroup_record(entry, 0, nr_pages); + id = swap_cgroup_clear(entry, nr_pages); rcu_read_lock(); memcg = mem_cgroup_from_id(id); if (memcg) { @@ -7565,9 +5288,13 @@ bool mem_cgroup_swap_full(struct folio *folio) static int __init setup_swap_account(char *s) { - pr_warn_once("The swapaccount= commandline option is deprecated. " - "Please report your usecase to linux-mm@kvack.org if you " - "depend on this functionality.\n"); + bool res; + + if (!kstrtobool(s, &res) && !res) + pr_warn_once("The swapaccount=0 commandline option is deprecated " + "in favor of configuring swap control via cgroupfs. " + "Please report your usecase to linux-mm@kvack.org if you " + "depend on this functionality.\n"); return 1; } __setup("swapaccount=", setup_swap_account); @@ -7580,6 +5307,22 @@ static u64 swap_current_read(struct cgroup_subsys_state *css, return (u64)page_counter_read(&memcg->swap) * PAGE_SIZE; } +static int swap_peak_show(struct seq_file *sf, void *v) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf)); + + return peak_show(sf, v, &memcg->swap); +} + +static ssize_t swap_peak_write(struct kernfs_open_file *of, char *buf, + size_t nbytes, loff_t off) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + + return peak_write(of, buf, nbytes, off, &memcg->swap, + &memcg->swap_peaks); +} + static int swap_high_show(struct seq_file *m, void *v) { return seq_puts_memcg_tunable(m, @@ -7659,6 +5402,14 @@ static struct cftype swap_files[] = { .write = swap_max_write, }, { + .name = "swap.peak", + .flags = CFTYPE_NOT_ON_ROOT, + .open = peak_open, + .release = peak_release, + .seq_show = swap_peak_show, + .write = swap_peak_write, + }, + { .name = "swap.events", .flags = CFTYPE_NOT_ON_ROOT, .file_offset = offsetof(struct mem_cgroup, swap_events_file), @@ -7667,34 +5418,7 @@ static struct cftype swap_files[] = { { } /* terminate */ }; -static struct cftype memsw_files[] = { - { - .name = "memsw.usage_in_bytes", - .private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE), - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "memsw.max_usage_in_bytes", - .private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE), - .write = mem_cgroup_reset, - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "memsw.limit_in_bytes", - .private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT), - .write = mem_cgroup_write, - .read_u64 = mem_cgroup_read_u64, - }, - { - .name = "memsw.failcnt", - .private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT), - .write = mem_cgroup_reset, - .read_u64 = mem_cgroup_read_u64, - }, - { }, /* terminate */ -}; - -#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) +#ifdef CONFIG_ZSWAP /** * obj_cgroup_may_zswap - check if this cgroup can zswap * @objcg: the object cgroup @@ -7703,7 +5427,7 @@ static struct cftype memsw_files[] = { * * This doesn't check for specific headroom, and it is not atomic * either. But with zswap, the size of the allocation is only known - * once compression has occured, and this optimistic pre-check avoids + * once compression has occurred, and this optimistic pre-check avoids * spending cycles on compression when there is already no room left * or zswap is disabled altogether somewhere in the hierarchy. */ @@ -7728,7 +5452,8 @@ bool obj_cgroup_may_zswap(struct obj_cgroup *objcg) break; } - cgroup_rstat_flush(memcg->css.cgroup); + /* Force flush to get accurate stats for charging */ + __mem_cgroup_flush_stats(memcg, true); pages = memcg_page_state(memcg, MEMCG_ZSWAP_B) / PAGE_SIZE; if (pages < max) continue; @@ -7744,8 +5469,8 @@ bool obj_cgroup_may_zswap(struct obj_cgroup *objcg) * @objcg: the object cgroup * @size: size of compressed object * - * This forces the charge after obj_cgroup_may_swap() allowed - * compression and storage in zwap for this cgroup to go ahead. + * This forces the charge after obj_cgroup_may_zswap() allowed + * compression and storage in zswap for this cgroup to go ahead. */ void obj_cgroup_charge_zswap(struct obj_cgroup *objcg, size_t size) { @@ -7790,11 +5515,26 @@ void obj_cgroup_uncharge_zswap(struct obj_cgroup *objcg, size_t size) rcu_read_unlock(); } +bool mem_cgroup_zswap_writeback_enabled(struct mem_cgroup *memcg) +{ + /* if zswap is disabled, do not block pages going to the swapping device */ + if (!zswap_is_enabled()) + return true; + + for (; memcg; memcg = parent_mem_cgroup(memcg)) + if (!READ_ONCE(memcg->zswap_writeback)) + return false; + + return true; +} + static u64 zswap_current_read(struct cgroup_subsys_state *css, struct cftype *cft) { - cgroup_rstat_flush(css->cgroup); - return memcg_page_state(mem_cgroup_from_css(css), MEMCG_ZSWAP_B); + struct mem_cgroup *memcg = mem_cgroup_from_css(css); + + mem_cgroup_flush_stats(memcg); + return memcg_page_state(memcg, MEMCG_ZSWAP_B); } static int zswap_max_show(struct seq_file *m, void *v) @@ -7820,6 +5560,31 @@ static ssize_t zswap_max_write(struct kernfs_open_file *of, return nbytes; } +static int zswap_writeback_show(struct seq_file *m, void *v) +{ + struct mem_cgroup *memcg = mem_cgroup_from_seq(m); + + seq_printf(m, "%d\n", READ_ONCE(memcg->zswap_writeback)); + return 0; +} + +static ssize_t zswap_writeback_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + int zswap_writeback; + ssize_t parse_ret = kstrtoint(strstrip(buf), 0, &zswap_writeback); + + if (parse_ret) + return parse_ret; + + if (zswap_writeback != 0 && zswap_writeback != 1) + return -EINVAL; + + WRITE_ONCE(memcg->zswap_writeback, zswap_writeback); + return nbytes; +} + static struct cftype zswap_files[] = { { .name = "zswap.current", @@ -7832,9 +5597,14 @@ static struct cftype zswap_files[] = { .seq_show = zswap_max_show, .write = zswap_max_write, }, + { + .name = "zswap.writeback", + .seq_show = zswap_writeback_show, + .write = zswap_writeback_write, + }, { } /* terminate */ }; -#endif /* CONFIG_MEMCG_KMEM && CONFIG_ZSWAP */ +#endif /* CONFIG_ZSWAP */ static int __init mem_cgroup_swap_init(void) { @@ -7842,8 +5612,10 @@ static int __init mem_cgroup_swap_init(void) return 0; WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, swap_files)); +#ifdef CONFIG_MEMCG_V1 WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, memsw_files)); -#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP) +#endif +#ifdef CONFIG_ZSWAP WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, zswap_files)); #endif return 0; @@ -7851,3 +5623,21 @@ static int __init mem_cgroup_swap_init(void) subsys_initcall(mem_cgroup_swap_init); #endif /* CONFIG_SWAP */ + +bool mem_cgroup_node_allowed(struct mem_cgroup *memcg, int nid) +{ + return memcg ? cpuset_node_allowed(memcg->css.cgroup, nid) : true; +} + +void mem_cgroup_show_protected_memory(struct mem_cgroup *memcg) +{ + if (mem_cgroup_disabled() || !cgroup_subsys_on_dfl(memory_cgrp_subsys)) + return; + + if (!memcg) + memcg = root_mem_cgroup; + + pr_warn("Memory cgroup min protection %lukB -- low protection %lukB", + K(atomic_long_read(&memcg->memory.children_min_usage)*PAGE_SIZE), + K(atomic_long_read(&memcg->memory.children_low_usage)*PAGE_SIZE)); +} |