diff options
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 326 |
1 files changed, 278 insertions, 48 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index b836e7f00309..6a921890739f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -233,6 +233,21 @@ enum res_type { /* Used for OOM nofiier */ #define OOM_CONTROL (0) +/* + * 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)) + /* Some nice accessors for the vmpressure. */ struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg) { @@ -246,12 +261,7 @@ struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr) return &container_of(vmpr, struct mem_cgroup, vmpressure)->css; } -static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) -{ - return (memcg == root_mem_cgroup); -} - -#ifndef CONFIG_SLOB +#ifdef CONFIG_MEMCG_KMEM /* * This will be the memcg's index in each cache's ->memcg_params.memcg_caches. * The main reason for not using cgroup id for this: @@ -305,7 +315,135 @@ EXPORT_SYMBOL(memcg_kmem_enabled_key); struct workqueue_struct *memcg_kmem_cache_wq; -#endif /* !CONFIG_SLOB */ +static int memcg_shrinker_map_size; +static DEFINE_MUTEX(memcg_shrinker_map_mutex); + +static void memcg_free_shrinker_map_rcu(struct rcu_head *head) +{ + kvfree(container_of(head, struct memcg_shrinker_map, rcu)); +} + +static int memcg_expand_one_shrinker_map(struct mem_cgroup *memcg, + int size, int old_size) +{ + struct memcg_shrinker_map *new, *old; + int nid; + + lockdep_assert_held(&memcg_shrinker_map_mutex); + + for_each_node(nid) { + old = rcu_dereference_protected( + mem_cgroup_nodeinfo(memcg, nid)->shrinker_map, true); + /* Not yet online memcg */ + if (!old) + return 0; + + new = kvmalloc(sizeof(*new) + size, GFP_KERNEL); + if (!new) + return -ENOMEM; + + /* Set all old bits, clear all new bits */ + memset(new->map, (int)0xff, old_size); + memset((void *)new->map + old_size, 0, size - old_size); + + rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, new); + call_rcu(&old->rcu, memcg_free_shrinker_map_rcu); + } + + return 0; +} + +static void memcg_free_shrinker_maps(struct mem_cgroup *memcg) +{ + struct mem_cgroup_per_node *pn; + struct memcg_shrinker_map *map; + int nid; + + if (mem_cgroup_is_root(memcg)) + return; + + for_each_node(nid) { + pn = mem_cgroup_nodeinfo(memcg, nid); + map = rcu_dereference_protected(pn->shrinker_map, true); + if (map) + kvfree(map); + rcu_assign_pointer(pn->shrinker_map, NULL); + } +} + +static int memcg_alloc_shrinker_maps(struct mem_cgroup *memcg) +{ + struct memcg_shrinker_map *map; + int nid, size, ret = 0; + + if (mem_cgroup_is_root(memcg)) + return 0; + + mutex_lock(&memcg_shrinker_map_mutex); + size = memcg_shrinker_map_size; + for_each_node(nid) { + map = kvzalloc(sizeof(*map) + size, GFP_KERNEL); + if (!map) { + memcg_free_shrinker_maps(memcg); + ret = -ENOMEM; + break; + } + rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, map); + } + mutex_unlock(&memcg_shrinker_map_mutex); + + return ret; +} + +int memcg_expand_shrinker_maps(int new_id) +{ + int size, old_size, ret = 0; + struct mem_cgroup *memcg; + + size = DIV_ROUND_UP(new_id + 1, BITS_PER_LONG) * sizeof(unsigned long); + old_size = memcg_shrinker_map_size; + if (size <= old_size) + return 0; + + mutex_lock(&memcg_shrinker_map_mutex); + if (!root_mem_cgroup) + goto unlock; + + for_each_mem_cgroup(memcg) { + if (mem_cgroup_is_root(memcg)) + continue; + ret = memcg_expand_one_shrinker_map(memcg, size, old_size); + if (ret) + goto unlock; + } +unlock: + if (!ret) + memcg_shrinker_map_size = size; + mutex_unlock(&memcg_shrinker_map_mutex); + return ret; +} + +void memcg_set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id) +{ + if (shrinker_id >= 0 && memcg && !mem_cgroup_is_root(memcg)) { + struct memcg_shrinker_map *map; + + rcu_read_lock(); + map = rcu_dereference(memcg->nodeinfo[nid]->shrinker_map); + /* Pairs with smp mb in shrink_slab() */ + smp_mb__before_atomic(); + set_bit(shrinker_id, map->map); + rcu_read_unlock(); + } +} + +#else /* CONFIG_MEMCG_KMEM */ +static int memcg_alloc_shrinker_maps(struct mem_cgroup *memcg) +{ + return 0; +} +static void memcg_free_shrinker_maps(struct mem_cgroup *memcg) { } +#endif /* CONFIG_MEMCG_KMEM */ /** * mem_cgroup_css_from_page - css of the memcg associated with a page @@ -678,9 +816,20 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) } EXPORT_SYMBOL(mem_cgroup_from_task); -static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) +/** + * get_mem_cgroup_from_mm: Obtain a reference on given mm_struct's memcg. + * @mm: mm from which memcg should be extracted. It can be NULL. + * + * Obtain a reference on mm->memcg and returns it if successful. Otherwise + * root_mem_cgroup is returned. However if mem_cgroup is disabled, NULL is + * returned. + */ +struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) { - struct mem_cgroup *memcg = NULL; + struct mem_cgroup *memcg; + + if (mem_cgroup_disabled()) + return NULL; rcu_read_lock(); do { @@ -700,6 +849,46 @@ static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) rcu_read_unlock(); return memcg; } +EXPORT_SYMBOL(get_mem_cgroup_from_mm); + +/** + * get_mem_cgroup_from_page: Obtain a reference on given page's memcg. + * @page: page from which memcg should be extracted. + * + * Obtain a reference on page->memcg and returns it if successful. Otherwise + * root_mem_cgroup is returned. + */ +struct mem_cgroup *get_mem_cgroup_from_page(struct page *page) +{ + struct mem_cgroup *memcg = page->mem_cgroup; + + if (mem_cgroup_disabled()) + return NULL; + + rcu_read_lock(); + if (!memcg || !css_tryget_online(&memcg->css)) + memcg = root_mem_cgroup; + rcu_read_unlock(); + return memcg; +} +EXPORT_SYMBOL(get_mem_cgroup_from_page); + +/** + * If current->active_memcg is non-NULL, do not fallback to current->mm->memcg. + */ +static __always_inline struct mem_cgroup *get_mem_cgroup_from_current(void) +{ + if (unlikely(current->active_memcg)) { + struct mem_cgroup *memcg = root_mem_cgroup; + + rcu_read_lock(); + if (css_tryget_online(¤t->active_memcg->css)) + memcg = current->active_memcg; + rcu_read_unlock(); + return memcg; + } + return get_mem_cgroup_from_mm(current->mm); +} /** * mem_cgroup_iter - iterate over memory cgroup hierarchy @@ -862,21 +1051,6 @@ static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg) } } -/* - * 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)) - /** * mem_cgroup_scan_tasks - iterate over tasks of a memory cgroup hierarchy * @memcg: hierarchy root @@ -1483,28 +1657,53 @@ static void memcg_oom_recover(struct mem_cgroup *memcg) __wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg); } -static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) +enum oom_status { + OOM_SUCCESS, + OOM_FAILED, + OOM_ASYNC, + OOM_SKIPPED +}; + +static enum oom_status mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order) { - if (!current->memcg_may_oom || order > PAGE_ALLOC_COSTLY_ORDER) - return; + if (order > PAGE_ALLOC_COSTLY_ORDER) + return OOM_SKIPPED; + /* * 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. * - * Also, the caller may handle a failed allocation gracefully - * (like optional page cache readahead) and so an OOM killer - * invocation might not even be necessary. + * 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. * - * That's why we don't do anything here except remember the - * OOM context and then deal with it at the end of the page - * fault when the stack is unwound, the locks are released, - * and when we know whether the fault was overall successful. + * 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. */ - css_get(&memcg->css); - current->memcg_in_oom = memcg; - current->memcg_oom_gfp_mask = mask; - current->memcg_oom_order = order; + if (memcg->oom_kill_disable) { + if (!current->in_user_fault) + return OOM_SKIPPED; + css_get(&memcg->css); + current->memcg_in_oom = memcg; + current->memcg_oom_gfp_mask = mask; + current->memcg_oom_order = order; + + return OOM_ASYNC; + } + + if (mem_cgroup_out_of_memory(memcg, mask, order)) + return OOM_SUCCESS; + + WARN(1,"Memory cgroup charge failed because of no reclaimable memory! " + "This looks like a misconfiguration or a kernel bug."); + return OOM_FAILED; } /** @@ -1899,6 +2098,8 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, unsigned long nr_reclaimed; bool may_swap = true; bool drained = false; + bool oomed = false; + enum oom_status oom_status; if (mem_cgroup_is_root(memcg)) return 0; @@ -1986,6 +2187,9 @@ retry: if (nr_retries--) goto retry; + if (gfp_mask & __GFP_RETRY_MAYFAIL && oomed) + goto nomem; + if (gfp_mask & __GFP_NOFAIL) goto force; @@ -1994,8 +2198,23 @@ retry: memcg_memory_event(mem_over_limit, MEMCG_OOM); - mem_cgroup_oom(mem_over_limit, gfp_mask, + /* + * keep retrying as long as the memcg oom killer is able to make + * a forward progress or bypass the charge if the oom killer + * couldn't make any progress. + */ + oom_status = mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(nr_pages * PAGE_SIZE)); + switch (oom_status) { + case OOM_SUCCESS: + nr_retries = MEM_CGROUP_RECLAIM_RETRIES; + oomed = true; + goto retry; + case OOM_FAILED: + goto force; + default: + goto nomem; + } nomem: if (!(gfp_mask & __GFP_NOFAIL)) return -ENOMEM; @@ -2119,7 +2338,7 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg, unlock_page_lru(page, isolated); } -#ifndef CONFIG_SLOB +#ifdef CONFIG_MEMCG_KMEM static int memcg_alloc_cache_id(void) { int id, size; @@ -2261,7 +2480,7 @@ struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep) if (current->memcg_kmem_skip_account) return cachep; - memcg = get_mem_cgroup_from_mm(current->mm); + memcg = get_mem_cgroup_from_current(); kmemcg_id = READ_ONCE(memcg->kmemcg_id); if (kmemcg_id < 0) goto out; @@ -2345,7 +2564,7 @@ int memcg_kmem_charge(struct page *page, gfp_t gfp, int order) if (memcg_kmem_bypass()) return 0; - memcg = get_mem_cgroup_from_mm(current->mm); + memcg = get_mem_cgroup_from_current(); if (!mem_cgroup_is_root(memcg)) { ret = memcg_kmem_charge_memcg(page, gfp, order, memcg); if (!ret) @@ -2384,7 +2603,7 @@ void memcg_kmem_uncharge(struct page *page, int order) css_put_many(&memcg->css, nr_pages); } -#endif /* !CONFIG_SLOB */ +#endif /* CONFIG_MEMCG_KMEM */ #ifdef CONFIG_TRANSPARENT_HUGEPAGE @@ -2779,7 +2998,7 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, } } -#ifndef CONFIG_SLOB +#ifdef CONFIG_MEMCG_KMEM static int memcg_online_kmem(struct mem_cgroup *memcg) { int memcg_id; @@ -2851,7 +3070,7 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg) } rcu_read_unlock(); - memcg_drain_all_list_lrus(kmemcg_id, parent->kmemcg_id); + memcg_drain_all_list_lrus(kmemcg_id, parent); memcg_free_cache_id(kmemcg_id); } @@ -2879,7 +3098,7 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg) static void memcg_free_kmem(struct mem_cgroup *memcg) { } -#endif /* !CONFIG_SLOB */ +#endif /* CONFIG_MEMCG_KMEM */ static int memcg_update_kmem_max(struct mem_cgroup *memcg, unsigned long max) @@ -4183,7 +4402,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void) INIT_LIST_HEAD(&memcg->event_list); spin_lock_init(&memcg->event_list_lock); memcg->socket_pressure = jiffies; -#ifndef CONFIG_SLOB +#ifdef CONFIG_MEMCG_KMEM memcg->kmemcg_id = -1; #endif #ifdef CONFIG_CGROUP_WRITEBACK @@ -4260,6 +4479,16 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css) { struct mem_cgroup *memcg = mem_cgroup_from_css(css); + /* + * A memcg must be visible for memcg_expand_shrinker_maps() + * by the time the maps are allocated. So, we allocate maps + * here, when for_each_mem_cgroup() can't skip it. + */ + if (memcg_alloc_shrinker_maps(memcg)) { + mem_cgroup_id_remove(memcg); + return -ENOMEM; + } + /* Online state pins memcg ID, memcg ID pins CSS */ atomic_set(&memcg->id.ref, 1); css_get(css); @@ -4312,6 +4541,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) vmpressure_cleanup(&memcg->vmpressure); cancel_work_sync(&memcg->high_work); mem_cgroup_remove_from_trees(memcg); + memcg_free_shrinker_maps(memcg); memcg_free_kmem(memcg); mem_cgroup_free(memcg); } @@ -6023,7 +6253,7 @@ static int __init mem_cgroup_init(void) { int cpu, node; -#ifndef CONFIG_SLOB +#ifdef CONFIG_MEMCG_KMEM /* * Kmem cache creation is mostly done with the slab_mutex held, * so use a workqueue with limited concurrency to avoid stalling |