diff options
Diffstat (limited to 'include/linux/cgroup-defs.h')
| -rw-r--r-- | include/linux/cgroup-defs.h | 220 |
1 files changed, 173 insertions, 47 deletions
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index 8a0d5466c7be..b760a3c470a5 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -71,9 +71,6 @@ enum { /* Cgroup is frozen. */ CGRP_FROZEN, - - /* Control group has to be killed. */ - CGRP_KILL, }; /* cgroup_root->flags */ @@ -94,6 +91,12 @@ enum { * cgroup_threadgroup_rwsem. This makes hot path operations such as * forks and exits into the slow path and more expensive. * + * Alleviate the contention between fork, exec, exit operations and + * writing to cgroup.procs by taking a per threadgroup rwsem instead of + * the global cgroup_threadgroup_rwsem. Fork and other operations + * from threads in different thread groups no longer contend with + * writing to cgroup.procs. + * * The static usage pattern of creating a cgroup, enabling controllers, * and then seeding it with CLONE_INTO_CGROUP doesn't require write * locking cgroup_threadgroup_rwsem and thus doesn't benefit from @@ -115,6 +118,16 @@ enum { * Enable recursive subtree protection */ CGRP_ROOT_MEMORY_RECURSIVE_PROT = (1 << 18), + + /* + * Enable hugetlb accounting for the memory controller. + */ + CGRP_ROOT_MEMORY_HUGETLB_ACCOUNTING = (1 << 19), + + /* + * Enable legacy local pids.events. + */ + CGRP_ROOT_PIDS_LOCAL_EVENTS = (1 << 20), }; /* cftype->flags */ @@ -133,6 +146,17 @@ enum { __CFTYPE_ADDED = (1 << 18), }; +enum cgroup_attach_lock_mode { + /* Default */ + CGRP_ATTACH_LOCK_GLOBAL, + + /* When pid=0 && threadgroup=false, see comments in cgroup_procs_write_start */ + CGRP_ATTACH_LOCK_NONE, + + /* When favordynmods is on, see comments above CGRP_ROOT_FAVOR_DYNMODS */ + CGRP_ATTACH_LOCK_PER_THREADGROUP, +}; + /* * cgroup_file is the handle for a file instance created in a cgroup which * is used, for example, to generate file changed notifications. This can @@ -162,13 +186,31 @@ struct cgroup_subsys_state { /* reference count - access via css_[try]get() and css_put() */ struct percpu_ref refcnt; - /* siblings list anchored at the parent's ->children */ + /* + * Depending on the context, this field is initialized + * via css_rstat_init() at different places: + * + * when css is associated with cgroup::self + * when css->cgroup is the root cgroup + * performed in cgroup_init() + * when css->cgroup is not the root cgroup + * performed in cgroup_create() + * when css is associated with a subsystem + * when css->cgroup is the root cgroup + * performed in cgroup_init_subsys() in the non-early path + * when css->cgroup is not the root cgroup + * performed in css_create() + */ + struct css_rstat_cpu __percpu *rstat_cpu; + + /* + * siblings list anchored at the parent's ->children + * + * linkage is protected by cgroup_mutex or RCU + */ struct list_head sibling; struct list_head children; - /* flush target list anchored at cgrp->rstat_css_list */ - struct list_head rstat_css_node; - /* * PI: Subsys-unique ID. 0 is unused and root is always 1. The * matching css can be looked up using css_from_id(). @@ -200,6 +242,24 @@ struct cgroup_subsys_state { * fields of the containing structure. */ struct cgroup_subsys_state *parent; + + /* + * Keep track of total numbers of visible descendant CSSes. + * The total number of dying CSSes is tracked in + * css->cgroup->nr_dying_subsys[ssid]. + * Protected by cgroup_mutex. + */ + int nr_descendants; + + /* + * A singly-linked list of css structures to be rstat flushed. + * This is a scratch field to be used exclusively by + * css_rstat_flush(). + * + * Protected by rstat_base_lock when css is cgroup::self. + * Protected by css->ss->rstat_ss_lock otherwise. + */ + struct cgroup_subsys_state *rstat_flush_next; }; /* @@ -238,7 +298,7 @@ struct css_set { * Lists running through all tasks using this cgroup group. * mg_tasks lists tasks which belong to this cset but are in the * process of being migrated out or in. Protected by - * css_set_rwsem, but, during migration, once tasks are moved to + * css_set_lock, but, during migration, once tasks are moved to * mg_tasks, it can be read safely while holding cgroup_mutex. */ struct list_head tasks; @@ -305,14 +365,15 @@ struct cgroup_base_stat { #ifdef CONFIG_SCHED_CORE u64 forceidle_sum; #endif + u64 ntime; }; /* * rstat - cgroup scalable recursive statistics. Accounting is done - * per-cpu in cgroup_rstat_cpu which is then lazily propagated up the + * per-cpu in css_rstat_cpu which is then lazily propagated up the * hierarchy on reads. * - * When a stat gets updated, the cgroup_rstat_cpu and its ancestors are + * When a stat gets updated, the css_rstat_cpu and its ancestors are * linked into the updated tree. On the following read, propagation only * considers and consumes the updated tree. This makes reading O(the * number of descendants which have been active since last read) instead of @@ -324,10 +385,26 @@ struct cgroup_base_stat { * frequency decreases the cost of each read. * * This struct hosts both the fields which implement the above - - * updated_children and updated_next - and the fields which track basic - * resource statistics on top of it - bsync, bstat and last_bstat. + * updated_children and updated_next. + */ +struct css_rstat_cpu { + /* + * Child cgroups with stat updates on this cpu since the last read + * are linked on the parent's ->updated_children through + * ->updated_next. updated_children is terminated by its container css. + */ + struct cgroup_subsys_state *updated_children; + struct cgroup_subsys_state *updated_next; /* NULL if not on the list */ + + struct llist_node lnode; /* lockless list for update */ + struct cgroup_subsys_state *owner; /* back pointer */ +}; + +/* + * This struct hosts the fields which track basic resource statistics on + * top of it - bsync, bstat and last_bstat. */ -struct cgroup_rstat_cpu { +struct cgroup_rstat_base_cpu { /* * ->bsync protects ->bstat. These are the only fields which get * updated in the hot path. @@ -342,18 +419,18 @@ struct cgroup_rstat_cpu { struct cgroup_base_stat last_bstat; /* - * Child cgroups with stat updates on this cpu since the last read - * are linked on the parent's ->updated_children through - * ->updated_next. - * - * In addition to being more compact, singly-linked list pointing - * to the cgroup makes it unnecessary for each per-cpu struct to - * point back to the associated cgroup. - * - * Protected by per-cpu cgroup_rstat_cpu_lock. + * This field is used to record the cumulative per-cpu time of + * the cgroup and its descendants. Currently it can be read via + * eBPF/drgn etc, and we are still trying to determine how to + * expose it in the cgroupfs interface. */ - struct cgroup *updated_children; /* terminated by self cgroup */ - struct cgroup *updated_next; /* NULL iff not on the list */ + struct cgroup_base_stat subtree_bstat; + + /* + * Snapshots at the last reading. These are used to calculate the + * deltas to propagate to the per-cpu subtree_bstat. + */ + struct cgroup_base_stat last_subtree_bstat; }; struct cgroup_freezer_state { @@ -361,7 +438,7 @@ struct cgroup_freezer_state { bool freeze; /* Should the cgroup actually be frozen? */ - int e_freeze; + bool e_freeze; /* Fields below are protected by css_set_lock */ @@ -373,6 +450,23 @@ struct cgroup_freezer_state { * frozen, SIGSTOPped, and PTRACEd. */ int nr_frozen_tasks; + + /* Freeze time data consistency protection */ + seqcount_spinlock_t freeze_seq; + + /* + * Most recent time the cgroup was requested to freeze. + * Accesses guarded by freeze_seq counter. Writes serialized + * by css_set_lock. + */ + u64 freeze_start_nsec; + + /* + * Total duration the cgroup has spent freezing. + * Accesses guarded by freeze_seq counter. Writes serialized + * by css_set_lock. + */ + u64 frozen_nsec; }; struct cgroup { @@ -424,6 +518,9 @@ struct cgroup { int nr_threaded_children; /* # of live threaded child cgroups */ + /* sequence number for cgroup.kill, serialized by css_set_lock. */ + unsigned int kill_seq; + struct kernfs_node *kn; /* cgroup kernfs entry */ struct cgroup_file procs_file; /* handle for "cgroup.procs" */ struct cgroup_file events_file; /* handle for "cgroup.events" */ @@ -446,6 +543,12 @@ struct cgroup { /* Private pointers for each registered subsystem */ struct cgroup_subsys_state __rcu *subsys[CGROUP_SUBSYS_COUNT]; + /* + * Keep track of total number of dying CSSes at and below this cgroup. + * Protected by cgroup_mutex. + */ + int nr_dying_subsys[CGROUP_SUBSYS_COUNT]; + struct cgroup_root *root; /* @@ -473,9 +576,23 @@ struct cgroup { struct cgroup *dom_cgrp; struct cgroup *old_dom_cgrp; /* used while enabling threaded */ - /* per-cpu recursive resource statistics */ - struct cgroup_rstat_cpu __percpu *rstat_cpu; - struct list_head rstat_css_list; + /* + * Depending on the context, this field is initialized via + * css_rstat_init() at different places: + * + * when cgroup is the root cgroup + * performed in cgroup_setup_root() + * otherwise + * performed in cgroup_create() + */ + struct cgroup_rstat_base_cpu __percpu *rstat_base_cpu; + + /* + * Add padding to keep the read mostly rstat per-cpu pointer on a + * different cacheline than the following *bstat fields which can have + * frequent updates. + */ + CACHELINE_PADDING(_pad_); /* cgroup basic resource statistics */ struct cgroup_base_stat last_bstat; @@ -501,9 +618,6 @@ struct cgroup { /* used to store eBPF programs */ struct cgroup_bpf bpf; - /* If there is block congestion on this cgroup. */ - atomic_t congestion_count; - /* Used to store internal freezer state */ struct cgroup_freezer_state freezer; @@ -529,6 +643,10 @@ struct cgroup_root { /* Unique id for this hierarchy. */ int hierarchy_id; + /* A list running through the active hierarchies */ + struct list_head root_list; + struct rcu_head rcu; /* Must be near the top */ + /* * The root cgroup. The containing cgroup_root will be destroyed on its * release. cgrp->ancestors[0] will be used overflowing into the @@ -542,9 +660,6 @@ struct cgroup_root { /* Number of cgroups in the hierarchy, used only for /proc/cgroups */ atomic_t nr_cgrps; - /* A list running through the active hierarchies */ - struct list_head root_list; - /* Hierarchy-specific flags */ unsigned int flags; @@ -564,9 +679,8 @@ struct cgroup_root { */ struct cftype { /* - * By convention, the name should begin with the name of the - * subsystem, followed by a period. Zero length string indicates - * end of cftype array. + * Name of the subsystem is prepended in cgroup_file_name(). + * Zero length string indicates end of cftype array. */ char name[MAX_CFTYPE_NAME]; unsigned long private; @@ -642,9 +756,7 @@ struct cftype { __poll_t (*poll)(struct kernfs_open_file *of, struct poll_table_struct *pt); -#ifdef CONFIG_DEBUG_LOCK_ALLOC struct lock_class_key lockdep_key; -#endif }; /* @@ -658,14 +770,16 @@ struct cgroup_subsys { void (*css_released)(struct cgroup_subsys_state *css); void (*css_free)(struct cgroup_subsys_state *css); void (*css_reset)(struct cgroup_subsys_state *css); + void (*css_killed)(struct cgroup_subsys_state *css); void (*css_rstat_flush)(struct cgroup_subsys_state *css, int cpu); int (*css_extra_stat_show)(struct seq_file *seq, struct cgroup_subsys_state *css); + int (*css_local_stat_show)(struct seq_file *seq, + struct cgroup_subsys_state *css); int (*can_attach)(struct cgroup_taskset *tset); void (*cancel_attach)(struct cgroup_taskset *tset); void (*attach)(struct cgroup_taskset *tset); - void (*post_attach)(void); int (*can_fork)(struct task_struct *task, struct css_set *cset); void (*cancel_fork)(struct task_struct *task, struct css_set *cset); @@ -735,20 +849,32 @@ struct cgroup_subsys { * specifies the mask of subsystems that this one depends on. */ unsigned int depends_on; + + spinlock_t rstat_ss_lock; + struct llist_head __percpu *lhead; /* lockless update list head */ }; extern struct percpu_rw_semaphore cgroup_threadgroup_rwsem; +extern bool cgroup_enable_per_threadgroup_rwsem; + +struct cgroup_of_peak { + unsigned long value; + struct list_head list; +}; /** * cgroup_threadgroup_change_begin - threadgroup exclusion for cgroups * @tsk: target task * * Allows cgroup operations to synchronize against threadgroup changes - * using a percpu_rw_semaphore. + * using a global percpu_rw_semaphore and a per threadgroup rw_semaphore when + * favordynmods is on. See the comment above CGRP_ROOT_FAVOR_DYNMODS definition. */ static inline void cgroup_threadgroup_change_begin(struct task_struct *tsk) { percpu_down_read(&cgroup_threadgroup_rwsem); + if (cgroup_enable_per_threadgroup_rwsem) + down_read(&tsk->signal->cgroup_threadgroup_rwsem); } /** @@ -759,6 +885,8 @@ static inline void cgroup_threadgroup_change_begin(struct task_struct *tsk) */ static inline void cgroup_threadgroup_change_end(struct task_struct *tsk) { + if (cgroup_enable_per_threadgroup_rwsem) + up_read(&tsk->signal->cgroup_threadgroup_rwsem); percpu_up_read(&cgroup_threadgroup_rwsem); } @@ -806,14 +934,12 @@ static inline u16 sock_cgroup_prioidx(const struct sock_cgroup_data *skcd) #endif } +#ifdef CONFIG_CGROUP_NET_CLASSID static inline u32 sock_cgroup_classid(const struct sock_cgroup_data *skcd) { -#ifdef CONFIG_CGROUP_NET_CLASSID return READ_ONCE(skcd->classid); -#else - return 0; -#endif } +#endif static inline void sock_cgroup_set_prioidx(struct sock_cgroup_data *skcd, u16 prioidx) @@ -823,13 +949,13 @@ static inline void sock_cgroup_set_prioidx(struct sock_cgroup_data *skcd, #endif } +#ifdef CONFIG_CGROUP_NET_CLASSID static inline void sock_cgroup_set_classid(struct sock_cgroup_data *skcd, u32 classid) { -#ifdef CONFIG_CGROUP_NET_CLASSID WRITE_ONCE(skcd->classid, classid); -#endif } +#endif #else /* CONFIG_SOCK_CGROUP_DATA */ |