1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_CGROUP_H
3 #define _LINUX_CGROUP_H
7 * Copyright (C) 2003 BULL SA
8 * Copyright (C) 2004-2006 Silicon Graphics, Inc.
12 #include <linux/sched.h>
13 #include <linux/cpumask.h>
14 #include <linux/nodemask.h>
15 #include <linux/rculist.h>
16 #include <linux/cgroupstats.h>
18 #include <linux/seq_file.h>
19 #include <linux/kernfs.h>
20 #include <linux/jump_label.h>
21 #include <linux/types.h>
22 #include <linux/ns_common.h>
23 #include <linux/nsproxy.h>
24 #include <linux/user_namespace.h>
25 #include <linux/refcount.h>
26 #include <linux/kernel_stat.h>
28 #include <linux/cgroup-defs.h>
33 * All weight knobs on the default hierarhcy should use the following min,
34 * default and max values. The default value is the logarithmic center of
35 * MIN and MAX and allows 100x to be expressed in both directions.
37 #define CGROUP_WEIGHT_MIN 1
38 #define CGROUP_WEIGHT_DFL 100
39 #define CGROUP_WEIGHT_MAX 10000
41 /* walk only threadgroup leaders */
42 #define CSS_TASK_ITER_PROCS (1U << 0)
43 /* walk all threaded css_sets in the domain */
44 #define CSS_TASK_ITER_THREADED (1U << 1)
47 #define CSS_TASK_ITER_SKIPPED (1U << 16)
49 /* a css_task_iter should be treated as an opaque object */
50 struct css_task_iter
{
51 struct cgroup_subsys
*ss
;
54 struct list_head
*cset_pos
;
55 struct list_head
*cset_head
;
57 struct list_head
*tcset_pos
;
58 struct list_head
*tcset_head
;
60 struct list_head
*task_pos
;
61 struct list_head
*tasks_head
;
62 struct list_head
*mg_tasks_head
;
63 struct list_head
*dying_tasks_head
;
65 struct css_set
*cur_cset
;
66 struct css_set
*cur_dcset
;
67 struct task_struct
*cur_task
;
68 struct list_head iters_node
; /* css_set->task_iters */
71 extern struct cgroup_root cgrp_dfl_root
;
72 extern struct css_set init_css_set
;
74 #define SUBSYS(_x) extern struct cgroup_subsys _x ## _cgrp_subsys;
75 #include <linux/cgroup_subsys.h>
79 extern struct static_key_true _x ## _cgrp_subsys_enabled_key; \
80 extern struct static_key_true _x ## _cgrp_subsys_on_dfl_key;
81 #include <linux/cgroup_subsys.h>
85 * cgroup_subsys_enabled - fast test on whether a subsys is enabled
86 * @ss: subsystem in question
88 #define cgroup_subsys_enabled(ss) \
89 static_branch_likely(&ss ## _enabled_key)
92 * cgroup_subsys_on_dfl - fast test on whether a subsys is on default hierarchy
93 * @ss: subsystem in question
95 #define cgroup_subsys_on_dfl(ss) \
96 static_branch_likely(&ss ## _on_dfl_key)
98 bool css_has_online_children(struct cgroup_subsys_state
*css
);
99 struct cgroup_subsys_state
*css_from_id(int id
, struct cgroup_subsys
*ss
);
100 struct cgroup_subsys_state
*cgroup_e_css(struct cgroup
*cgroup
,
101 struct cgroup_subsys
*ss
);
102 struct cgroup_subsys_state
*cgroup_get_e_css(struct cgroup
*cgroup
,
103 struct cgroup_subsys
*ss
);
104 struct cgroup_subsys_state
*css_tryget_online_from_dir(struct dentry
*dentry
,
105 struct cgroup_subsys
*ss
);
107 struct cgroup
*cgroup_get_from_path(const char *path
);
108 struct cgroup
*cgroup_get_from_fd(int fd
);
110 int cgroup_attach_task_all(struct task_struct
*from
, struct task_struct
*);
111 int cgroup_transfer_tasks(struct cgroup
*to
, struct cgroup
*from
);
113 int cgroup_add_dfl_cftypes(struct cgroup_subsys
*ss
, struct cftype
*cfts
);
114 int cgroup_add_legacy_cftypes(struct cgroup_subsys
*ss
, struct cftype
*cfts
);
115 int cgroup_rm_cftypes(struct cftype
*cfts
);
116 void cgroup_file_notify(struct cgroup_file
*cfile
);
118 int task_cgroup_path(struct task_struct
*task
, char *buf
, size_t buflen
);
119 int cgroupstats_build(struct cgroupstats
*stats
, struct dentry
*dentry
);
120 int proc_cgroup_show(struct seq_file
*m
, struct pid_namespace
*ns
,
121 struct pid
*pid
, struct task_struct
*tsk
);
123 void cgroup_fork(struct task_struct
*p
);
124 extern int cgroup_can_fork(struct task_struct
*p
);
125 extern void cgroup_cancel_fork(struct task_struct
*p
);
126 extern void cgroup_post_fork(struct task_struct
*p
);
127 void cgroup_exit(struct task_struct
*p
);
128 void cgroup_release(struct task_struct
*p
);
129 void cgroup_free(struct task_struct
*p
);
131 int cgroup_init_early(void);
132 int cgroup_init(void);
135 * Iteration helpers and macros.
138 struct cgroup_subsys_state
*css_next_child(struct cgroup_subsys_state
*pos
,
139 struct cgroup_subsys_state
*parent
);
140 struct cgroup_subsys_state
*css_next_descendant_pre(struct cgroup_subsys_state
*pos
,
141 struct cgroup_subsys_state
*css
);
142 struct cgroup_subsys_state
*css_rightmost_descendant(struct cgroup_subsys_state
*pos
);
143 struct cgroup_subsys_state
*css_next_descendant_post(struct cgroup_subsys_state
*pos
,
144 struct cgroup_subsys_state
*css
);
146 struct task_struct
*cgroup_taskset_first(struct cgroup_taskset
*tset
,
147 struct cgroup_subsys_state
**dst_cssp
);
148 struct task_struct
*cgroup_taskset_next(struct cgroup_taskset
*tset
,
149 struct cgroup_subsys_state
**dst_cssp
);
151 void css_task_iter_start(struct cgroup_subsys_state
*css
, unsigned int flags
,
152 struct css_task_iter
*it
);
153 struct task_struct
*css_task_iter_next(struct css_task_iter
*it
);
154 void css_task_iter_end(struct css_task_iter
*it
);
157 * css_for_each_child - iterate through children of a css
158 * @pos: the css * to use as the loop cursor
159 * @parent: css whose children to walk
161 * Walk @parent's children. Must be called under rcu_read_lock().
163 * If a subsystem synchronizes ->css_online() and the start of iteration, a
164 * css which finished ->css_online() is guaranteed to be visible in the
165 * future iterations and will stay visible until the last reference is put.
166 * A css which hasn't finished ->css_online() or already finished
167 * ->css_offline() may show up during traversal. It's each subsystem's
168 * responsibility to synchronize against on/offlining.
170 * It is allowed to temporarily drop RCU read lock during iteration. The
171 * caller is responsible for ensuring that @pos remains accessible until
172 * the start of the next iteration by, for example, bumping the css refcnt.
174 #define css_for_each_child(pos, parent) \
175 for ((pos) = css_next_child(NULL, (parent)); (pos); \
176 (pos) = css_next_child((pos), (parent)))
179 * css_for_each_descendant_pre - pre-order walk of a css's descendants
180 * @pos: the css * to use as the loop cursor
181 * @root: css whose descendants to walk
183 * Walk @root's descendants. @root is included in the iteration and the
184 * first node to be visited. Must be called under rcu_read_lock().
186 * If a subsystem synchronizes ->css_online() and the start of iteration, a
187 * css which finished ->css_online() is guaranteed to be visible in the
188 * future iterations and will stay visible until the last reference is put.
189 * A css which hasn't finished ->css_online() or already finished
190 * ->css_offline() may show up during traversal. It's each subsystem's
191 * responsibility to synchronize against on/offlining.
193 * For example, the following guarantees that a descendant can't escape
194 * state updates of its ancestors.
198 * Lock @css's parent and @css;
199 * Inherit state from the parent;
203 * my_update_state(@css)
205 * css_for_each_descendant_pre(@pos, @css) {
208 * Update @css's state;
210 * Verify @pos is alive and inherit state from its parent;
215 * As long as the inheriting step, including checking the parent state, is
216 * enclosed inside @pos locking, double-locking the parent isn't necessary
217 * while inheriting. The state update to the parent is guaranteed to be
218 * visible by walking order and, as long as inheriting operations to the
219 * same @pos are atomic to each other, multiple updates racing each other
220 * still result in the correct state. It's guaranateed that at least one
221 * inheritance happens for any css after the latest update to its parent.
223 * If checking parent's state requires locking the parent, each inheriting
224 * iteration should lock and unlock both @pos->parent and @pos.
226 * Alternatively, a subsystem may choose to use a single global lock to
227 * synchronize ->css_online() and ->css_offline() against tree-walking
230 * It is allowed to temporarily drop RCU read lock during iteration. The
231 * caller is responsible for ensuring that @pos remains accessible until
232 * the start of the next iteration by, for example, bumping the css refcnt.
234 #define css_for_each_descendant_pre(pos, css) \
235 for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \
236 (pos) = css_next_descendant_pre((pos), (css)))
239 * css_for_each_descendant_post - post-order walk of a css's descendants
240 * @pos: the css * to use as the loop cursor
241 * @css: css whose descendants to walk
243 * Similar to css_for_each_descendant_pre() but performs post-order
244 * traversal instead. @root is included in the iteration and the last
245 * node to be visited.
247 * If a subsystem synchronizes ->css_online() and the start of iteration, a
248 * css which finished ->css_online() is guaranteed to be visible in the
249 * future iterations and will stay visible until the last reference is put.
250 * A css which hasn't finished ->css_online() or already finished
251 * ->css_offline() may show up during traversal. It's each subsystem's
252 * responsibility to synchronize against on/offlining.
254 * Note that the walk visibility guarantee example described in pre-order
255 * walk doesn't apply the same to post-order walks.
257 #define css_for_each_descendant_post(pos, css) \
258 for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \
259 (pos) = css_next_descendant_post((pos), (css)))
262 * cgroup_taskset_for_each - iterate cgroup_taskset
263 * @task: the loop cursor
264 * @dst_css: the destination css
265 * @tset: taskset to iterate
267 * @tset may contain multiple tasks and they may belong to multiple
270 * On the v2 hierarchy, there may be tasks from multiple processes and they
271 * may not share the source or destination csses.
273 * On traditional hierarchies, when there are multiple tasks in @tset, if a
274 * task of a process is in @tset, all tasks of the process are in @tset.
275 * Also, all are guaranteed to share the same source and destination csses.
277 * Iteration is not in any specific order.
279 #define cgroup_taskset_for_each(task, dst_css, tset) \
280 for ((task) = cgroup_taskset_first((tset), &(dst_css)); \
282 (task) = cgroup_taskset_next((tset), &(dst_css)))
285 * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset
286 * @leader: the loop cursor
287 * @dst_css: the destination css
288 * @tset: taskset to iterate
290 * Iterate threadgroup leaders of @tset. For single-task migrations, @tset
291 * may not contain any.
293 #define cgroup_taskset_for_each_leader(leader, dst_css, tset) \
294 for ((leader) = cgroup_taskset_first((tset), &(dst_css)); \
296 (leader) = cgroup_taskset_next((tset), &(dst_css))) \
297 if ((leader) != (leader)->group_leader) \
306 * css_get - obtain a reference on the specified css
309 * The caller must already have a reference.
311 static inline void css_get(struct cgroup_subsys_state
*css
)
313 if (!(css
->flags
& CSS_NO_REF
))
314 percpu_ref_get(&css
->refcnt
);
318 * css_get_many - obtain references on the specified css
320 * @n: number of references to get
322 * The caller must already have a reference.
324 static inline void css_get_many(struct cgroup_subsys_state
*css
, unsigned int n
)
326 if (!(css
->flags
& CSS_NO_REF
))
327 percpu_ref_get_many(&css
->refcnt
, n
);
331 * css_tryget - try to obtain a reference on the specified css
334 * Obtain a reference on @css unless it already has reached zero and is
335 * being released. This function doesn't care whether @css is on or
336 * offline. The caller naturally needs to ensure that @css is accessible
337 * but doesn't have to be holding a reference on it - IOW, RCU protected
338 * access is good enough for this function. Returns %true if a reference
339 * count was successfully obtained; %false otherwise.
341 static inline bool css_tryget(struct cgroup_subsys_state
*css
)
343 if (!(css
->flags
& CSS_NO_REF
))
344 return percpu_ref_tryget(&css
->refcnt
);
349 * css_tryget_online - try to obtain a reference on the specified css if online
352 * Obtain a reference on @css if it's online. The caller naturally needs
353 * to ensure that @css is accessible but doesn't have to be holding a
354 * reference on it - IOW, RCU protected access is good enough for this
355 * function. Returns %true if a reference count was successfully obtained;
358 static inline bool css_tryget_online(struct cgroup_subsys_state
*css
)
360 if (!(css
->flags
& CSS_NO_REF
))
361 return percpu_ref_tryget_live(&css
->refcnt
);
366 * css_is_dying - test whether the specified css is dying
369 * Test whether @css is in the process of offlining or already offline. In
370 * most cases, ->css_online() and ->css_offline() callbacks should be
371 * enough; however, the actual offline operations are RCU delayed and this
372 * test returns %true also when @css is scheduled to be offlined.
374 * This is useful, for example, when the use case requires synchronous
375 * behavior with respect to cgroup removal. cgroup removal schedules css
376 * offlining but the css can seem alive while the operation is being
377 * delayed. If the delay affects user visible semantics, this test can be
378 * used to resolve the situation.
380 static inline bool css_is_dying(struct cgroup_subsys_state
*css
)
382 return !(css
->flags
& CSS_NO_REF
) && percpu_ref_is_dying(&css
->refcnt
);
386 * css_put - put a css reference
389 * Put a reference obtained via css_get() and css_tryget_online().
391 static inline void css_put(struct cgroup_subsys_state
*css
)
393 if (!(css
->flags
& CSS_NO_REF
))
394 percpu_ref_put(&css
->refcnt
);
398 * css_put_many - put css references
400 * @n: number of references to put
402 * Put references obtained via css_get() and css_tryget_online().
404 static inline void css_put_many(struct cgroup_subsys_state
*css
, unsigned int n
)
406 if (!(css
->flags
& CSS_NO_REF
))
407 percpu_ref_put_many(&css
->refcnt
, n
);
410 static inline void cgroup_get(struct cgroup
*cgrp
)
412 css_get(&cgrp
->self
);
415 static inline bool cgroup_tryget(struct cgroup
*cgrp
)
417 return css_tryget(&cgrp
->self
);
420 static inline void cgroup_put(struct cgroup
*cgrp
)
422 css_put(&cgrp
->self
);
426 * task_css_set_check - obtain a task's css_set with extra access conditions
427 * @task: the task to obtain css_set for
428 * @__c: extra condition expression to be passed to rcu_dereference_check()
430 * A task's css_set is RCU protected, initialized and exited while holding
431 * task_lock(), and can only be modified while holding both cgroup_mutex
432 * and task_lock() while the task is alive. This macro verifies that the
433 * caller is inside proper critical section and returns @task's css_set.
435 * The caller can also specify additional allowed conditions via @__c, such
436 * as locks used during the cgroup_subsys::attach() methods.
438 #ifdef CONFIG_PROVE_RCU
439 extern struct mutex cgroup_mutex
;
440 extern spinlock_t css_set_lock
;
441 #define task_css_set_check(task, __c) \
442 rcu_dereference_check((task)->cgroups, \
443 lockdep_is_held(&cgroup_mutex) || \
444 lockdep_is_held(&css_set_lock) || \
445 ((task)->flags & PF_EXITING) || (__c))
447 #define task_css_set_check(task, __c) \
448 rcu_dereference((task)->cgroups)
452 * task_css_check - obtain css for (task, subsys) w/ extra access conds
453 * @task: the target task
454 * @subsys_id: the target subsystem ID
455 * @__c: extra condition expression to be passed to rcu_dereference_check()
457 * Return the cgroup_subsys_state for the (@task, @subsys_id) pair. The
458 * synchronization rules are the same as task_css_set_check().
460 #define task_css_check(task, subsys_id, __c) \
461 task_css_set_check((task), (__c))->subsys[(subsys_id)]
464 * task_css_set - obtain a task's css_set
465 * @task: the task to obtain css_set for
467 * See task_css_set_check().
469 static inline struct css_set
*task_css_set(struct task_struct
*task
)
471 return task_css_set_check(task
, false);
475 * task_css - obtain css for (task, subsys)
476 * @task: the target task
477 * @subsys_id: the target subsystem ID
479 * See task_css_check().
481 static inline struct cgroup_subsys_state
*task_css(struct task_struct
*task
,
484 return task_css_check(task
, subsys_id
, false);
488 * task_get_css - find and get the css for (task, subsys)
489 * @task: the target task
490 * @subsys_id: the target subsystem ID
492 * Find the css for the (@task, @subsys_id) combination, increment a
493 * reference on and return it. This function is guaranteed to return a
494 * valid css. The returned css may already have been offlined.
496 static inline struct cgroup_subsys_state
*
497 task_get_css(struct task_struct
*task
, int subsys_id
)
499 struct cgroup_subsys_state
*css
;
503 css
= task_css(task
, subsys_id
);
505 * Can't use css_tryget_online() here. A task which has
506 * PF_EXITING set may stay associated with an offline css.
507 * If such task calls this function, css_tryget_online()
510 if (likely(css_tryget(css
)))
519 * task_css_is_root - test whether a task belongs to the root css
520 * @task: the target task
521 * @subsys_id: the target subsystem ID
523 * Test whether @task belongs to the root css on the specified subsystem.
524 * May be invoked in any context.
526 static inline bool task_css_is_root(struct task_struct
*task
, int subsys_id
)
528 return task_css_check(task
, subsys_id
, true) ==
529 init_css_set
.subsys
[subsys_id
];
532 static inline struct cgroup
*task_cgroup(struct task_struct
*task
,
535 return task_css(task
, subsys_id
)->cgroup
;
538 static inline struct cgroup
*task_dfl_cgroup(struct task_struct
*task
)
540 return task_css_set(task
)->dfl_cgrp
;
543 static inline struct cgroup
*cgroup_parent(struct cgroup
*cgrp
)
545 struct cgroup_subsys_state
*parent_css
= cgrp
->self
.parent
;
548 return container_of(parent_css
, struct cgroup
, self
);
553 * cgroup_is_descendant - test ancestry
554 * @cgrp: the cgroup to be tested
555 * @ancestor: possible ancestor of @cgrp
557 * Test whether @cgrp is a descendant of @ancestor. It also returns %true
558 * if @cgrp == @ancestor. This function is safe to call as long as @cgrp
559 * and @ancestor are accessible.
561 static inline bool cgroup_is_descendant(struct cgroup
*cgrp
,
562 struct cgroup
*ancestor
)
564 if (cgrp
->root
!= ancestor
->root
|| cgrp
->level
< ancestor
->level
)
566 return cgrp
->ancestor_ids
[ancestor
->level
] == ancestor
->id
;
570 * cgroup_ancestor - find ancestor of cgroup
571 * @cgrp: cgroup to find ancestor of
572 * @ancestor_level: level of ancestor to find starting from root
574 * Find ancestor of cgroup at specified level starting from root if it exists
575 * and return pointer to it. Return NULL if @cgrp doesn't have ancestor at
578 * This function is safe to call as long as @cgrp is accessible.
580 static inline struct cgroup
*cgroup_ancestor(struct cgroup
*cgrp
,
583 if (cgrp
->level
< ancestor_level
)
585 while (cgrp
&& cgrp
->level
> ancestor_level
)
586 cgrp
= cgroup_parent(cgrp
);
591 * task_under_cgroup_hierarchy - test task's membership of cgroup ancestry
592 * @task: the task to be tested
593 * @ancestor: possible ancestor of @task's cgroup
595 * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor.
596 * It follows all the same rules as cgroup_is_descendant, and only applies
597 * to the default hierarchy.
599 static inline bool task_under_cgroup_hierarchy(struct task_struct
*task
,
600 struct cgroup
*ancestor
)
602 struct css_set
*cset
= task_css_set(task
);
604 return cgroup_is_descendant(cset
->dfl_cgrp
, ancestor
);
607 /* no synchronization, the result can only be used as a hint */
608 static inline bool cgroup_is_populated(struct cgroup
*cgrp
)
610 return cgrp
->nr_populated_csets
+ cgrp
->nr_populated_domain_children
+
611 cgrp
->nr_populated_threaded_children
;
614 /* returns ino associated with a cgroup */
615 static inline ino_t
cgroup_ino(struct cgroup
*cgrp
)
617 return cgrp
->kn
->id
.ino
;
620 /* cft/css accessors for cftype->write() operation */
621 static inline struct cftype
*of_cft(struct kernfs_open_file
*of
)
626 struct cgroup_subsys_state
*of_css(struct kernfs_open_file
*of
);
628 /* cft/css accessors for cftype->seq_*() operations */
629 static inline struct cftype
*seq_cft(struct seq_file
*seq
)
631 return of_cft(seq
->private);
634 static inline struct cgroup_subsys_state
*seq_css(struct seq_file
*seq
)
636 return of_css(seq
->private);
640 * Name / path handling functions. All are thin wrappers around the kernfs
641 * counterparts and can be called under any context.
644 static inline int cgroup_name(struct cgroup
*cgrp
, char *buf
, size_t buflen
)
646 return kernfs_name(cgrp
->kn
, buf
, buflen
);
649 static inline int cgroup_path(struct cgroup
*cgrp
, char *buf
, size_t buflen
)
651 return kernfs_path(cgrp
->kn
, buf
, buflen
);
654 static inline void pr_cont_cgroup_name(struct cgroup
*cgrp
)
656 pr_cont_kernfs_name(cgrp
->kn
);
659 static inline void pr_cont_cgroup_path(struct cgroup
*cgrp
)
661 pr_cont_kernfs_path(cgrp
->kn
);
664 static inline struct psi_group
*cgroup_psi(struct cgroup
*cgrp
)
669 static inline void cgroup_init_kthreadd(void)
672 * kthreadd is inherited by all kthreads, keep it in the root so
673 * that the new kthreads are guaranteed to stay in the root until
674 * initialization is finished.
676 current
->no_cgroup_migration
= 1;
679 static inline void cgroup_kthread_ready(void)
682 * This kthread finished initialization. The creator should have
683 * set PF_NO_SETAFFINITY if this kthread should stay in the root.
685 current
->no_cgroup_migration
= 0;
688 static inline union kernfs_node_id
*cgroup_get_kernfs_id(struct cgroup
*cgrp
)
690 return &cgrp
->kn
->id
;
693 void cgroup_path_from_kernfs_id(const union kernfs_node_id
*id
,
694 char *buf
, size_t buflen
);
695 #else /* !CONFIG_CGROUPS */
697 struct cgroup_subsys_state
;
700 static inline void css_put(struct cgroup_subsys_state
*css
) {}
701 static inline int cgroup_attach_task_all(struct task_struct
*from
,
702 struct task_struct
*t
) { return 0; }
703 static inline int cgroupstats_build(struct cgroupstats
*stats
,
704 struct dentry
*dentry
) { return -EINVAL
; }
706 static inline void cgroup_fork(struct task_struct
*p
) {}
707 static inline int cgroup_can_fork(struct task_struct
*p
) { return 0; }
708 static inline void cgroup_cancel_fork(struct task_struct
*p
) {}
709 static inline void cgroup_post_fork(struct task_struct
*p
) {}
710 static inline void cgroup_exit(struct task_struct
*p
) {}
711 static inline void cgroup_release(struct task_struct
*p
) {}
712 static inline void cgroup_free(struct task_struct
*p
) {}
714 static inline int cgroup_init_early(void) { return 0; }
715 static inline int cgroup_init(void) { return 0; }
716 static inline void cgroup_init_kthreadd(void) {}
717 static inline void cgroup_kthread_ready(void) {}
718 static inline union kernfs_node_id
*cgroup_get_kernfs_id(struct cgroup
*cgrp
)
723 static inline struct cgroup
*cgroup_parent(struct cgroup
*cgrp
)
728 static inline struct psi_group
*cgroup_psi(struct cgroup
*cgrp
)
733 static inline bool task_under_cgroup_hierarchy(struct task_struct
*task
,
734 struct cgroup
*ancestor
)
739 static inline void cgroup_path_from_kernfs_id(const union kernfs_node_id
*id
,
740 char *buf
, size_t buflen
) {}
741 #endif /* !CONFIG_CGROUPS */
743 #ifdef CONFIG_CGROUPS
745 * cgroup scalable recursive statistics.
747 void cgroup_rstat_updated(struct cgroup
*cgrp
, int cpu
);
748 void cgroup_rstat_flush(struct cgroup
*cgrp
);
749 void cgroup_rstat_flush_irqsafe(struct cgroup
*cgrp
);
750 void cgroup_rstat_flush_hold(struct cgroup
*cgrp
);
751 void cgroup_rstat_flush_release(void);
754 * Basic resource stats.
756 #ifdef CONFIG_CGROUP_CPUACCT
757 void cpuacct_charge(struct task_struct
*tsk
, u64 cputime
);
758 void cpuacct_account_field(struct task_struct
*tsk
, int index
, u64 val
);
760 static inline void cpuacct_charge(struct task_struct
*tsk
, u64 cputime
) {}
761 static inline void cpuacct_account_field(struct task_struct
*tsk
, int index
,
765 void __cgroup_account_cputime(struct cgroup
*cgrp
, u64 delta_exec
);
766 void __cgroup_account_cputime_field(struct cgroup
*cgrp
,
767 enum cpu_usage_stat index
, u64 delta_exec
);
769 static inline void cgroup_account_cputime(struct task_struct
*task
,
774 cpuacct_charge(task
, delta_exec
);
777 cgrp
= task_dfl_cgroup(task
);
778 if (cgroup_parent(cgrp
))
779 __cgroup_account_cputime(cgrp
, delta_exec
);
783 static inline void cgroup_account_cputime_field(struct task_struct
*task
,
784 enum cpu_usage_stat index
,
789 cpuacct_account_field(task
, index
, delta_exec
);
792 cgrp
= task_dfl_cgroup(task
);
793 if (cgroup_parent(cgrp
))
794 __cgroup_account_cputime_field(cgrp
, index
, delta_exec
);
798 #else /* CONFIG_CGROUPS */
800 static inline void cgroup_account_cputime(struct task_struct
*task
,
802 static inline void cgroup_account_cputime_field(struct task_struct
*task
,
803 enum cpu_usage_stat index
,
806 #endif /* CONFIG_CGROUPS */
809 * sock->sk_cgrp_data handling. For more info, see sock_cgroup_data
810 * definition in cgroup-defs.h.
812 #ifdef CONFIG_SOCK_CGROUP_DATA
814 #if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID)
815 extern spinlock_t cgroup_sk_update_lock
;
818 void cgroup_sk_alloc_disable(void);
819 void cgroup_sk_alloc(struct sock_cgroup_data
*skcd
);
820 void cgroup_sk_free(struct sock_cgroup_data
*skcd
);
822 static inline struct cgroup
*sock_cgroup_ptr(struct sock_cgroup_data
*skcd
)
824 #if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID)
828 * @skcd->val is 64bit but the following is safe on 32bit too as we
829 * just need the lower ulong to be written and read atomically.
831 v
= READ_ONCE(skcd
->val
);
834 return &cgrp_dfl_root
.cgrp
;
836 return (struct cgroup
*)(unsigned long)v
?: &cgrp_dfl_root
.cgrp
;
838 return (struct cgroup
*)(unsigned long)skcd
->val
;
842 #else /* CONFIG_CGROUP_DATA */
844 static inline void cgroup_sk_alloc(struct sock_cgroup_data
*skcd
) {}
845 static inline void cgroup_sk_free(struct sock_cgroup_data
*skcd
) {}
847 #endif /* CONFIG_CGROUP_DATA */
849 struct cgroup_namespace
{
852 struct user_namespace
*user_ns
;
853 struct ucounts
*ucounts
;
854 struct css_set
*root_cset
;
857 extern struct cgroup_namespace init_cgroup_ns
;
859 #ifdef CONFIG_CGROUPS
861 void free_cgroup_ns(struct cgroup_namespace
*ns
);
863 struct cgroup_namespace
*copy_cgroup_ns(unsigned long flags
,
864 struct user_namespace
*user_ns
,
865 struct cgroup_namespace
*old_ns
);
867 int cgroup_path_ns(struct cgroup
*cgrp
, char *buf
, size_t buflen
,
868 struct cgroup_namespace
*ns
);
870 #else /* !CONFIG_CGROUPS */
872 static inline void free_cgroup_ns(struct cgroup_namespace
*ns
) { }
873 static inline struct cgroup_namespace
*
874 copy_cgroup_ns(unsigned long flags
, struct user_namespace
*user_ns
,
875 struct cgroup_namespace
*old_ns
)
880 #endif /* !CONFIG_CGROUPS */
882 static inline void get_cgroup_ns(struct cgroup_namespace
*ns
)
885 refcount_inc(&ns
->count
);
888 static inline void put_cgroup_ns(struct cgroup_namespace
*ns
)
890 if (ns
&& refcount_dec_and_test(&ns
->count
))
894 #ifdef CONFIG_CGROUPS
896 void cgroup_enter_frozen(void);
897 void cgroup_leave_frozen(bool always_leave
);
898 void cgroup_update_frozen(struct cgroup
*cgrp
);
899 void cgroup_freeze(struct cgroup
*cgrp
, bool freeze
);
900 void cgroup_freezer_migrate_task(struct task_struct
*task
, struct cgroup
*src
,
903 static inline bool cgroup_task_freeze(struct task_struct
*task
)
907 if (task
->flags
& PF_KTHREAD
)
911 ret
= test_bit(CGRP_FREEZE
, &task_dfl_cgroup(task
)->flags
);
917 static inline bool cgroup_task_frozen(struct task_struct
*task
)
922 #else /* !CONFIG_CGROUPS */
924 static inline void cgroup_enter_frozen(void) { }
925 static inline void cgroup_leave_frozen(bool always_leave
) { }
926 static inline bool cgroup_task_freeze(struct task_struct
*task
)
930 static inline bool cgroup_task_frozen(struct task_struct
*task
)
935 #endif /* !CONFIG_CGROUPS */
937 #endif /* _LINUX_CGROUP_H */