diff options
Diffstat (limited to 'include/linux/cgroup.h')
| -rw-r--r-- | include/linux/cgroup.h | 129 |
1 files changed, 66 insertions, 63 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index eb7ca55f72ef..22e3754f89c5 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -13,10 +13,10 @@ #include <linux/nodemask.h> #include <linux/rculist.h> #include <linux/cgroupstats.h> -#include <linux/rwsem.h> #include <linux/fs.h> #include <linux/seq_file.h> #include <linux/kernfs.h> +#include <linux/jump_label.h> #include <linux/cgroup-defs.h> @@ -41,6 +41,10 @@ struct css_task_iter { struct list_head *task_pos; struct list_head *tasks_head; struct list_head *mg_tasks_head; + + struct css_set *cur_cset; + struct task_struct *cur_task; + struct list_head iters_node; /* css_set->task_iters */ }; extern struct cgroup_root cgrp_dfl_root; @@ -50,6 +54,26 @@ extern struct css_set init_css_set; #include <linux/cgroup_subsys.h> #undef SUBSYS +#define SUBSYS(_x) \ + extern struct static_key_true _x ## _cgrp_subsys_enabled_key; \ + extern struct static_key_true _x ## _cgrp_subsys_on_dfl_key; +#include <linux/cgroup_subsys.h> +#undef SUBSYS + +/** + * cgroup_subsys_enabled - fast test on whether a subsys is enabled + * @ss: subsystem in question + */ +#define cgroup_subsys_enabled(ss) \ + static_branch_likely(&ss ## _enabled_key) + +/** + * cgroup_subsys_on_dfl - fast test on whether a subsys is on default hierarchy + * @ss: subsystem in question + */ +#define cgroup_subsys_on_dfl(ss) \ + static_branch_likely(&ss ## _on_dfl_key) + bool css_has_online_children(struct cgroup_subsys_state *css); struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss); struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup, @@ -78,6 +102,7 @@ extern void cgroup_cancel_fork(struct task_struct *p, extern void cgroup_post_fork(struct task_struct *p, void *old_ss_priv[CGROUP_CANFORK_COUNT]); void cgroup_exit(struct task_struct *p); +void cgroup_free(struct task_struct *p); int cgroup_init_early(void); int cgroup_init(void); @@ -211,11 +236,33 @@ void css_task_iter_end(struct css_task_iter *it); * cgroup_taskset_for_each - iterate cgroup_taskset * @task: the loop cursor * @tset: taskset to iterate + * + * @tset may contain multiple tasks and they may belong to multiple + * processes. When there are multiple tasks in @tset, if a task of a + * process is in @tset, all tasks of the process are in @tset. Also, all + * are guaranteed to share the same source and destination csses. + * + * Iteration is not in any specific order. */ #define cgroup_taskset_for_each(task, tset) \ for ((task) = cgroup_taskset_first((tset)); (task); \ (task) = cgroup_taskset_next((tset))) +/** + * cgroup_taskset_for_each_leader - iterate group leaders in a cgroup_taskset + * @leader: the loop cursor + * @tset: takset to iterate + * + * Iterate threadgroup leaders of @tset. For single-task migrations, @tset + * may not contain any. + */ +#define cgroup_taskset_for_each_leader(leader, tset) \ + for ((leader) = cgroup_taskset_first((tset)); (leader); \ + (leader) = cgroup_taskset_next((tset))) \ + if ((leader) != (leader)->group_leader) \ + ; \ + else + /* * Inline functions. */ @@ -320,11 +367,11 @@ static inline void css_put_many(struct cgroup_subsys_state *css, unsigned int n) */ #ifdef CONFIG_PROVE_RCU extern struct mutex cgroup_mutex; -extern struct rw_semaphore css_set_rwsem; +extern spinlock_t css_set_lock; #define task_css_set_check(task, __c) \ rcu_dereference_check((task)->cgroups, \ lockdep_is_held(&cgroup_mutex) || \ - lockdep_is_held(&css_set_rwsem) || \ + lockdep_is_held(&css_set_lock) || \ ((task)->flags & PF_EXITING) || (__c)) #else #define task_css_set_check(task, __c) \ @@ -412,68 +459,10 @@ static inline struct cgroup *task_cgroup(struct task_struct *task, return task_css(task, subsys_id)->cgroup; } -/** - * cgroup_on_dfl - test whether a cgroup is on the default hierarchy - * @cgrp: the cgroup of interest - * - * The default hierarchy is the v2 interface of cgroup and this function - * can be used to test whether a cgroup is on the default hierarchy for - * cases where a subsystem should behave differnetly depending on the - * interface version. - * - * The set of behaviors which change on the default hierarchy are still - * being determined and the mount option is prefixed with __DEVEL__. - * - * List of changed behaviors: - * - * - Mount options "noprefix", "xattr", "clone_children", "release_agent" - * and "name" are disallowed. - * - * - When mounting an existing superblock, mount options should match. - * - * - Remount is disallowed. - * - * - rename(2) is disallowed. - * - * - "tasks" is removed. Everything should be at process granularity. Use - * "cgroup.procs" instead. - * - * - "cgroup.procs" is not sorted. pids will be unique unless they got - * recycled inbetween reads. - * - * - "release_agent" and "notify_on_release" are removed. Replacement - * notification mechanism will be implemented. - * - * - "cgroup.clone_children" is removed. - * - * - "cgroup.subtree_populated" is available. Its value is 0 if the cgroup - * and its descendants contain no task; otherwise, 1. The file also - * generates kernfs notification which can be monitored through poll and - * [di]notify when the value of the file changes. - * - * - cpuset: tasks will be kept in empty cpusets when hotplug happens and - * take masks of ancestors with non-empty cpus/mems, instead of being - * moved to an ancestor. - * - * - cpuset: a task can be moved into an empty cpuset, and again it takes - * masks of ancestors. - * - * - memcg: use_hierarchy is on by default and the cgroup file for the flag - * is not created. - * - * - blkcg: blk-throttle becomes properly hierarchical. - * - * - debug: disallowed on the default hierarchy. - */ -static inline bool cgroup_on_dfl(const struct cgroup *cgrp) -{ - return cgrp->root == &cgrp_dfl_root; -} - /* no synchronization, the result can only be used as a hint */ -static inline bool cgroup_has_tasks(struct cgroup *cgrp) +static inline bool cgroup_is_populated(struct cgroup *cgrp) { - return !list_empty(&cgrp->cset_links); + return cgrp->populated_cnt; } /* returns ino associated with a cgroup */ @@ -527,6 +516,19 @@ static inline void pr_cont_cgroup_path(struct cgroup *cgrp) pr_cont_kernfs_path(cgrp->kn); } +/** + * cgroup_file_notify - generate a file modified event for a cgroup_file + * @cfile: target cgroup_file + * + * @cfile must have been obtained by setting cftype->file_offset. + */ +static inline void cgroup_file_notify(struct cgroup_file *cfile) +{ + /* might not have been created due to one of the CFTYPE selector flags */ + if (cfile->kn) + kernfs_notify(cfile->kn); +} + #else /* !CONFIG_CGROUPS */ struct cgroup_subsys_state; @@ -546,6 +548,7 @@ static inline void cgroup_cancel_fork(struct task_struct *p, static inline void cgroup_post_fork(struct task_struct *p, void *ss_priv[CGROUP_CANFORK_COUNT]) {} static inline void cgroup_exit(struct task_struct *p) {} +static inline void cgroup_free(struct task_struct *p) {} static inline int cgroup_init_early(void) { return 0; } static inline int cgroup_init(void) { return 0; } |
