From d5b1fe68baa7213f198e5be8cd1a1037258ab2c8 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 28 Dec 2012 13:18:28 -0800 Subject: cgroup: remove unused dummy cgroup_fork_callbacks() 5edee61ede ("cgroup: cgroup_subsys->fork() should be called after the task is added to css_set") removed cgroup_fork_callbacks() but forgot to remove its dummy version for !CONFIG_CGROUPS. Remove it. Signed-off-by: Tejun Heo Reported-by: Herton Ronaldo Krzesinski --- include/linux/cgroup.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 7d73905dcba2..942e68705577 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -706,7 +706,6 @@ struct cgroup_subsys_state *cgroup_css_from_dir(struct file *f, int id); static inline int cgroup_init_early(void) { return 0; } static inline int cgroup_init(void) { return 0; } static inline void cgroup_fork(struct task_struct *p) {} -static inline void cgroup_fork_callbacks(struct task_struct *p) {} static inline void cgroup_post_fork(struct task_struct *p) {} static inline void cgroup_exit(struct task_struct *p, int callbacks) {} -- cgit From 12a9d2fef1d35770d3cdc2cd1faabb83c45bc0fa Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 7 Jan 2013 08:49:33 -0800 Subject: cgroup: implement cgroup_rightmost_descendant() Implement cgroup_rightmost_descendant() which returns the right most descendant of the specified cgroup. This can be used to skip the cgroup's subtree while iterating with cgroup_for_each_descendant_pre(). Signed-off-by: Tejun Heo Acked-by: Michal Hocko Acked-by: Li Zefan --- include/linux/cgroup.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 942e68705577..8118a3120378 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -558,6 +558,7 @@ static inline struct cgroup* task_cgroup(struct task_struct *task, struct cgroup *cgroup_next_descendant_pre(struct cgroup *pos, struct cgroup *cgroup); +struct cgroup *cgroup_rightmost_descendant(struct cgroup *pos); /** * cgroup_for_each_descendant_pre - pre-order walk of a cgroup's descendants -- cgit From ace783b9bbfa2182b4a561498db3f09a0c56bc79 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 24 Jan 2013 14:30:48 +0800 Subject: sched: split out css_online/css_offline from tg creation/destruction This is a preparaton for later patches. - What do we gain from cpu_cgroup_css_online(): After ss->css_alloc() and before ss->css_online(), there's a small window that tg->css.cgroup is NULL. With this change, tg won't be seen before ss->css_online(), where it's added to the global list, so we're guaranteed we'll never see NULL tg->css.cgroup. - What do we gain from cpu_cgroup_css_offline(): tg is freed via RCU, so is cgroup. Without this change, This is how synchronization works: cgroup_rmdir() no ss->css_offline() diput() syncornize_rcu() ss->css_free() <-- unregister tg, and free it via call_rcu() kfree_rcu(cgroup) <-- wait possible refs to cgroup, and free cgroup We can't just kfree(cgroup), because tg might access tg->css.cgroup. With this change: cgroup_rmdir() ss->css_offline() <-- unregister tg diput() synchronize_rcu() <-- wait possible refs to tg and cgroup ss->css_free() <-- free tg kfree_rcu(cgroup) <-- free cgroup As you see, kfree_rcu() is redundant now. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo Acked-by: Ingo Molnar --- include/linux/sched.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 206bb089c06b..577eb973de7a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2750,7 +2750,10 @@ extern void normalize_rt_tasks(void); extern struct task_group root_task_group; extern struct task_group *sched_create_group(struct task_group *parent); +extern void sched_online_group(struct task_group *tg, + struct task_group *parent); extern void sched_destroy_group(struct task_group *tg); +extern void sched_offline_group(struct task_group *tg); extern void sched_move_task(struct task_struct *tsk); #ifdef CONFIG_FAIR_GROUP_SCHED extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); -- cgit From be44562613851235d801d41d5b3976dc4333f622 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 24 Jan 2013 14:31:42 +0800 Subject: cgroup: remove synchronize_rcu() from cgroup_diput() Free cgroup via call_rcu(). The actual work is done through workqueue. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- include/linux/cgroup.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 8118a3120378..900af5964f55 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -203,6 +203,7 @@ struct cgroup { /* For RCU-protected deletion */ struct rcu_head rcu_head; + struct work_struct free_work; /* List of events which userspace want to receive */ struct list_head event_list; -- cgit