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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-05-21 18:36:40 +0900 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-05-21 18:36:40 +0900 |
| commit | 06eb4cc2e7ad1b32a3b2580eff772c29b53a2cc6 (patch) | |
| tree | c3e64d5ee6ffdf548c863bf64ec2aed704029fc3 /include | |
| parent | 6ab9028d00da2ed34f46a72fa3271b04a402f1e1 (diff) | |
| parent | 36e9d2ebcc15d029b33f42a36146ab5a5bcfcfe7 (diff) | |
Merge branch 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull more cgroup fixes from Tejun Heo:
"Three more patches to fix cgroup_freezer breakage due to the recent
cgroup internal locking changes - an operation cgroup_freezer was
using now requires sleepable context and cgroup_freezer was invoking
that while holding a spin lock. cgroup_freezer was using an overly
elaborate hierarchical locking scheme.
While it's possible to convert the hierarchical spinlocks directly to
mutexes, this patch simplifies the overall locking so that it uses a
global mutex. This has the added benefit of avoiding iterating
potentially huge number of tasks under a spinlock. While the patch is
on the larger side in the devel cycle, the changes made are mostly
straight-forward and the locking logic is a lot simpler afterwards"
* 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: fix rcu_read_lock() leak in update_if_frozen()
cgroup_freezer: replace freezer->lock with freezer_mutex
cgroup: introduce task_css_is_root()
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/cgroup.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index c2515851c1aa..d60904b9e505 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -473,6 +473,7 @@ struct cftype { }; extern struct cgroup_root cgrp_dfl_root; +extern struct css_set init_css_set; static inline bool cgroup_on_dfl(const struct cgroup *cgrp) { @@ -700,6 +701,20 @@ static inline struct cgroup_subsys_state *task_css(struct task_struct *task, return task_css_check(task, subsys_id, false); } +/** + * task_css_is_root - test whether a task belongs to the root css + * @task: the target task + * @subsys_id: the target subsystem ID + * + * Test whether @task belongs to the root css on the specified subsystem. + * May be invoked in any context. + */ +static inline bool task_css_is_root(struct task_struct *task, int subsys_id) +{ + return task_css_check(task, subsys_id, true) == + init_css_set.subsys[subsys_id]; +} + static inline struct cgroup *task_cgroup(struct task_struct *task, int subsys_id) { |