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authorLinus Torvalds <torvalds@linux-foundation.org>2014-05-21 18:36:40 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2014-05-21 18:36:40 +0900
commit06eb4cc2e7ad1b32a3b2580eff772c29b53a2cc6 (patch)
treec3e64d5ee6ffdf548c863bf64ec2aed704029fc3 /include
parent6ab9028d00da2ed34f46a72fa3271b04a402f1e1 (diff)
parent36e9d2ebcc15d029b33f42a36146ab5a5bcfcfe7 (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.h15
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)
{