diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2017-06-21 09:07:52 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2017-06-21 09:07:52 +0200 |
commit | f0cd9ae5d0df8668e76359a3e0e99856aa9c53b9 (patch) | |
tree | 84d3297b16fa7e373f2eabef56cd12ae5a9b8a29 /include/linux/cgroup.h | |
parent | 098b0e01a91c42aaaf0425605cd126b03fcb0bcf (diff) | |
parent | 8e6cec1c7c5afa489687c90be15d6ed82c742975 (diff) |
Merge branch 'timers/urgent' into timers/core
Pick up dependent changes.
Diffstat (limited to 'include/linux/cgroup.h')
-rw-r--r-- | include/linux/cgroup.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index ed2573e149fa..710a005c6b7a 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -344,6 +344,26 @@ static inline bool css_tryget_online(struct cgroup_subsys_state *css) } /** + * css_is_dying - test whether the specified css is dying + * @css: target css + * + * Test whether @css is in the process of offlining or already offline. In + * most cases, ->css_online() and ->css_offline() callbacks should be + * enough; however, the actual offline operations are RCU delayed and this + * test returns %true also when @css is scheduled to be offlined. + * + * This is useful, for example, when the use case requires synchronous + * behavior with respect to cgroup removal. cgroup removal schedules css + * offlining but the css can seem alive while the operation is being + * delayed. If the delay affects user visible semantics, this test can be + * used to resolve the situation. + */ +static inline bool css_is_dying(struct cgroup_subsys_state *css) +{ + return !(css->flags & CSS_NO_REF) && percpu_ref_is_dying(&css->refcnt); +} + +/** * css_put - put a css reference * @css: target css * |