diff options
Diffstat (limited to 'include/linux/cgroup.h')
| -rw-r--r-- | include/linux/cgroup.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index b76999954beb..4afe544d3547 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -113,6 +113,24 @@ static inline void css_get(struct cgroup_subsys_state *css) } /** + * css_tryget - try to obtain a reference on the specified css + * @css: target css + * + * Obtain a reference on @css unless it already has reached zero and is + * being released. This function doesn't care whether @css is on or + * offline. The caller naturally needs to ensure that @css is accessible + * but doesn't have to be holding a reference on it - IOW, RCU protected + * access is good enough for this function. Returns %true if a reference + * count was successfully obtained; %false otherwise. + */ +static inline bool css_tryget(struct cgroup_subsys_state *css) +{ + if (!(css->flags & CSS_NO_REF)) + return percpu_ref_tryget(&css->refcnt); + return true; +} + +/** * css_tryget_online - try to obtain a reference on the specified css if online * @css: target css * |