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authorTejun Heo <tj@kernel.org>2014-11-18 02:49:51 -0500
committerTejun Heo <tj@kernel.org>2014-11-18 02:49:51 -0500
commit7d172cc89b8589e4173d0c73a1ddaae408f29c9d (patch)
treeee1bb0594232895aaf2c5c6d604a2e4b8e2cbf4d
parentdb6e3053456800f0a7220b30355bece64764efe7 (diff)
downloadblackbird-op-linux-7d172cc89b8589e4173d0c73a1ddaae408f29c9d.tar.gz
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cgroup: add cgroup_subsys->css_released()
Add a new cgroup subsys callback css_released(). This is called when the reference count of the css (cgroup_subsys_state) reaches zero before RCU scheduling free. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Zefan Li <lizefan@huawei.com>
-rw-r--r--include/linux/cgroup.h1
-rw-r--r--kernel/cgroup.c2
2 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 1d5196889048..e717a39f22ea 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -612,6 +612,7 @@ struct cgroup_subsys {
struct cgroup_subsys_state *(*css_alloc)(struct cgroup_subsys_state *parent_css);
int (*css_online)(struct cgroup_subsys_state *css);
void (*css_offline)(struct cgroup_subsys_state *css);
+ void (*css_released)(struct cgroup_subsys_state *css);
void (*css_free)(struct cgroup_subsys_state *css);
void (*css_reset)(struct cgroup_subsys_state *css);
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index dffa54041d4a..c8558693102b 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4380,6 +4380,8 @@ static void css_release_work_fn(struct work_struct *work)
if (ss) {
/* css release path */
cgroup_idr_remove(&ss->css_idr, css->id);
+ if (ss->css_released)
+ ss->css_released(css);
} else {
/* cgroup release path */
cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id);
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