cgroup: use a per-cgroup work for release agent

Instead of using a global work to schedule release agent on removable
cgroups, we change to use a per-cgroup work to do this, which makes
the code much simpler.

v2: use a dedicated work instead of reusing css->destroy_work. (Tejun)

Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 3 insertions, 7 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index f7898e0bce1e..51958d0fb88f 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -234,13 +234,6 @@ struct cgroup {
         struct list_head e_csets[CGROUP_SUBSYS_COUNT];
 
         /*
-         * Linked list running through all cgroups that can
-         * potentially be reaped by the release agent. Protected by
-         * release_list_lock
-         */
-        struct list_head release_list;
-
-        /*
          * list of pidlists, up to two for each namespace (one for procs, one
          * for tasks); created on demand.
          */
@@ -249,6 +242,9 @@ struct cgroup {
 
         /* used to wait for offlining of csses */
         wait_queue_head_t offline_waitq;
+
+        /* used to schedule release agent */
+        struct work_struct release_agent_work;
 };
 
 #define MAX_CGROUP_ROOT_NAMELEN 64