+ cgroup-css-id-support-remove-rcu_read_lock-from-css_get_next.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     cgroup: remove rcu_read_lock() from css_get_next()
has been added to the -mm tree.  Its filename is
     cgroup-css-id-support-remove-rcu_read_lock-from-css_get_next.patch

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------------------------------------------------------
Subject: cgroup: remove rcu_read_lock() from css_get_next()
From: Bharata B Rao <bharata@linux.vnet.ibm.com>

Callers of css_get_next() are already calling css_get_next() under
rcu_read_lock() and hence there there is no need for css_get_next() to
re-acquire rcu_read_lock().  As per the comments in css_get_next(), let
the callers accquire the rcu_read_lock().

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/cgroup.c |    3 ---
 1 file changed, 3 deletions(-)

diff -puN kernel/cgroup.c~cgroup-css-id-support-remove-rcu_read_lock-from-css_get_next kernel/cgroup.c
--- a/kernel/cgroup.c~cgroup-css-id-support-remove-rcu_read_lock-from-css_get_next
+++ a/kernel/cgroup.c
@@ -3500,7 +3500,6 @@ css_get_next(struct cgroup_subsys *ss, i
 		return NULL;
 
 	BUG_ON(!ss->use_id);
-	rcu_read_lock();
 	/* fill start point for scan */
 	tmpid = id;
 	while (1) {
@@ -3524,8 +3523,6 @@ css_get_next(struct cgroup_subsys *ss, i
 		/* continue to scan from next id */
 		tmpid = tmpid + 1;
 	}