From 2199ce7e00eed8ce884d49f0cb690477c5193ed7 Mon Sep 17 00:00:00 2001
From: Ben Blum <bblum@google.com>
Date: Wed, 23 Sep 2009 15:56:29 -0700
Subject: [PATCH] --- yaml --- r: 165661 b: refs/heads/master c:
 c378369d8b4fa516ff2b1e79c3eded4e0e955ebb h: refs/heads/master i:   165659:
 311e45381340764813e8fabdd2901ed49ffea0a0 v: v3

---
 [refs]                       | 2 +-
 trunk/include/linux/cgroup.h | 3 +++
 trunk/kernel/cgroup.c        | 8 +++++++-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 817bad33265f..311303477b26 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d1d9fd3308fdef6b4bf564fa3d6cfe35b68b50bc
+refs/heads/master: c378369d8b4fa516ff2b1e79c3eded4e0e955ebb
diff --git a/trunk/include/linux/cgroup.h b/trunk/include/linux/cgroup.h
index 88e863460726..3ac78a2f4b5a 100644
--- a/trunk/include/linux/cgroup.h
+++ b/trunk/include/linux/cgroup.h
@@ -260,6 +260,9 @@ struct css_set {
 	 * during subsystem registration (at boot time).
 	 */
 	struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT];
+
+	/* For RCU-protected deletion */
+	struct rcu_head rcu_head;
 };
 
 /*
diff --git a/trunk/kernel/cgroup.c b/trunk/kernel/cgroup.c
index 3e356b05b2d5..bf8dd1a9f2d1 100644
--- a/trunk/kernel/cgroup.c
+++ b/trunk/kernel/cgroup.c
@@ -267,6 +267,12 @@ static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[])
 	return &css_set_table[index];
 }
 
+static void free_css_set_rcu(struct rcu_head *obj)
+{
+	struct css_set *cg = container_of(obj, struct css_set, rcu_head);
+	kfree(cg);
+}
+
 /* We don't maintain the lists running through each css_set to its
  * task until after the first call to cgroup_iter_start(). This
  * reduces the fork()/exit() overhead for people who have cgroups
@@ -310,7 +316,7 @@ static void __put_css_set(struct css_set *cg, int taskexit)
 	}
 
 	write_unlock(&css_set_lock);
-	kfree(cg);
+	call_rcu(&cg->rcu_head, free_css_set_rcu);
 }
 
 /*