From: Li Zefan Date: Tue, 12 Mar 2013 02:28:39 +0000 (+0800) Subject: cpuset: fix RCU lockdep splat in cpuset_print_task_mems_allowed() X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=cfb5966bef85412dab9c93553db10b3e99ac32e8;p=linux-edison.git cpuset: fix RCU lockdep splat in cpuset_print_task_mems_allowed() Sasha reported a lockdep warning when OOM was triggered. The reason is cgroup_name() should be called with rcu_read_lock() held. Reported-by: Sasha Levin Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- diff --git a/kernel/cpuset.c b/kernel/cpuset.c index ace5bfcdcb3..efbfca7a33e 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2599,6 +2599,7 @@ void cpuset_print_task_mems_allowed(struct task_struct *tsk) struct cgroup *cgrp = task_cs(tsk)->css.cgroup; + rcu_read_lock(); spin_lock(&cpuset_buffer_lock); nodelist_scnprintf(cpuset_nodelist, CPUSET_NODELIST_LEN, @@ -2607,6 +2608,7 @@ void cpuset_print_task_mems_allowed(struct task_struct *tsk) tsk->comm, cgroup_name(cgrp), cpuset_nodelist); spin_unlock(&cpuset_buffer_lock); + rcu_read_unlock(); } /*