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Commit ca62eec4 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 

Pull cgroup fixes from Tejun Heo:
 "Two cpuset locking fixes from Li.  Both tagged for -stable"

* 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cpuset: fix a race condition in __cpuset_node_allowed_softwall()
  cpuset: fix a locking issue in cpuset_migrate_mm()
parents 15b04859 99afb0fd

kernel/cpuset.c

+3 −7
Original line number Diff line number Diff line
@@ -974,12 +974,6 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, 
 *    Temporarilly set tasks mems_allowed to target nodes of migration,

 *    so that the migration code can allocate pages on these nodes.

 *

 *    Call holding cpuset_mutex, so current's cpuset won't change

 *    during this call, as manage_mutex holds off any cpuset_attach()

 *    calls.  Therefore we don't need to take task_lock around the

 *    call to guarantee_online_mems(), as we know no one is changing

 *    our task's cpuset.

 *

 *    While the mm_struct we are migrating is typically from some

 *    other task, the task_struct mems_allowed that we are hacking

 *    is for our current task, which must allocate new pages for that
@@ -996,8 +990,10 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from, 


	do_migrate_pages(mm, from, to, MPOL_MF_MOVE_ALL);



	rcu_read_lock();

	mems_cs = effective_nodemask_cpuset(task_cs(tsk));

	guarantee_online_mems(mems_cs, &tsk->mems_allowed);

	rcu_read_unlock();

}



/*
@@ -2486,9 +2482,9 @@ int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask) 


	task_lock(current);

	cs = nearest_hardwall_ancestor(task_cs(current));

	allowed = node_isset(node, cs->mems_allowed);

	task_unlock(current);



	allowed = node_isset(node, cs->mems_allowed);

	mutex_unlock(&callback_mutex);

	return allowed;

}