Merge branch 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

[sfrench/cifs-2.6.git] / kernel / cpuset.c

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index efbf9baf77ec8425c2d5d14a61afc5cf0e28b181..e2dbb60004d4f651b4fa6e53acbd788f11ef6fbe 100644 (file)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -948,12 +948,6 @@ 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
@@ -970,8 +964,10 @@ 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();
 }
 
 /*
@@ -2416,9 +2412,9 @@ int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
 
        rcu_read_lock();
        cs = nearest_hardwall_ancestor(task_cs(current));
+       allowed = node_isset(node, cs->mems_allowed);
        rcu_read_unlock();
 
-       allowed = node_isset(node, cs->mems_allowed);
        mutex_unlock(&callback_mutex);
        return allowed;
 }