memcg: mm_update_next_owner() should skip kthreads
"Search through everything else" in mm_update_next_owner() can hit a
kthread which adopted this "mm" via use_mm(), it should not be used as
mm->owner. Add the PF_KTHREAD check.
While at it, change this code to use for_each_process_thread() instead
of deprecated do_each_thread/while_each_thread.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Peter Chiang <pchiang@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/exit.c b/kernel/exit.c
index da1b838..5ac3c19 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -395,14 +395,12 @@
}
/*
- * Search through everything else. We should not get
- * here often
+ * Search through everything else, we should not get here often.
*/
- do_each_thread(g, c) {
- if (c->mm == mm)
+ for_each_process_thread(g, c) {
+ if (!(c->flags & PF_KTHREAD) && c->mm == mm)
goto assign_new_owner;
- } while_each_thread(g, c);
-
+ }
read_unlock(&tasklist_lock);
/*
* We found no owner yet mm_users > 1: this implies that we are