mm, memcg: move all oom handling to memcontrol.c

By globally defining check_panic_on_oom(), the memcg oom handler can be
moved entirely to mm/memcontrol.c.  This removes the ugly #ifdef in the
oom killer and cleans up the code.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/oom.h b/include/linux/oom.h
index 5dc0e384ae9e..49a3031fda50 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -61,6 +61,9 @@ extern void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
 extern int try_set_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_flags);
 extern void clear_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_flags);
 
+extern void check_panic_on_oom(enum oom_constraint constraint, gfp_t gfp_mask,
+                               int order, const nodemask_t *nodemask);
+
 extern enum oom_scan_t oom_scan_process_thread(struct task_struct *task,
                 unsigned long totalpages, const nodemask_t *nodemask,
                 bool force_kill);