[PATCH] PM: Use WQ_MEM_RECLAIM flag for PM workqueue

[ravisankarreddylingareddy@gmail.com]

Deadlock is seen under below high memory usage scenario.

kswapd waiting to reclaim memory is blocked on i/o kworker and pm_wq
context which needs to wakeup i/o kworker is waiting for kthread
creation which is again blocked in memory reclaim path.

Use WQ_MEM_RECLAIM flag for PM workqueue to avoid this deadlock.

Signed-off-by: Ravisankar Reddy (Sony) <ravisankarreddylingareddy@gmail.com>
---
 kernel/power/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/power/main.c b/kernel/power/main.c
index 40f86ec4ab30..ff5f3349e76f 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -933,7 +933,7 @@ EXPORT_SYMBOL_GPL(pm_wq);
 
 static int __init pm_start_workqueue(void)
 {
-	pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
+	pm_wq = alloc_workqueue("pm", WQ_FREEZABLE | WQ_MEM_RECLAIM, 0);
 
 	return pm_wq ? 0 : -ENOMEM;
 }
-- 
2.17.1