mm-avoid-livelock-on-__gfp_fs-allocations-fix

augment comment

Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Colin Cross <ccross@android.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d768e40d2f160abd4800ac8654b2c40721efa563..a150e5a7a6ab1bf4d7d7a92854bcc7efcf896da3 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2263,9 +2263,10 @@ rebalance:
                }
 
                /*
-                * Suspend converts GFP_KERNEL to __GFP_WAIT which can
-                * prevent reclaim making forward progress without
-                * invoking OOM. Bail if we are suspending
+                * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent
+                * reclaim making forward progress without invoking OOM.
+                * Suspend also disables storage devices so kswapd cannot save
+                * us.  Bail if we are suspending.
                 */
                if (pm_suspending())
                        goto nopage;