vmscan: fix a livelock in kswapd

[deliverable/linux.git] / mm / vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 5ed24b94c5e69a0dbe6c361ccb0665e3fcc591af..d036e59d302b092bc4186dbb753066416e35c9f6 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2310,7 +2310,8 @@ static bool pgdat_balanced(pg_data_t *pgdat, unsigned long balanced_pages,
        for (i = 0; i <= classzone_idx; i++)
                present_pages += pgdat->node_zones[i].present_pages;
 
-       return balanced_pages > (present_pages >> 2);
+       /* A special case here: if zone has no page, we think it's balanced */
+       return balanced_pages >= (present_pages >> 2);
 }
 
 /* is kswapd sleeping prematurely? */