mm: fix testorder interaction between two kswapd patches

Adjusting cc715d99e529 "mm: vmscan: forcibly scan highmem if there are
too many buffer_heads pinning highmem" for -stable reveals that it was
slightly wrong once on top of fe2c2a106663 "vmscan: reclaim at order 0
when compaction is enabled", which specifically adds testorder for the
zone_watermark_ok_safe() test.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 49f15ef..7658fd6 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2817,7 +2817,7 @@ loop_again:
                                testorder = 0;
 
                        if ((buffer_heads_over_limit && is_highmem_idx(i)) ||
-                                   !zone_watermark_ok_safe(zone, order,
+                                   !zone_watermark_ok_safe(zone, testorder,
                                        high_wmark_pages(zone) + balance_gap,
                                        end_zone, 0)) {
                                shrink_zone(priority, zone, &sc);