From: Zhang Yanfei <zhangyan...@cn.fujitsu.com>

In __rmqueue_fallback(), current_order loops down from MAX_ORDER - 1
to the order passed. MAX_ORDER is typically 11 and pageblock_order
is typically 9 on x86. Integer division truncates, so pageblock_order / 2
is 4.  For the first eight iterations, it's guaranteed that
current_order >= pageblock_order / 2 if it even gets that far!

So just remove the unlikely(), it's completely bogus.

Suggested-by: David Rientjes <rient...@google.com>
Signed-off-by: Zhang Yanfei <zhangyan...@cn.fujitsu.com>
---
 mm/page_alloc.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c3edb62..7b4f367 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1050,7 +1050,7 @@ __rmqueue_fallback(struct zone *zone, int order, int 
start_migratetype)
                         * MIGRATE_CMA areas.
                         */
                        if (!is_migrate_cma(migratetype) &&
-                           (unlikely(current_order >= pageblock_order / 2) ||
+                           (current_order >= pageblock_order / 2 ||
                             start_migratetype == MIGRATE_RECLAIMABLE ||
                             page_group_by_mobility_disabled)) {
                                int pages;
-- 
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to