Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932283AbcLLF7Y (ORCPT ); Mon, 12 Dec 2016 00:59:24 -0500 Received: from mail-qk0-f196.google.com ([209.85.220.196]:36805 "EHLO mail-qk0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750780AbcLLF7M (ORCPT ); Mon, 12 Dec 2016 00:59:12 -0500 From: Jia He To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Andrew Morton , Vlastimil Babka , Mel Gorman , Michal Hocko , Johannes Weiner , Joonsoo Kim , Taku Izumi , Jia He Subject: [PATCH RFC 1/1] mm, page_alloc: fix incorrect zone_statistics data Date: Mon, 12 Dec 2016 13:59:07 +0800 Message-Id: <1481522347-20393-2-git-send-email-hejianet@gmail.com> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1481522347-20393-1-git-send-email-hejianet@gmail.com> References: <1481522347-20393-1-git-send-email-hejianet@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1028 Lines: 30 In commit b9f00e147f27 ("mm, page_alloc: reduce branches in zone_statistics"), it reconstructed codes to reduce the branch miss rate. Compared with the original logic, it assumed if !(flag & __GFP_OTHER_NODE) z->node would not be equal to preferred_zone->node. That seems to be incorrect. Fixes: commit b9f00e147f27 ("mm, page_alloc: reduce branches in zone_statistics") Signed-off-by: Jia He --- mm/page_alloc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6de9440..474757e 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2568,6 +2568,9 @@ static inline void zone_statistics(struct zone *preferred_zone, struct zone *z, if (z->node == local_nid) { __inc_zone_state(z, NUMA_HIT); __inc_zone_state(z, local_stat); + } else if (z->node == preferred_zone->node) { + __inc_zone_state(z, NUMA_HIT); + __inc_zone_state(z, NUMA_OTHER); } else { __inc_zone_state(z, NUMA_MISS); __inc_zone_state(preferred_zone, NUMA_FOREIGN); -- 2.5.5