From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751727AbbCUL6O (ORCPT ); Sat, 21 Mar 2015 07:58:14 -0400 Received: from lgeamrelo02.lge.com ([156.147.1.126]:51066 "EHLO lgeamrelo02.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751287AbbCUL6L (ORCPT ); Sat, 21 Mar 2015 07:58:11 -0400 X-Original-SENDERIP: 165.186.175.39 X-Original-MAILFROM: gioh.kim@lge.com From: Gioh Kim To: akpm@linux-foundation.org, vbabka@suse.cz, rientjes@google.com, iamjoonsoo.kim@lge.com Cc: mgorman@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, gunho.lee@lge.com, Gioh Kim , Gioh Kim Subject: [PATCH] mm/compaction: reset compaction scanner positions Date: Sat, 21 Mar 2015 20:58:26 +0900 Message-Id: <1426939106-30347-1-git-send-email-gioh.kim@lge.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the compaction is activated via /proc/sys/vm/compact_memory it would better scan the whole zone. And some platform, for instance ARM, has the start_pfn of a zone is zero. Therefore the first try to compaction via /proc doesn't work. It needs to force to reset compaction scanner position at first. Signed-off-by: Gioh Kim Acked-by: Vlastimil Babka --- mm/compaction.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/mm/compaction.c b/mm/compaction.c index 8c0d945..ccf48ce 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1587,6 +1587,14 @@ static void __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc) INIT_LIST_HEAD(&cc->freepages); INIT_LIST_HEAD(&cc->migratepages); + /* + * When called via /proc/sys/vm/compact_memory + * this makes sure we compact the whole zone regardless of + * cached scanner positions. + */ + if (cc->order == -1) + __reset_isolation_suitable(zone); + if (cc->order == -1 || !compaction_deferred(zone, cc->order)) compact_zone(zone, cc); -- 1.7.9.5