From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755177AbaFBOdt (ORCPT ); Mon, 2 Jun 2014 10:33:49 -0400 Received: from cantor2.suse.de ([195.135.220.15]:47602 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754041AbaFBOds (ORCPT ); Mon, 2 Jun 2014 10:33:48 -0400 Message-ID: <538C8B45.6070803@suse.cz> Date: Mon, 02 Jun 2014 16:33:41 +0200 From: Vlastimil Babka User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Fabio Estevam , Andrew Morton CC: Shawn Guo , Kevin Hilman , Rik van Riel , Stephen Warren , Minchan Kim , Bartlomiej Zolnierkiewicz , Hugh Dickins , LKML , Michal Nazarewicz , linux-mm@kvack.org, Mel Gorman , David Rientjes , Olof Johansson , Greg Thelen , Joonsoo Kim , Christoph Lameter , linux-arm-kernel Subject: [PATCH -mm] mm, compaction: properly signal and act upon lock and need_sched() contention - fix References: <1399904111-23520-1-git-send-email-vbabka@suse.cz> <1400233673-11477-1-git-send-email-vbabka@suse.cz> <537F082F.50501@suse.cz> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org compact_should_abort() returns true instead of false and vice versa due to changes between v1 and v2 of the patch. This makes both async and sync compaction abort with high probability, and has been reported to cause e.g. soft lockups on some ARM boards, or drivers calling dma_alloc_coherent() fail to probe with CMA enabled on different boards. This patch fixes the return value to match comments and callers expecations. Reported-and-tested-by: Kevin Hilman Reported-and-tested-by: Shawn Guo Tested-by: Stephen Warren Signed-off-by: Vlastimil Babka --- mm/compaction.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index a525cd4..5175019 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -237,13 +237,13 @@ static inline bool compact_should_abort(struct compact_control *cc) if (need_resched()) { if (cc->mode == MIGRATE_ASYNC) { cc->contended = true; - return false; + return true; } cond_resched(); } - return true; + return false; } /* Returns true if the page is within a block suitable for migration to */ -- 1.8.4.5