From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754906AbaEGCXS (ORCPT ); Tue, 6 May 2014 22:23:18 -0400 Received: from mail-pd0-f177.google.com ([209.85.192.177]:53422 "EHLO mail-pd0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754324AbaEGCWy (ORCPT ); Tue, 6 May 2014 22:22:54 -0400 Date: Tue, 6 May 2014 19:22:52 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Andrew Morton cc: Mel Gorman , Rik van Riel , Vlastimil Babka , Joonsoo Kim , Greg Thelen , Hugh Dickins , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [patch v3 6/6] mm, compaction: terminate async compaction when rescheduling In-Reply-To: Message-ID: References: User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Async compaction terminates prematurely when need_resched(), see compact_checklock_irqsave(). This can never trigger, however, if the cond_resched() in isolate_migratepages_range() always takes care of the scheduling. If the cond_resched() actually triggers, then terminate this pageblock scan for async compaction as well. Signed-off-by: David Rientjes --- mm/compaction.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/mm/compaction.c b/mm/compaction.c --- a/mm/compaction.c +++ b/mm/compaction.c @@ -500,8 +500,13 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, return 0; } + if (cond_resched()) { + /* Async terminates prematurely on need_resched() */ + if (cc->mode == MIGRATE_ASYNC) + return 0; + } + /* Time to isolate some pages for migration */ - cond_resched(); for (; low_pfn < end_pfn; low_pfn++) { /* give a chance to irqs before checking need_resched() */ if (locked && !(low_pfn % SWAP_CLUSTER_MAX)) {