From patchwork Thu Sep 20 14:04:30 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 185398 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 95EEC2C00A0 for ; Fri, 21 Sep 2012 00:05:16 +1000 (EST) Received: from localhost ([::1]:35941 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TEhNS-0008KS-0f for incoming@patchwork.ozlabs.org; Thu, 20 Sep 2012 10:05:14 -0400 Received: from eggs.gnu.org ([208.118.235.92]:44150) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TEhN3-00084O-Ms for qemu-devel@nongnu.org; Thu, 20 Sep 2012 10:04:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TEhMu-00085w-Hp for qemu-devel@nongnu.org; Thu, 20 Sep 2012 10:04:49 -0400 Received: from cantor2.suse.de ([195.135.220.15]:37101 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TEhMu-00085M-7S for qemu-devel@nongnu.org; Thu, 20 Sep 2012 10:04:40 -0400 Received: from relay1.suse.de (unknown [195.135.220.254]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx2.suse.de (Postfix) with ESMTP id D8B35A398E; Thu, 20 Sep 2012 16:04:38 +0200 (CEST) From: Mel Gorman To: Richard Davies , Shaohua Li Date: Thu, 20 Sep 2012 15:04:30 +0100 Message-Id: <1348149875-29678-2-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.7.9.2 In-Reply-To: <1348149875-29678-1-git-send-email-mgorman@suse.de> References: <1348149875-29678-1-git-send-email-mgorman@suse.de> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4-2.6 X-Received-From: 195.135.220.15 Cc: KVM , LKML , QEMU-devel , Linux-MM , Avi Kivity , Mel Gorman Subject: [Qemu-devel] [PATCH 1/6] mm: compaction: Abort compaction loop if lock is contended or run too long X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Shaohua Li Changelog since V2 o Fix BUG_ON triggered due to pages left on cc.migratepages o Make compact_zone_order() require non-NULL arg `contended' Changelog since V1 o only abort the compaction if lock is contended or run too long o Rearranged the code by Andrea Arcangeli. isolate_migratepages_range() might isolate no pages if for example when zone->lru_lock is contended and running asynchronous compaction. In this case, we should abort compaction, otherwise, compact_zone will run a useless loop and make zone->lru_lock is even contended. [minchan@kernel.org: Putback pages isolated for migration if aborting] [akpm@linux-foundation.org: compact_zone_order requires non-NULL arg contended] Signed-off-by: Andrea Arcangeli Signed-off-by: Shaohua Li Signed-off-by: Mel Gorman Acked-by: Rik van Riel --- mm/compaction.c | 17 ++++++++++++----- mm/internal.h | 2 +- 2 files changed, 13 insertions(+), 6 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index 7fcd3a5..a8de20d 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -70,8 +70,7 @@ static bool compact_checklock_irqsave(spinlock_t *lock, unsigned long *flags, /* async aborts if taking too long or contended */ if (!cc->sync) { - if (cc->contended) - *cc->contended = true; + cc->contended = true; return false; } @@ -634,7 +633,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, /* Perform the isolation */ low_pfn = isolate_migratepages_range(zone, cc, low_pfn, end_pfn); - if (!low_pfn) + if (!low_pfn || cc->contended) return ISOLATE_ABORT; cc->migrate_pfn = low_pfn; @@ -787,6 +786,8 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) switch (isolate_migratepages(zone, cc)) { case ISOLATE_ABORT: ret = COMPACT_PARTIAL; + putback_lru_pages(&cc->migratepages); + cc->nr_migratepages = 0; goto out; case ISOLATE_NONE: continue; @@ -831,6 +832,7 @@ static unsigned long compact_zone_order(struct zone *zone, int order, gfp_t gfp_mask, bool sync, bool *contended) { + unsigned long ret; struct compact_control cc = { .nr_freepages = 0, .nr_migratepages = 0, @@ -838,12 +840,17 @@ static unsigned long compact_zone_order(struct zone *zone, .migratetype = allocflags_to_migratetype(gfp_mask), .zone = zone, .sync = sync, - .contended = contended, }; INIT_LIST_HEAD(&cc.freepages); INIT_LIST_HEAD(&cc.migratepages); - return compact_zone(zone, &cc); + ret = compact_zone(zone, &cc); + + VM_BUG_ON(!list_empty(&cc.freepages)); + VM_BUG_ON(!list_empty(&cc.migratepages)); + + *contended = cc.contended; + return ret; } int sysctl_extfrag_threshold = 500; diff --git a/mm/internal.h b/mm/internal.h index b8c91b3..4bd7c0e 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -130,7 +130,7 @@ struct compact_control { int order; /* order a direct compactor needs */ int migratetype; /* MOVABLE, RECLAIMABLE etc */ struct zone *zone; - bool *contended; /* True if a lock was contended */ + bool contended; /* True if a lock was contended */ }; unsigned long