From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rik van Riel Subject: Re: [PATCH 3/6] mm: compaction: Acquire the zone->lock as late as possible Date: Thu, 20 Sep 2012 14:54:33 -0400 Message-ID: <505B6669.2040104@redhat.com> References: <1348149875-29678-1-git-send-email-mgorman@suse.de> <1348149875-29678-4-git-send-email-mgorman@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Richard Davies , Shaohua Li , Avi Kivity , QEMU-devel , KVM , Linux-MM , LKML To: Mel Gorman Return-path: In-Reply-To: <1348149875-29678-4-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-Id: kvm.vger.kernel.org On 09/20/2012 10:04 AM, Mel Gorman wrote: > Compactions free scanner acquires the zone->lock when checking for PageBuddy > pages and isolating them. It does this even if there are no PageBuddy pages > in the range. > > This patch defers acquiring the zone lock for as long as possible. In the > event there are no free pages in the pageblock then the lock will not be > acquired at all which reduces contention on zone->lock. > > Signed-off-by: Mel Gorman Acked-by: Rik van Riel -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932286Ab2ITS5y (ORCPT ); Thu, 20 Sep 2012 14:57:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:22172 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755357Ab2ITSyl (ORCPT ); Thu, 20 Sep 2012 14:54:41 -0400 Message-ID: <505B6669.2040104@redhat.com> Date: Thu, 20 Sep 2012 14:54:33 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120717 Thunderbird/14.0 MIME-Version: 1.0 To: Mel Gorman CC: Richard Davies , Shaohua Li , Avi Kivity , QEMU-devel , KVM , Linux-MM , LKML Subject: Re: [PATCH 3/6] mm: compaction: Acquire the zone->lock as late as possible References: <1348149875-29678-1-git-send-email-mgorman@suse.de> <1348149875-29678-4-git-send-email-mgorman@suse.de> In-Reply-To: <1348149875-29678-4-git-send-email-mgorman@suse.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/20/2012 10:04 AM, Mel Gorman wrote: > Compactions free scanner acquires the zone->lock when checking for PageBuddy > pages and isolating them. It does this even if there are no PageBuddy pages > in the range. > > This patch defers acquiring the zone lock for as long as possible. In the > event there are no free pages in the pageblock then the lock will not be > acquired at all which reduces contention on zone->lock. > > Signed-off-by: Mel Gorman Acked-by: Rik van Riel From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:58564) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TEltY-0007sl-ET for qemu-devel@nongnu.org; Thu, 20 Sep 2012 14:54:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TEltX-0001bm-G3 for qemu-devel@nongnu.org; Thu, 20 Sep 2012 14:54:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:15530) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TEltX-0001bi-7v for qemu-devel@nongnu.org; Thu, 20 Sep 2012 14:54:39 -0400 Message-ID: <505B6669.2040104@redhat.com> Date: Thu, 20 Sep 2012 14:54:33 -0400 From: Rik van Riel MIME-Version: 1.0 References: <1348149875-29678-1-git-send-email-mgorman@suse.de> <1348149875-29678-4-git-send-email-mgorman@suse.de> In-Reply-To: <1348149875-29678-4-git-send-email-mgorman@suse.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 3/6] mm: compaction: Acquire the zone->lock as late as possible List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mel Gorman Cc: Richard Davies , KVM , QEMU-devel , LKML , Linux-MM , Avi Kivity , Shaohua Li On 09/20/2012 10:04 AM, Mel Gorman wrote: > Compactions free scanner acquires the zone->lock when checking for PageBuddy > pages and isolating them. It does this even if there are no PageBuddy pages > in the range. > > This patch defers acquiring the zone lock for as long as possible. In the > event there are no free pages in the pageblock then the lock will not be > acquired at all which reduces contention on zone->lock. > > Signed-off-by: Mel Gorman Acked-by: Rik van Riel