From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756192Ab0AFVh2 (ORCPT ); Wed, 6 Jan 2010 16:37:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932685Ab0AFVh0 (ORCPT ); Wed, 6 Jan 2010 16:37:26 -0500 Received: from one.firstfloor.org ([213.235.205.2]:36640 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755555Ab0AFVh0 (ORCPT ); Wed, 6 Jan 2010 16:37:26 -0500 To: Mel Gorman Cc: Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 4/7] Memory compaction core From: Andi Kleen References: <1262795169-9095-1-git-send-email-mel@csn.ul.ie> <1262795169-9095-5-git-send-email-mel@csn.ul.ie> Date: Wed, 06 Jan 2010 22:37:22 +0100 In-Reply-To: <1262795169-9095-5-git-send-email-mel@csn.ul.ie> (Mel Gorman's message of "Wed, 6 Jan 2010 16:26:06 +0000") Message-ID: <87iqbeykx9.fsf@basil.nowhere.org> User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/22.3 (gnu/linux) 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 Mel Gorman writes: Haven't reviewed the full thing, but one thing I noticed below: > + > + /* > + * Isolate free pages until enough are available to migrate the > + * pages on cc->migratepages. We stop searching if the migrate > + * and free page scanners meet or enough free pages are isolated. > + */ > + spin_lock_irq(&zone->lock); Won't that cause very long lock hold times on large zones? Presumably you need some kind of lock break heuristic. -Andi -- ak@linux.intel.com -- Speaking for myself only. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id 771AA6B0078 for ; Wed, 6 Jan 2010 16:37:27 -0500 (EST) Subject: Re: [PATCH 4/7] Memory compaction core From: Andi Kleen References: <1262795169-9095-1-git-send-email-mel@csn.ul.ie> <1262795169-9095-5-git-send-email-mel@csn.ul.ie> Date: Wed, 06 Jan 2010 22:37:22 +0100 In-Reply-To: <1262795169-9095-5-git-send-email-mel@csn.ul.ie> (Mel Gorman's message of "Wed, 6 Jan 2010 16:26:06 +0000") Message-ID: <87iqbeykx9.fsf@basil.nowhere.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: Mel Gorman writes: Haven't reviewed the full thing, but one thing I noticed below: > + > + /* > + * Isolate free pages until enough are available to migrate the > + * pages on cc->migratepages. We stop searching if the migrate > + * and free page scanners meet or enough free pages are isolated. > + */ > + spin_lock_irq(&zone->lock); Won't that cause very long lock hold times on large zones? Presumably you need some kind of lock break heuristic. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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