Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753472Ab1B1XHp (ORCPT ); Mon, 28 Feb 2011 18:07:45 -0500 Received: from mx1.redhat.com ([209.132.183.28]:14922 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752696Ab1B1XHo (ORCPT ); Mon, 28 Feb 2011 18:07:44 -0500 Date: Tue, 1 Mar 2011 00:07:12 +0100 From: Andrea Arcangeli To: Minchan Kim Cc: Mel Gorman , Andrew Morton , Arthur Marsh , Clemens Ladisch , Linux-MM , Linux Kernel Mailing List Subject: Re: [PATCH 2/2] mm: compaction: Minimise the time IRQs are disabled while isolating pages for migration Message-ID: <20110228230712.GR22700@random.random> References: <1298664299-10270-1-git-send-email-mel@csn.ul.ie> <1298664299-10270-3-git-send-email-mel@csn.ul.ie> <20110228230131.GB1896@barrios-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110228230131.GB1896@barrios-desktop> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1211 Lines: 26 On Tue, Mar 01, 2011 at 08:01:31AM +0900, Minchan Kim wrote: > I am not sure it's good if we release the lock whenever lru->lock was contended > unconditionally? There are many kinds of lru_lock operations(add to lru, > del from lru, isolation, reclaim, activation, deactivation and so on). This is mostly to mirror cond_resched_lock (which actually uses spin_needbreak but it's ok to have it also when preempt is off). I doubt it makes a big difference but I tried to mirror cond_resched_lock. > Do we really need to release the lock whenever all such operations were contened? > I think what we need is just spin_is_contended_irqcontext. > Otherwise, please write down the comment for justifying for it. What is spin_is_contended_irqcontext? > This patch is for reducing for irq latency but do we have to check signal > in irq hold time? I think it's good idea to check the signal in case the loop is very long and this is run in direct compaction context. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/