Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751591Ab1B1Ftb (ORCPT ); Mon, 28 Feb 2011 00:49:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44420 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751109Ab1B1Fta (ORCPT ); Mon, 28 Feb 2011 00:49:30 -0500 Date: Mon, 28 Feb 2011 06:48:18 +0100 From: Andrea Arcangeli To: KAMEZAWA Hiroyuki 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: <20110228054818.GF22700@random.random> References: <1298664299-10270-1-git-send-email-mel@csn.ul.ie> <1298664299-10270-3-git-send-email-mel@csn.ul.ie> <20110228111746.34f3f3e0.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110228111746.34f3f3e0.kamezawa.hiroyu@jp.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 597 Lines: 12 On Mon, Feb 28, 2011 at 11:17:46AM +0900, KAMEZAWA Hiroyuki wrote: > BTW, I forget why we always take zone->lru_lock with IRQ disabled.... To decrease lock contention in SMP to deliver overall better performance (not sure how much it helps though). It was supposed to be hold for a very short time (PAGEVEC_SIZE) to avoid giving irq latency problems. -- 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/