Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751403Ab0K2IQE (ORCPT ); Mon, 29 Nov 2010 03:16:04 -0500 Received: from mail-iw0-f174.google.com ([209.85.214.174]:37949 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751006Ab0K2IQC convert rfc822-to-8bit (ORCPT ); Mon, 29 Nov 2010 03:16:02 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=GmRjfxP2PwTomqTCE9hEQVfIH7Z+lhJMxOMiwJJzmpGeoOzYphN5Veo2iPbfgJNxDb /TbH+BQl7g9muFi0qetgKVSo6izuxz0ochY9xlCVsp2u7D4QwKFiJ6ZIcSXwAX+dDnx3 l/gMh+RjjKQqiT176x9URm0u8+mvnZJP1YjY8= MIME-Version: 1.0 In-Reply-To: <20101129072951.GA22803@localhost> References: <7b50614882592047dfd96f6ca2bb2d0baa8f5367.1290956059.git.minchan.kim@gmail.com> <20101129072951.GA22803@localhost> Date: Mon, 29 Nov 2010 17:16:01 +0900 Message-ID: Subject: Re: [PATCH v2 2/3] move ClearPageReclaim From: Minchan Kim To: Wu Fengguang Cc: Andrew Morton , linux-mm , LKML , Ben Gamari , Rik van Riel , KOSAKI Motohiro , Johannes Weiner , Nick Piggin , Mel Gorman Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2118 Lines: 60 On Mon, Nov 29, 2010 at 4:29 PM, Wu Fengguang wrote: > On Sun, Nov 28, 2010 at 11:02:56PM +0800, Minchan Kim wrote: >> fe3cba17 added ClearPageReclaim into clear_page_dirty_for_io for >> preventing fast reclaiming readahead marker page. >> >> In this series, PG_reclaim is used by invalidated page, too. >> If VM find the page is invalidated and it's dirty, it sets PG_reclaim >> to reclaim asap. Then, when the dirty page will be writeback, >> clear_page_dirty_for_io will clear PG_reclaim unconditionally. >> It disturbs this serie's goal. >> >> I think it's okay to clear PG_readahead when the page is dirty, not >> writeback time. So this patch moves ClearPageReadahead. >> This patch needs Wu's opinion. > > It's a safe change. The possibility and consequence of races are both > small enough. However the patch could be simplified as follows? If all of file systems use it, I don't mind it. Do all of filesystems use it when the page is dirtied? I was not sure it.(It's why I added Cc. :) If it doesn't have a problem, I hope so. Thanks, Wu. > > Thanks, > Fengguang > --- > > --- linux-next.orig/mm/page-writeback.c 2010-11-29 15:14:54.000000000 +0800 > +++ linux-next/mm/page-writeback.c ? ? ?2010-11-29 15:15:02.000000000 +0800 > @@ -1330,6 +1330,7 @@ int set_page_dirty(struct page *page) > ?{ > ? ? ? ?struct address_space *mapping = page_mapping(page); > > + ? ? ? ClearPageReclaim(page); > ? ? ? ?if (likely(mapping)) { > ? ? ? ? ? ? ? ?int (*spd)(struct page *) = mapping->a_ops->set_page_dirty; > ?#ifdef CONFIG_BLOCK > @@ -1387,7 +1388,6 @@ int clear_page_dirty_for_io(struct page > > ? ? ? ?BUG_ON(!PageLocked(page)); > > - ? ? ? ClearPageReclaim(page); > ? ? ? ?if (mapping && mapping_cap_account_dirty(mapping)) { > ? ? ? ? ? ? ? ?/* > ? ? ? ? ? ? ? ? * Yes, Virginia, this is indeed insane. > -- Kind regards, Minchan Kim -- 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/