Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755077Ab0K2H34 (ORCPT ); Mon, 29 Nov 2010 02:29:56 -0500 Received: from mga02.intel.com ([134.134.136.20]:17302 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754873Ab0K2H3z (ORCPT ); Mon, 29 Nov 2010 02:29:55 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.59,275,1288594800"; d="scan'208";a="578488523" Date: Mon, 29 Nov 2010 15:29:51 +0800 From: Wu Fengguang To: Minchan Kim Cc: Andrew Morton , linux-mm , LKML , Ben Gamari , Rik van Riel , KOSAKI Motohiro , Johannes Weiner , Nick Piggin , Mel Gorman Subject: Re: [PATCH v2 2/3] move ClearPageReclaim Message-ID: <20101129072951.GA22803@localhost> References: <7b50614882592047dfd96f6ca2bb2d0baa8f5367.1290956059.git.minchan.kim@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1676 Lines: 44 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? 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. -- 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/