Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754559Ab1D0ICl (ORCPT ); Wed, 27 Apr 2011 04:02:41 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:53519 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753500Ab1D0ICi (ORCPT ); Wed, 27 Apr 2011 04:02:38 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Wed, 27 Apr 2011 16:55:58 +0900 From: KAMEZAWA Hiroyuki To: Minchan Kim Cc: Andrew Morton , linux-mm , LKML , Christoph Lameter , Johannes Weiner , KOSAKI Motohiro , Mel Gorman , Rik van Riel , Andrea Arcangeli Subject: Re: [RFC 2/8] compaction: make isolate_lru_page with filter aware Message-Id: <20110427165558.463e6562.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <4dc5e63cfc8672426336e43dea29057d5bb6e863.1303833417.git.minchan.kim@gmail.com> References: <4dc5e63cfc8672426336e43dea29057d5bb6e863.1303833417.git.minchan.kim@gmail.com> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 3.1.0 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1144 Lines: 28 On Wed, 27 Apr 2011 01:25:19 +0900 Minchan Kim wrote: > In async mode, compaction doesn't migrate dirty or writeback pages. > So, it's meaningless to pick the page and re-add it to lru list. > > Of course, when we isolate the page in compaction, the page might > be dirty or writeback but when we try to migrate the page, the page > would be not dirty, writeback. So it could be migrated. But it's > very unlikely as isolate and migration cycle is much faster than > writeout. > > So, this patch helps cpu and prevent unnecessary LRU churning. > > Cc: KOSAKI Motohiro > Cc: Mel Gorman > Cc: Rik van Riel > Cc: Andrea Arcangeli > Signed-off-by: Minchan Kim seems very nice to me. Thank you. Reviewed-by: KAMEZAWA Hiroyuki -- 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/