Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755632Ab1D2PPE (ORCPT ); Fri, 29 Apr 2011 11:15:04 -0400 Received: from mail-qw0-f46.google.com ([209.85.216.46]:34551 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754796Ab1D2PPC convert rfc822-to-8bit (ORCPT ); Fri, 29 Apr 2011 11:15:02 -0400 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=iTYIoYrS4UU2ImlvrHiDOgQYmpyyBs301tk3If2is7S7SdlGVO/kswj/mPA7DzLMp6 ZrTy7WbOruVFuc0jH/WIySAyCA8vLXCF/UVgzJCE9BNrDQfHGpYLmc6H3zC/JGnms0yF Khzz3rMKfRHNG42KPs6fMSO/dRu1lLDKten2o= MIME-Version: 1.0 In-Reply-To: <20110428084820.GH12437@cmpxchg.org> References: <4dc5e63cfc8672426336e43dea29057d5bb6e863.1303833417.git.minchan.kim@gmail.com> <20110428084820.GH12437@cmpxchg.org> Date: Sat, 30 Apr 2011 00:15:01 +0900 Message-ID: Subject: Re: [RFC 2/8] compaction: make isolate_lru_page with filter aware From: Minchan Kim To: Johannes Weiner Cc: Andrew Morton , linux-mm , LKML , Christoph Lameter , Johannes Weiner , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Mel Gorman , Rik van Riel , Andrea Arcangeli Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2028 Lines: 60 Hi Hannes, On Thu, Apr 28, 2011 at 5:48 PM, Johannes Weiner wrote: > On Wed, Apr 27, 2011 at 01:25:19AM +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 >> --- >>  mm/compaction.c |    2 +- >>  1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/mm/compaction.c b/mm/compaction.c >> index dea32e3..9f80b5a 100644 >> --- a/mm/compaction.c >> +++ b/mm/compaction.c >> @@ -335,7 +335,7 @@ static unsigned long isolate_migratepages(struct zone *zone, >>               } >> >>               /* Try isolate the page */ >> -             if (__isolate_lru_page(page, ISOLATE_BOTH, 0, 0, 0) != 0) >> +             if (__isolate_lru_page(page, ISOLATE_BOTH, 0, !cc->sync, 0) != 0) >>                       continue; > > With the suggested flags argument from 1/8, this would look like: > >        flags = ISOLATE_BOTH; >        if (!cc->sync) >                flags |= ISOLATE_CLEAN; > > ? Yes. I will change it. > > Anyway, nice change indeed! Thanks! -- 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/