From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753593AbYA1GoK (ORCPT ); Mon, 28 Jan 2008 01:44:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750802AbYA1Gn7 (ORCPT ); Mon, 28 Jan 2008 01:43:59 -0500 Received: from an-out-0708.google.com ([209.85.132.250]:40727 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750780AbYA1Gn6 (ORCPT ); Mon, 28 Jan 2008 01:43:58 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=vvmOAjfnk4bFInczxxpMzKJb4Ous2FVxE1uaOZPbpV7uaSWklnpAbA92IH4iyqKvqB8yKc+gn2BDcaZAu9Ny/zo37DV087K8GAnIZlswotx1NcJEkbhEAHnzAOju7ASTTCjoAMUYDXZYaBjcUtpickbyuWxMSPjfHf5yFUOXv9c= Message-ID: <28c262360801272243h71bf4464s431d1377051c756b@mail.gmail.com> Date: Mon, 28 Jan 2008 15:43:56 +0900 From: "minchan kim" To: "Andrew Morton" Subject: Re: [PATCH] remove duplicating priority setting in try_to_free_p Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Martin Bligh" , "Nick Piggin" In-Reply-To: <20080127213312.517b8014.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <28c262360801252329q7232edc2l2d0e4ed17c054832@mail.gmail.com> <20080127213312.517b8014.akpm@linux-foundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Jan 28, 2008 2:33 PM, Andrew Morton wrote: > > On Sat, 26 Jan 2008 02:29:23 -0500 "minchan kim" wrote: > > > shrink_zones in try_to_free_pages already set zone through > > note_zone_scanning_priority. > > So, setting prev_priority in try_to_free_pages is needless. > > > > This patch is made by 2.6.24-rc8. > > > > Signed-off-by: barrios > > --- > > mm/vmscan.c | 17 ----------------- > > 1 files changed, 0 insertions(+), 17 deletions(-) > > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index e5a9597..fc55c23 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -1273,23 +1273,6 @@ unsigned long try_to_free_pages(struct z > > if (!sc.all_unreclaimable) > > ret = 1; > > out: > > - /* > > - * Now that we've scanned all the zones at this priority level, note > > - * that level within the zone so that the next thread which performs > > - * scanning of this zone will immediately start out at this priority > > - * level. This affects only the decision whether or not to bring > > - * mapped pages onto the inactive list. > > - */ > > - if (priority < 0) > > - priority = 0; > > - for (i = 0; zones[i] != NULL; i++) { > > - struct zone *zone = zones[i]; > > - > > - if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) > > - continue; > > - > > - zone->prev_priority = priority; > > - } > > return ret; > > } > > (your mail client is replacing tabs with spaces) Thank for your kindness. > I think this is actually a bugfix. The code you're removing doesn't do the > > if (priority < zone->prev_priority) > > thing. > shrink_zones() in try_to_free_pages() already called note_zone_scanning_priority(). So, it have done it. > otoh with this change, the only thing which will cause prev_priority to > increase (ie: lower priority) is kswapd, which seems odd. > So, There is not only kswapd but also direct page reclaim. > So: > > a) this is a functional change and needs more thought and lots of runtime > testing. I'll duck it for now. > > b) the prev_priority stuff is still screwed up. > -- Kinds regards, barrios