From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932925Ab2DKS42 (ORCPT ); Wed, 11 Apr 2012 14:56:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:29960 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754775Ab2DKS41 (ORCPT ); Wed, 11 Apr 2012 14:56:27 -0400 Message-ID: <4F85C813.2050206@redhat.com> Date: Wed, 11 Apr 2012 14:06:11 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.1) Gecko/20120216 Thunderbird/10.0.1 MIME-Version: 1.0 To: Mel Gorman CC: Andrew Morton , Konstantin Khlebnikov , Hugh Dickins , Ying Han , Linux-MM , LKML Subject: Re: [PATCH 0/3] Removal of lumpy reclaim V2 References: <1334162298-18942-1-git-send-email-mgorman@suse.de> <4F85BC8E.3020400@redhat.com> <20120411175215.GI3789@suse.de> In-Reply-To: <20120411175215.GI3789@suse.de> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/11/2012 01:52 PM, Mel Gorman wrote: > On Wed, Apr 11, 2012 at 01:17:02PM -0400, Rik van Riel wrote: >> Next step: get rid of __GFP_NO_KSWAPD for THP, first >> in the -mm kernel >> > > Initially the flag was introduced because kswapd reclaimed too > aggressively. One would like to believe that it would be less of a problem > now but we must avoid a situation where the CPU and reclaim cost of kswapd > exceeds the benefit of allocating a THP. Since kswapd and the direct reclaim code now use the same conditionals for calling compaction, the cost ought to be identical. I agree this is something we should shake out in -mm for a while though, before considering a mainline merge. Andrew, would you be willing to take a removal of __GFP_NO_KSWAPD in -mm, and push it to Linus for the 3.6 kernel if no ill effects are seen in -mm and -next?