From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755154Ab0KIVcL (ORCPT ); Tue, 9 Nov 2010 16:32:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47078 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754770Ab0KIVcI (ORCPT ); Tue, 9 Nov 2010 16:32:08 -0500 Date: Tue, 9 Nov 2010 22:30:49 +0100 From: Andrea Arcangeli To: KOSAKI Motohiro Cc: linux-mm@kvack.org, Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, Marcelo Tosatti , Adam Litke , Avi Kivity , Hugh Dickins , Rik van Riel , Mel Gorman , Dave Hansen , Benjamin Herrenschmidt , Ingo Molnar , Mike Travis , KAMEZAWA Hiroyuki , Christoph Lameter , Chris Wright , bpicco@redhat.com, Balbir Singh , "Michael S. Tsirkin" , Peter Zijlstra , Johannes Weiner , Daisuke Nishimura , Chris Mason , Borislav Petkov Subject: Re: [PATCH 01 of 66] disable lumpy when compaction is enabled Message-ID: <20101109213049.GC6809@random.random> References: <20101109121318.BC51.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101109121318.BC51.A69D9226@jp.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 09, 2010 at 12:18:49PM +0900, KOSAKI Motohiro wrote: > I'm talking very personal thing now. I'm usually testing both feature. > Then, runtime switching makes my happy :-) > However I don't know what are you and Mel talking and agree about this. > So, If many developer prefer this approach, I don't oppose anymore. Mel seem to still prefer I allow lumpy for hugetlbfs with a __GFP_LUMPY specified only for hugetlbfs. But he measured compaction is more reliable than lumpy at creating hugepages so he seems to be ok with this too. > But, I bet almost all distro choose CONFIG_COMPACTION=y. then, lumpy code > will become nearly dead code. So, I like just kill than dead code. however > it is also only my preference. ;) Killing dead code is my preference too indeed. But then it's fine with me to delete it only later. In short this is least intrusive modification I could make to the VM that wouldn't than hang the system when THP is selected because all pte young bits are ignored for >50% of page reclaim invocations like lumpy requires. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id E3BED6B004A for ; Tue, 9 Nov 2010 16:31:43 -0500 (EST) Date: Tue, 9 Nov 2010 22:30:49 +0100 From: Andrea Arcangeli Subject: Re: [PATCH 01 of 66] disable lumpy when compaction is enabled Message-ID: <20101109213049.GC6809@random.random> References: <20101109121318.BC51.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101109121318.BC51.A69D9226@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: linux-mm@kvack.org, Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, Marcelo Tosatti , Adam Litke , Avi Kivity , Hugh Dickins , Rik van Riel , Mel Gorman , Dave Hansen , Benjamin Herrenschmidt , Ingo Molnar , Mike Travis , KAMEZAWA Hiroyuki , Christoph Lameter , Chris Wright , bpicco@redhat.com, Balbir Singh , "Michael S. Tsirkin" , Peter Zijlstra , Johannes Weiner , Daisuke Nishimura , Chris Mason , Borislav Petkov List-ID: On Tue, Nov 09, 2010 at 12:18:49PM +0900, KOSAKI Motohiro wrote: > I'm talking very personal thing now. I'm usually testing both feature. > Then, runtime switching makes my happy :-) > However I don't know what are you and Mel talking and agree about this. > So, If many developer prefer this approach, I don't oppose anymore. Mel seem to still prefer I allow lumpy for hugetlbfs with a __GFP_LUMPY specified only for hugetlbfs. But he measured compaction is more reliable than lumpy at creating hugepages so he seems to be ok with this too. > But, I bet almost all distro choose CONFIG_COMPACTION=y. then, lumpy code > will become nearly dead code. So, I like just kill than dead code. however > it is also only my preference. ;) Killing dead code is my preference too indeed. But then it's fine with me to delete it only later. In short this is least intrusive modification I could make to the VM that wouldn't than hang the system when THP is selected because all pte young bits are ignored for >50% of page reclaim invocations like lumpy requires. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org