From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752684Ab0KIGUl (ORCPT ); Tue, 9 Nov 2010 01:20:41 -0500 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:60923 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752541Ab0KIGUk (ORCPT ); Tue, 9 Nov 2010 01:20:40 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Andrea Arcangeli Subject: Re: [PATCH 55 of 66] select CONFIG_COMPACTION if TRANSPARENT_HUGEPAGE enabled Cc: kosaki.motohiro@jp.fujitsu.com, 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 In-Reply-To: <89a62752012298bb500c.1288798110@v2.random> References: <89a62752012298bb500c.1288798110@v2.random> Message-Id: <20101109151756.BC7B.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Tue, 9 Nov 2010 15:20:33 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > From: Andrea Arcangeli > > With transparent hugepage support we need compaction for the "defrag" sysfs > controls to be effective. > > Signed-off-by: Andrea Arcangeli > --- > > diff --git a/mm/Kconfig b/mm/Kconfig > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -305,6 +305,7 @@ config NOMMU_INITIAL_TRIM_EXCESS > config TRANSPARENT_HUGEPAGE > bool "Transparent Hugepage Support" > depends on X86 && MMU > + select COMPACTION > help > Transparent Hugepages allows the kernel to use huge pages and > huge tlb transparently to the applications whenever possible. I dislike this. THP and compaction are completely orthogonal. I think you are talking only your performance recommendation. I mean I dislike Kconfig 'select' hell and I hope every developers try to avoid it as far as possible. Thanks. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id E0C098D0005 for ; Tue, 9 Nov 2010 01:20:38 -0500 (EST) Received: from m5.gw.fujitsu.co.jp ([10.0.50.75]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id oA96KaoZ008973 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Tue, 9 Nov 2010 15:20:36 +0900 Received: from smail (m5 [127.0.0.1]) by outgoing.m5.gw.fujitsu.co.jp (Postfix) with ESMTP id 15AE145DE55 for ; Tue, 9 Nov 2010 15:20:36 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (s5.gw.fujitsu.co.jp [10.0.50.95]) by m5.gw.fujitsu.co.jp (Postfix) with ESMTP id E64F245DE53 for ; Tue, 9 Nov 2010 15:20:35 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id AF6B11DB8067 for ; Tue, 9 Nov 2010 15:20:35 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 610C81DB805E for ; Tue, 9 Nov 2010 15:20:35 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 55 of 66] select CONFIG_COMPACTION if TRANSPARENT_HUGEPAGE enabled In-Reply-To: <89a62752012298bb500c.1288798110@v2.random> References: <89a62752012298bb500c.1288798110@v2.random> Message-Id: <20101109151756.BC7B.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Tue, 9 Nov 2010 15:20:33 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Andrea Arcangeli Cc: kosaki.motohiro@jp.fujitsu.com, 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: > From: Andrea Arcangeli > > With transparent hugepage support we need compaction for the "defrag" sysfs > controls to be effective. > > Signed-off-by: Andrea Arcangeli > --- > > diff --git a/mm/Kconfig b/mm/Kconfig > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -305,6 +305,7 @@ config NOMMU_INITIAL_TRIM_EXCESS > config TRANSPARENT_HUGEPAGE > bool "Transparent Hugepage Support" > depends on X86 && MMU > + select COMPACTION > help > Transparent Hugepages allows the kernel to use huge pages and > huge tlb transparently to the applications whenever possible. I dislike this. THP and compaction are completely orthogonal. I think you are talking only your performance recommendation. I mean I dislike Kconfig 'select' hell and I hope every developers try to avoid it as far as possible. Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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