From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755091Ab0KIK1o (ORCPT ); Tue, 9 Nov 2010 05:27:44 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:47389 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754252Ab0KIK1m (ORCPT ); Tue, 9 Nov 2010 05:27:42 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Andrea Arcangeli Subject: Re: [PATCH 61 of 66] use compaction for GFP_ATOMIC order > 0 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: References: Message-Id: <20101109151440.BC75.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 19:27:37 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > From: Andrea Arcangeli > > This takes advantage of memory compaction to properly generate pages of order > > 0 if regular page reclaim fails and priority level becomes more severe and we > don't reach the proper watermarks. > > Signed-off-by: Andrea Arcangeli First, I don't think this patch is related to GFP_ATOMIC. So, I think the patch title is a bit misleading. Second, this patch has two changes. 1) remove PAGE_ALLOC_COSTLY_ORDER threshold 2) implement background compaction. please separate them. Third, This patch makes a lot of PFN order page scan and churn LRU aggressively. I'm not sure this aggressive lru shuffling is safe and works effective. I hope you provide some demonstration and/or show benchmark result. Thanks. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id 24FA66B00A0 for ; Tue, 9 Nov 2010 05:27:42 -0500 (EST) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id oA9ARd22022953 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Tue, 9 Nov 2010 19:27:39 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 8AF7845DE51 for ; Tue, 9 Nov 2010 19:27:39 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (s6.gw.fujitsu.co.jp [10.0.50.96]) by m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 6DAC645DE4E for ; Tue, 9 Nov 2010 19:27:39 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 4EF9F1DB8019 for ; Tue, 9 Nov 2010 19:27:39 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 03EAA1DB8015 for ; Tue, 9 Nov 2010 19:27:39 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 61 of 66] use compaction for GFP_ATOMIC order > 0 In-Reply-To: References: Message-Id: <20101109151440.BC75.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Tue, 9 Nov 2010 19:27:37 +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 > > This takes advantage of memory compaction to properly generate pages of order > > 0 if regular page reclaim fails and priority level becomes more severe and we > don't reach the proper watermarks. > > Signed-off-by: Andrea Arcangeli First, I don't think this patch is related to GFP_ATOMIC. So, I think the patch title is a bit misleading. Second, this patch has two changes. 1) remove PAGE_ALLOC_COSTLY_ORDER threshold 2) implement background compaction. please separate them. Third, This patch makes a lot of PFN order page scan and churn LRU aggressively. I'm not sure this aggressive lru shuffling is safe and works effective. I hope you provide some demonstration and/or show benchmark result. Thanks. -- 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/ . 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