From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762691AbZFKLcc (ORCPT ); Thu, 11 Jun 2009 07:32:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753376AbZFKLcY (ORCPT ); Thu, 11 Jun 2009 07:32:24 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:45665 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751688AbZFKLcY (ORCPT ); Thu, 11 Jun 2009 07:32:24 -0400 From: KOSAKI Motohiro To: Mel Gorman Subject: Re: [PATCH for mmotm 0/5] introduce swap-backed-file-mapped count and fix vmscan-change-the-number-of-the-unmapped-files-in-zone-reclaim.patch Cc: kosaki.motohiro@jp.fujitsu.com, Wu Fengguang , linux-mm , LKML , Andrew Morton In-Reply-To: <20090611105259.GC7302@csn.ul.ie> References: <20090611194141.6D5C.A69D9226@jp.fujitsu.com> <20090611105259.GC7302@csn.ul.ie> Message-Id: <20090611200321.6D62.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: Thu, 11 Jun 2009 20:32:23 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Thu, Jun 11, 2009 at 07:42:33PM +0900, KOSAKI Motohiro wrote: > > > On Thu, Jun 11, 2009 at 07:25:09PM +0900, KOSAKI Motohiro wrote: > > > > Recently, Wu Fengguang pointed out vmscan-change-the-number-of-the-unmapped-files-in-zone-reclaim.patch > > > > has underflow problem. > > > > > > > > > > Can you drop this aspect of the patchset please? I'm doing a final test > > > on the scan-avoidance heuristic that incorporates this patch and the > > > underflow fix. Ram (the tester of the malloc()-stall) confirms the patch > > > fixes his problem. > > > > OK. > > insted, I'll join to review your patch :) > > > > Thanks. You should have it now. In particular, I'm interested in hearing you > opinion about patch 1 of the series "Fix malloc() stall in zone_reclaim() > and bring behaviour more in line with expectations V3" and if addresses; > > 1. Does patch 1 address the problem that first led you to develop the patch > vmscan-change-the-number-of-the-unmapped-files-in-zone-reclaim.patch? Yes, thanks. my original issue is 1. mem-hog process eat all pages in one node of numa machine. 2. kswapd run and makes many swapcache. it mean increasing NR_FILE_PAGES - NR_FILE_MAPPED. 3. any page allocation invoke zone reclaim, but the zone don't have any file-backed page at all. distro kernel can reproduce easily, but mainline kernel can't so easy. but I think root cause is remain. it is (NR_FILE_PAGES - NR_FILE_MAPPED) calculation. > 2. Do you think patch 1 should merge with and replace > vmscan-change-the-number-of-the-unmapped-files-in-zone-reclaim.patch? In my personal prefer, your patch seems to have very good description and rewrite almost part of mine. Thus replacing is better. Can you please make replacing patch? > > > > This patch series introduce new vmstat of swap-backed-file-mapped and fix above > > > > patch by it. > > > > I don't think the patch above needs to be fixed by another counter. At > least, once the underflow was fixed up, it handled the malloc-stall without > additional counters. If we need to account swap-backed-file-mapped, we need > another failure case that it addresses to be sure we're doing the right thing. ok, I drop this.