From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx205.postini.com [74.125.245.205]) by kanga.kvack.org (Postfix) with SMTP id 4E9A36B0005 for ; Tue, 9 Apr 2013 06:05:37 -0400 (EDT) Received: by mail-pa0-f45.google.com with SMTP id kl13so3750144pab.32 for ; Tue, 09 Apr 2013 03:05:36 -0700 (PDT) Message-ID: <5163E7EA.1040608@gmail.com> Date: Tue, 09 Apr 2013 18:05:30 +0800 From: Simon Jeons MIME-Version: 1.0 Subject: Re: [PATCH] mm: page_alloc: Avoid marking zones full prematurely after zone_reclaim() References: <20130320181957.GA1878@suse.de> <514A7163.5070700@gmail.com> <20130321081902.GD6094@dhcp22.suse.cz> <515E6FC4.5000202@gmail.com> In-Reply-To: <515E6FC4.5000202@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Mel Gorman , Andrew Morton , Hedi Berriche , linux-mm@kvack.org, linux-kernel@vger.kernel.org Hi Michal, On 04/05/2013 02:31 PM, Simon Jeons wrote: > Hi Michal, > On 03/21/2013 04:19 PM, Michal Hocko wrote: >> On Thu 21-03-13 10:33:07, Simon Jeons wrote: >>> Hi Mel, >>> On 03/21/2013 02:19 AM, Mel Gorman wrote: >>>> The following problem was reported against a distribution kernel when >>>> zone_reclaim was enabled but the same problem applies to the mainline >>>> kernel. The reproduction case was as follows >>>> >>>> 1. Run numactl -m +0 dd if=largefile of=/dev/null >>>> This allocates a large number of clean pages in node 0 >>> I confuse why this need allocate a large number of clean pages? >> It reads from file and puts pages into the page cache. The pages are not >> modified so they are clean. Output file is /dev/null so no pages are >> written. dd doesn't call fadvise(POSIX_FADV_DONTNEED) on the input file >> by default so pages from the file stay in the page cache > > I try this in v3.9-rc5: > dd if=/dev/sda of=/dev/null bs=1MB > 14813+0 records in > 14812+0 records out > 14812000000 bytes (15 GB) copied, 105.988 s, 140 MB/s > > free -m -s 1 > > total used free shared buffers > cached > Mem: 7912 1181 6731 0 663 239 > -/+ buffers/cache: 277 7634 > Swap: 8011 0 8011 > > It seems that almost 15GB copied before I stop dd, but the used pages > which I monitor during dd always around 1200MB. Weird, why? > Sorry for waste your time, but the test result is weird, is it? -- 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/ . Don't email: email@kvack.org