Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752601Ab3DJFPt (ORCPT ); Wed, 10 Apr 2013 01:15:49 -0400 Received: from mail-da0-f44.google.com ([209.85.210.44]:57233 "EHLO mail-da0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751746Ab3DJFPs (ORCPT ); Wed, 10 Apr 2013 01:15:48 -0400 Message-ID: <5164F57E.3030106@gmail.com> Date: Wed, 10 Apr 2013 13:15:42 +0800 From: Ric Mason User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: Michal Hocko CC: Simon Jeons , Mel Gorman , Andrew Morton , Hedi Berriche , linux-mm@kvack.org, linux-kernel@vger.kernel.org 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> <5163E7EA.1040608@gmail.com> <20130409101437.GE29860@dhcp22.suse.cz> In-Reply-To: <20130409101437.GE29860@dhcp22.suse.cz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1294 Lines: 37 Hi Michal, On 04/09/2013 06:14 PM, Michal Hocko wrote: > On Tue 09-04-13 18:05:30, Simon Jeons wrote: > [...] >>> 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? > I am not sure which values you have been watching but you have to > realize that you are reading a _partition_ not a file and those pages > go into buffers rather than the page chache. Interesting. ;-) What's the difference between buffers and page cache? Why buffers don't grow? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/