From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx198.postini.com [74.125.245.198]) by kanga.kvack.org (Postfix) with SMTP id CB3DC6B0005 for ; Wed, 10 Apr 2013 01:15:48 -0400 (EDT) Received: by mail-pa0-f54.google.com with SMTP id fa11so106258pad.27 for ; Tue, 09 Apr 2013 22:15:47 -0700 (PDT) Message-ID: <5164F57E.3030106@gmail.com> Date: Wed, 10 Apr 2013 13:15:42 +0800 From: Ric Mason 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> <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: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Simon Jeons , Mel Gorman , Andrew Morton , Hedi Berriche , linux-mm@kvack.org, linux-kernel@vger.kernel.org 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, 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