From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx181.postini.com [74.125.245.181]) by kanga.kvack.org (Postfix) with SMTP id 46BF86B005D for ; Wed, 15 Aug 2012 15:03:01 -0400 (EDT) Message-ID: <502BF1F2.2020406@redhat.com> Date: Wed, 15 Aug 2012 15:01:06 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: Strange VM stats in /proc/zoneinfo References: <201208151105.27411.ptesarik@suse.cz> In-Reply-To: <201208151105.27411.ptesarik@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: Petr Tesarik Cc: linux-mm@kvack.org On 08/15/2012 05:05 AM, Petr Tesarik wrote: > Hi folks, > > while looking at my /proc/zoneinfo, I noticed that the counters are a bit > strange: > > Node 0, zone DMA > pages free 3945 > min 7 > low 8 > high 10 > scanned 0 > spanned 4080 > present 3905 > nr_free_pages 3945 > > OK, you'll probably argue that the rest is hidden in PCP differentials... BUT: > > 1. this machine has only 2 CPUs > 2. stat_threshold = 4 > 3. vm_stat_diff[NR_FREE_PAGES] = 0 on both CPUs > > Is this only me? Or do I misrepresent what these number actually tell? Present should always be equal to or smaller than spanned, as well as equal to or larger than free. Something looks odd... I wonder if the statistic ends up going off at bootmem free time? -- 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