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From: Rik van Riel <riel@redhat.com>
To: Petr Tesarik <ptesarik@suse.cz>
Cc: linux-mm@kvack.org
Subject: Re: Strange VM stats in /proc/zoneinfo
Date: Wed, 15 Aug 2012 15:01:06 -0400	[thread overview]
Message-ID: <502BF1F2.2020406@redhat.com> (raw)
In-Reply-To: <201208151105.27411.ptesarik@suse.cz>

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?


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      parent reply	other threads:[~2012-08-15 19:03 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-15  9:05 Strange VM stats in /proc/zoneinfo Petr Tesarik
2012-08-15 11:37 ` Petr Tesarik
2012-08-15 19:01 ` Rik van Riel [this message]

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