Re: Memory usage with qemu-kvm-0.12.1.1

[Rik van Riel <riel@redhat.com>]

On 12/27/2009 11:03 AM, Avi Kivity wrote:
> On 12/27/2009 05:51 PM, Daniel Bareiro wrote:
>> Hi, all!
>>
>> I installed qemu-kvm-0.12.1.1 in one equipment of my house yesterday to
>> test it with Linux 2.6.32 compiled by myself from the source code of
>> kernel.org.
>>
>> From the night of yesterday that I am observing a high use of swap. This
>> is the Service Log Entries from Nagios:
>>
>> 12-26-2009 21:57:33 12-26-2009 23:42:33 0d 1h 45m 0s SERVICE WARNING
>> (HARD) SWAP WARNING - 30% free (142 MB out of 486 MB)
>> 12-26-2009 23:42:33 12-27-2009 00:00:00 0d 0h 17m 27s SERVICE CRITICAL
>> (HARD) SWAP CRITICAL - 9% free (41 MB out of 486 MB)
>> 12-27-2009 00:00:00 12-27-2009 06:27:33 0d 6h 27m 33s SERVICE CRITICAL
>> (HARD) SWAP CRITICAL - 5% free (22 MB out of 486 MB)
>> 12-27-2009 06:27:33 12-27-2009 12:49:51 0d 6h 22m 18s+ SERVICE WARNING
>> (HARD) SWAP WARNING - 14% free (67 MB out of 486 MB)
>>
>> The hour has been ART (GMT-3).
>>
>> The VMs running in this host are the following:
>>
>> +--------------------+----------+------------------+
>> | OS | RAM | SWAP |
>> +====================+==========+==================+
>> | Debian Lenny amd64 | 512 MB | 1 GB / 0 used |
>> | Debian Lenny amd64 | 512 MB | 512 MB / 0 used |
>> | Debian Lenny amd64 | 512 MB | 1 GB / 584k used |
>> | Debian Lenny i386 | 512 MB | 512 MB / 0 used |
>> | OpenBSD 4.6 i386 | 512 MB | 1 GB / 0 used |
>> +--------------------+----------+------------------+
>>
>> This is what I obtain with 'free' in the host:
>>
>> root@ubuntu:~# free
>> total used free shared buffers cached
>> Mem: 4060340 3989512 70828 0 1804272 95212
>> -/+ buffers/cache: 2090028 1970312
>> Swap: 497972 415680 82292
>>
>>
>> To what that so high use of swap can be due?
>>
>
> Probably a regression in Linux swapping. Rik, Hugh, are you aware of
> any? Hugh posted something but it appears to be performance related, not
> causing early swap.

Yes, it is a smal bug in the VM.

A fix has been committed to 2.6.33 already.

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