On 04/23/2013 03:08 AM, Michael S. Tsirkin wrote:
> On Mon, Apr 22, 2013 at 08:35:36PM -0400, Sasha Levin wrote:
>> Due to MQ support we may allocate a whole bunch of rx queues but
>> never use them. With this patch we'll safe the space used by
>> the receive buffers until they are actually in use:
>>
>> sh-4.2# free -h
>> total used free shared buffers cached
>> Mem: 490M 35M 455M 0B 0B 4.1M
>> -/+ buffers/cache: 31M 459M
>> Swap: 0B 0B 0B
>> sh-4.2# ethtool -L eth0 combined 8
>> sh-4.2# free -h
>> total used free shared buffers cached
>> Mem: 490M 162M 327M 0B 0B 4.1M
>> -/+ buffers/cache: 158M 331M
>> Swap: 0B 0B 0B
>>
>> Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
>
> Overall the idea looks fine to me.
>
> I also ask myself whether we should enable multiqueue capability
> with big buffers. 130M extra memory seems excessive.
> Want to try on the kvmtools version that has mergeable buffers?
> Memory use should be much lower.
It is indeed, with mergable buffers:
sh-4.2# free -h
total used free shared buffers cached
Mem: 490M 18M 471M 0B 0B 4.1M
-/+ buffers/cache: 14M 476M
Swap: 0B 0B 0B
sh-4.2# ethtool -L eth0 combined 8
sh-4.2# free -h
total used free shared buffers cached
Mem: 490M 26M 464M 0B 0B 4.1M
-/+ buffers/cache: 22M 468M
Swap: 0B 0B 0B
(18MB? Nice! :) )
Thanks,
Sasha
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