lkml.org 
[lkml]   [2008]   [Sep]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: Re: [RFC] [PATCH 9/9] memcg: percpu page cgroup lookup cache
----- Original Message -----
>On Thursday 11 September 2008 21:24, KAMEZAWA Hiroyuki wrote:
>> Use per-cpu cache for fast access to page_cgroup.
>> This patch is for making fastpath faster.
>>
>> Because page_cgroup is accessed when the page is allocated/freed,
>> we can assume several of continuous page_cgroup will be accessed soon.
>> (If not interleaved on NUMA...but in such case, alloc/free itself is slow.)
>>
>> We cache some set of page_cgroup's base pointer on per-cpu area and
>> use it when we hit.
>>
>> TODO:
>> - memory/cpu hotplug support.
>
>How much does this help?
>
1-2% in unixbench's test (in 0/9) on 2core/1socket x86-64/SMP host.
(cpu is not the newest one.)
This per-cpu covers 32 * 128MB=4GB of area.
Using 256 bytes(32 entry) is over-kill ?

Thanks,
-Kame


\
 
 \ /
  Last update: 2008-09-11 15:01    [W:0.606 / U:0.296 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site