Re: [PATCH] memcg: implement boost mode

[Kamezawa Hiroyuki <kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>]

(2013/04/01 18:37), Michal Hocko wrote:
> On Mon 01-04-13 13:30:22, Glauber Costa wrote:
>> On 04/01/2013 01:27 PM, Kamezawa Hiroyuki wrote:
>>> (2013/04/01 16:34), Glauber Costa wrote:
>>>> There are scenarios in which we would like our programs to run faster.
>>>> It is a hassle, when they are contained in memcg, that some of its
>>>> allocations will fail and start triggering reclaim. This is not good
>>>> for the program, that will now be slower.
>>>>
>>>> This patch implements boost mode for memcg. It exposes a u64 file
>>>> "memcg boost". Every time you write anything to it, it will reduce the
>>>> counters by ~20 %. Note that we don't want to actually reclaim pages,
>>>> which would defeat the very goal of boost mode. We just make the
>>>> res_counters able to accomodate more.
>>>>
>>>> This file is also available in the root cgroup. But with a slightly
>>>> different effect. Writing to it will make more memory physically
>>>> available so our programs can profit.
>>>>
>>>> Please ack and apply.
>>>>
>>> Nack.
>>>
>>>> Signed-off-by: Glauber Costa <glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
>>>
>>> Please update limit temporary. If you need call-shrink-explicitly-by-user,
>>> I think you can add it.
>>>
>>
>> I don't want to shrink memory because that will make applications
>> slower. I want them to be faster, so they need to have more memory.
>> There is solid research backing up my approach:
>> http://www.dilbert.com/fast/2008-05-08/
>
> :)
>
;)

-Kame