[Devel] Re: [PATCH 09/23] kmem slab accounting basic infrastructure

[KAMEZAWA Hiroyuki]

(2012/04/25 23:38), Glauber Costa wrote:

> On 04/24/2012 10:32 PM, KAMEZAWA Hiroyuki wrote:
>> (2012/04/21 6:57), Glauber Costa wrote:
>>
>>> This patch adds the basic infrastructure for the accounting of the slab
>>> caches. To control that, the following files are created:
>>>
>>>   * memory.kmem.usage_in_bytes
>>>   * memory.kmem.limit_in_bytes
>>>   * memory.kmem.failcnt
>>>   * memory.kmem.max_usage_in_bytes
>>>
>>> They have the same meaning of their user memory counterparts. They reflect
>>> the state of the "kmem" res_counter.
>>>
>>> The code is not enabled until a limit is set. This can be tested by the flag
>>> "kmem_accounted". This means that after the patch is applied, no behavioral
>>> changes exists for whoever is still using memcg to control their memory usage.
>>>
>>
>> Hmm, res_counter never goes naeative ?
> 
> Why would it?
> 
> This one has more or less the same logic as the sock buffers.
> 
> If we are not accounted, the caches don't get created. If the caches
> don't get created, we don't release them. (this is modulo bugs, of course)

Okay. Please note how the logic works in description or Doc. 
It's a bit complicated part.

Thanks,
-Kame