(2012/06/18 21:43), Glauber Costa wrote:
> On 06/18/2012 04:37 PM, Kamezawa Hiroyuki wrote:
>> (2012/06/18 19:28), Glauber Costa wrote:
>>> The current memcg slab cache management fails to present satisfatory hierarchical
>>> behavior in the following scenario:
>>>
>>> -> /cgroups/memory/A/B/C
>>>
>>> * kmem limit set at A
>>> * A and B empty taskwise
>>> * bash in C does find /
>>>
>>> Because kmem_accounted is a boolean that was not set for C, no accounting
>>> would be done. This is, however, not what we expect.
>>>
>>
>> Hmm....do we need this new routines even while we have mem_cgroup_iter() ?
>>
>> Doesn't this work ?
>>
>> struct mem_cgroup {
>> .....
>> bool kmem_accounted_this;
>> atomic_t kmem_accounted;
>> ....
>> }
>>
>> at set limit
>>
>> ....set_limit(memcg) {
>>
>> if (newly accounted) {
>> mem_cgroup_iter() {
>> atomic_inc(&iter->kmem_accounted)
>> }
>> } else {
>> mem_cgroup_iter() {
>> atomic_dec(&iter->kmem_accounted);
>> }
>> }
>>
>>
>> hm ? Then, you can see kmem is accounted or not by atomic_read(&memcg->kmem_accounted);
>>
>
> Accounted by itself / parent is still useful, and I see no reason to use
> an atomic + bool if we can use a pair of bits.
>
> As for the routine, I guess mem_cgroup_iter will work... It does a lot
> more than I need, but for the sake of using what's already in there, I
> can switch to it with no problems.
>
Hmm. please start from reusing existing routines.
If it's not enough, some enhancement for generic cgroup will be welcomed
rather than completely new one only for memcg.
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