[Devel] Re: [PATCH v2 07/11] mm: Allocate kernel pages to the right memcg

[Glauber Costa]

On 08/10/2012 09:33 PM, Kamezawa Hiroyuki wrote:
> (2012/08/09 22:01), Glauber Costa wrote:
>> When a process tries to allocate a page with the __GFP_KMEMCG flag, the
>> page allocator will call the corresponding memcg functions to validate
>> the allocation. Tasks in the root memcg can always proceed.
>>
>> To avoid adding markers to the page - and a kmem flag that would
>> necessarily follow, as much as doing page_cgroup lookups for no reason,
>> whoever is marking its allocations with __GFP_KMEMCG flag is responsible
>> for telling the page allocator that this is such an allocation at
>> free_pages() time. This is done by the invocation of
>> __free_accounted_pages() and free_accounted_pages().
>>
>> Signed-off-by: Glauber Costa <glommer at parallels.com>
>> CC: Christoph Lameter <cl at linux.com>
>> CC: Pekka Enberg <penberg at cs.helsinki.fi>
>> CC: Michal Hocko <mhocko at suse.cz>
>> CC: Kamezawa Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
>> CC: Johannes Weiner <hannes at cmpxchg.org>
>> CC: Suleiman Souhlal <suleiman at google.com>
> 
> Ah, ok. free_accounted_page() seems good.
> 
> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
> 
> I myself is okay with this. But...
> 
> Because you add a new hook to alloc_pages(), please get Ack from Mel
> before requesting merge.
> 
> Thanks,
> -Kame

Absolutely.

Mel, would you mind taking a look at this series and commenting on this?

Thanks in advance.