[Devel] Re: [PATCH v5 07/14] mm: Allocate kernel pages to the right memcg

[David Rientjes]

On Tue, 16 Oct 2012, 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().
> 
> [ v2: inverted test order to avoid a memcg_get leak,
>   free_accounted_pages simplification ]
> [ v4: test for TIF_MEMDIE at newpage_charge ]
> 
> Signed-off-by: Glauber Costa <glommer at parallels.com>
> Acked-by: Michal Hocko <mhocko at suse.cz>
> Acked-by: Mel Gorman <mgorman at suse.de>
> Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>
> CC: Christoph Lameter <cl at linux.com>
> CC: Pekka Enberg <penberg at cs.helsinki.fi>
> CC: Johannes Weiner <hannes at cmpxchg.org>
> CC: Suleiman Souhlal <suleiman at google.com>
> CC: Tejun Heo <tj at kernel.org>

Acked-by: David Rientjes <rientjes at google.com>