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

From: David Rientjes
Date: Wed Oct 17 2012 - 18:43:18 EST


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@xxxxxxxxxxxxx>
> Acked-by: Michal Hocko <mhocko@xxxxxxx>
> Acked-by: Mel Gorman <mgorman@xxxxxxx>
> Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> CC: Christoph Lameter <cl@xxxxxxxxx>
> CC: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
> CC: Johannes Weiner <hannes@xxxxxxxxxxx>
> CC: Suleiman Souhlal <suleiman@xxxxxxxxxx>
> CC: Tejun Heo <tj@xxxxxxxxxx>

Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
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