On 08/10/2012 09:33 PM, Kamezawa Hiroyuki wrote:

(2012/08/09 22:01), Glauber Costa wrote:

quoted

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 <redacted>
CC: Christoph Lameter <redacted>
CC: Pekka Enberg <penberg-bbCR+/B0CizivPeTLB3BmA@public.gmane.org>
CC: Michal Hocko <redacted>
CC: Kamezawa Hiroyuki <redacted>
CC: Johannes Weiner <redacted>
CC: Suleiman Souhlal <redacted>

Ah, ok. free_accounted_page() seems good.

Acked-by: KAMEZAWA Hiroyuki <redacted>

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.