Messages in this thread | | | Date | Thu, 27 Sep 2012 14:34:35 +0100 | From | Mel Gorman <> | Subject | Re: [PATCH v3 05/13] Add a __GFP_KMEMCG flag |
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On Tue, Sep 18, 2012 at 06:04:02PM +0400, Glauber Costa wrote: > This flag is used to indicate to the callees that this allocation is a > kernel allocation in process context, and should be accounted to > current's memcg. It takes numerical place of the of the recently removed > __GFP_NO_KSWAPD. > > Signed-off-by: Glauber Costa <glommer@parallels.com> > CC: Christoph Lameter <cl@linux.com> > CC: Pekka Enberg <penberg@cs.helsinki.fi> > CC: Michal Hocko <mhocko@suse.cz> > CC: Johannes Weiner <hannes@cmpxchg.org> > CC: Suleiman Souhlal <suleiman@google.com> > CC: Rik van Riel <riel@redhat.com> > CC: Mel Gorman <mel@csn.ul.ie> > Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
I agree with Christophs recommendation that this flag always exist instead of being 0 in the !MEMCG_KMEM case. If __GFP_KMEMCG ever is used in another part of the VM (which would be unexpected but still) then the behaviour might differ too much between MEMCG_KMEM and !MEMCG_KMEM cases. As unlikely as the case is, it's not impossible.
For tracing __GFP_KMEMCG should have an entry in include/trace/events/gfpflags.h
Get rid of the CONFIG_MEMCG_KMEM check and update include/trace/events/gfpflags.h and then feel free to stick my Acked-by on it.
-- Mel Gorman SUSE Labs
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