Re: [PATCH 08/97] mm, thp: do not allow thp faults to avoid cpuset restrictions
From: Mel Gorman
Date: Mon Oct 13 2014 - 11:17:38 EST
On Fri, Sep 26, 2014 at 11:53:14AM +0200, Jiri Slaby wrote:
> On 08/28/2014, 08:34 PM, Mel Gorman wrote:
> > From: David Rientjes <rientjes@xxxxxxxxxx>
> >
> > commit b104a35d32025ca740539db2808aa3385d0f30eb upstream.
> >
> > The page allocator relies on __GFP_WAIT to determine if ALLOC_CPUSET
> > should be set in allocflags. ALLOC_CPUSET controls if a page allocation
> > should be restricted only to the set of allowed cpuset mems.
> >
> > Transparent hugepages clears __GFP_WAIT when defrag is disabled to prevent
> > the fault path from using memory compaction or direct reclaim. Thus, it
> > is unfairly able to allocate outside of its cpuset mems restriction as a
> > side-effect.
> >
> > This patch ensures that ALLOC_CPUSET is only cleared when the gfp mask is
> > truly GFP_ATOMIC by verifying it is also not a thp allocation.
>
> Hi, the time has come to apply this series. Thanks a lot for doing that.
>
Thanks for picking them up!
--
Mel Gorman
SUSE Labs
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