Messages in this thread | | | Subject | Re: [PATCH 07/20] Simplify the check on whether cpusets are a factor or not | From | Pekka Enberg <> | Date | Mon, 23 Feb 2009 11:13:23 +0200 |
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On Mon, 2009-02-23 at 10:07 +0100, Peter Zijlstra wrote: > On Mon, 2009-02-23 at 09:14 +0200, Pekka J Enberg wrote: > > On Sun, 22 Feb 2009, Mel Gorman wrote: > > > The check whether cpuset contraints need to be checked or not is complex > > > and often repeated. This patch makes the check in advance to the comparison > > > is simplier to compute. > > > > > > Signed-off-by: Mel Gorman <mel@csn.ul.ie> > > > > You can do that in a cleaner way by defining ALLOC_CPUSET to be zero when > > CONFIG_CPUSETS is disabled. Something like following untested patch: > > > > Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> > > --- > > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index 5675b30..18b687d 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -1135,7 +1135,12 @@ failed: > > #define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */ > > #define ALLOC_HARDER 0x10 /* try to alloc harder */ > > #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ > > + > > +#ifdef CONFIG_CPUSETS > > #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ > > +#else > > +#define ALLOC_CPUSET 0x00 > > +#endif > > > > Mel's patch however even avoids the code when cpusets are configured but > not actively used (the most common case for distro kernels).
Right. Combining both patches is probably the best solution then as we get rid of the #ifdef in get_page_from_freelist().
Pekka
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