Re: [PATCH] slob: poor man's NUMA, take 2.

[Paul Mundt <lethal@linux-sh.org>]

On Wed, Jun 13, 2007 at 03:47:42PM -0700, Christoph Lameter wrote:
> On Wed, 13 Jun 2007, Matt Mackall wrote:
> 
> > On Wed, Jun 13, 2007 at 06:21:09PM +0900, Paul Mundt wrote:
> > > Here's an updated copy with the node variants always defined.
> > > 
> > > I've left the nid=-1 case in as the default for the non-node variants, as
> > > this is the approach also used by SLUB. alloc_pages() is special cased
> > > for NUMA, and takes the memory policy under advisement when doing the
> > > allocation, so the page ends up in a reasonable place.
> > > 
> > 
> > > +void *__kmalloc(size_t size, gfp_t gfp)
> > > +{
> > > +	return __kmalloc_node(size, gfp, -1);
> > > +}
> > >  EXPORT_SYMBOL(__kmalloc);
> > 
> > > +void *kmem_cache_alloc(struct kmem_cache *c, gfp_t flags)
> > > +{
> > > +	return kmem_cache_alloc_node(c, flags, -1);
> > > +}
> > >  EXPORT_SYMBOL(kmem_cache_alloc);
> > 
> > Now promote these guys to inlines in slab.h. At which point all the
> > new NUMA code become a no-op on !NUMA.
> 
> The fallback code already exists in kmalloc.h for SLAB/SLUB. You just need 
> to enable the #ifdefs for SLOB.
> 
> Fallback is for kmem_cache_alloc_node to kmem_cache_alloc.

Yes, this is what I had originally. Matt wants to go the other way,
having the _node variants always defined, and having the non-node
variants simply wrap in to them.

Doing that only for SLOB makes slab.h a bit messy. We could presumably
switch to that sort of behaviour across the board, but that would cause a
bit of churn in SLAB, so it's probably something we want to avoid.

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