Re: [RFC] SLAB : NUMA cache_free_alien() very expensive because of virt_to_slab(objp); nodeid = slabp->nodeid;

From: Andi Kleen
Date: Tue Mar 20 2007 - 17:32:44 EST


> > Is it possible virt_to_slab(objp)->nodeid being different from pfn_to_nid(objp) ?
>
> It is possible the page allocator falls back to another node than
> requested. We would need to check that this never occurs.

The only way to ensure that would be to set a strict mempolicy.
But I'm not sure that's a good idea -- after all you don't want
to fail an allocation in this case.

But pfn_to_nid on the object like proposed by Eric should work anyways.
But I'm not sure the tables used for that will be more often cache hot
than the slab.

-Andi
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