Re: [RFC Patch V1 07/30] mm: Use cpu_to_mem()/numa_mem_id() to support memoryless node

[Tejun Heo]

On Fri, Jul 11, 2014 at 10:55:59AM -0500, Christoph Lameter wrote:
> > Where X is the memless node.  num_mem_id() on X would return either B
> > or C, right?  If B or C can't satisfy the allocation, the allocator
> > would fallback to A from B and D for C, both of which aren't optimal.
> > It should first fall back to C or B respectively, which the allocator
> > can't do anymoe because the information is lost when the caller side
> > performs numa_mem_id().
> 
> True but the advantage is that the numa_mem_id() allows the use of a
> consitent sort of "local" node which increases allocator performance due
> to the abillity to cache objects from that node.

But the allocator can do the mapping the same.  I really don't see why
we'd push the distinction to the individual users.

Thanks.

-- 
tejun
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