Re: [RFC 00/15] x86_64: Optimize percpu accesses

[H. Peter Anvin]

Christoph Lameter wrote:
> H. Peter Anvin wrote:
>
> > I'm much more concerned about wasting an average of 1 MB of memory per CPU.
>
> Well all the memory that is now allocated via allocpercpu()s will be allocated from  that 2MB segment. And cpu_alloc packs variables in a dense way. The current slab allocations try to avoid sharing cachelines which wastes lots of memory for every allocation for each and every processor.

And how much is that, especially on *small* systems?

	-hpa
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