Re: [PATCHSET x86/core/percpu] improve the first percpu chunk allocation

[H. Peter Anvin]

Rusty Russell wrote:
> On Wednesday 25 February 2009 01:07:24 Tejun Heo wrote:
> > it always
> > saves a 2MB TLB entry for all the non-NUMA machines out there.
>
> Note that everyone keeps talking about "a" TLB entry; I wanted to make
> sure (esp. for those of us reading from the sidelines), it's not: it's
> up to num_possible_cpus() TLB entries.  Of course, many paths won't access
> other CPU's data, but it'd be interesting (and pretty easy) to actually
> instrument how rare this is...

Actually it's up to the number of actual CPUs in the system... obviously 
there isn't any data allocated for non-present CPUs.

	-hpa
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