Re: [PATCH tip:x86/mm 1/3] x86: A fast way to check capabilitiesof the current cpu

From: H. Peter Anvin
Date: Wed Mar 30 2011 - 12:00:17 EST


On 03/14/2011 12:49 PM, Andi Kleen wrote:
> Tejun Heo <tj@xxxxxxxxxx> writes:
>
>> Add this_cpu_has() which determines if the current cpu has a certain
>> ability using a segment prefix and a bit test operation.
>
>
> Hmm: if the CPU capability is really tested in a performance critical
> path, wouldn't it even be better to just use static_branch() now?
>

We have static_cpu_has() for this specific purpose (it actually predates
static_branch()).

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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