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

[Tejun Heo]

Hello,

On Wed, Mar 30, 2011 at 08:58:23AM -0700, H. Peter Anvin wrote:
> >> 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()).

These patches have performance benefits but I don't think it would be
noticeable.  I think it's more of code cleanup.

Thanks.

-- 
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/