linux-kernel - Re: [PATCH tip:x86/mm 1/3] x86: A fast way to check capabilities of the current cpu

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Message-ID: <m2k4g1zdmt.fsf@firstfloor.org>
Date:	Mon, 14 Mar 2011 12:49:14 -0700
From:	Andi Kleen <andi@...stfloor.org>
To:	Tejun Heo <tj@...nel.org>
Cc:	Ingo Molnar <mingo@...e.hu>, Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
	Christoph Lameter <cl@...ux.com>, linux-kernel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Pekka Enberg <penberg@...nel.org>
Subject: Re: [PATCH tip:x86/mm 1/3] x86: A fast way to check capabilities of the current cpu

Tejun Heo <tj@...nel.org> 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? 

-Andi

-- 
ak@...ux.intel.com -- Speaking for myself only
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