From: "H. Peter Anvin" <hpa@zytor.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: Tejun Heo <tj@kernel.org>, Ingo Molnar <mingo@elte.hu>,
Thomas Gleixner <tglx@linutronix.de>,
x86@kernel.org, Christoph Lameter <cl@linux.com>,
linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Pekka Enberg <penberg@kernel.org>
Subject: Re: [PATCH tip:x86/mm 1/3] x86: A fast way to check capabilities of the current cpu
Date: Wed, 30 Mar 2011 08:58:23 -0700 [thread overview]
Message-ID: <4D93531F.5080403@zytor.com> (raw)
In-Reply-To: <m2k4g1zdmt.fsf@firstfloor.org>
On 03/14/2011 12:49 PM, Andi Kleen wrote:
> Tejun Heo <tj@kernel.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?
>
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.
next prev parent reply other threads:[~2011-03-30 16:00 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-12 11:50 [PATCH tip:x86/mm 1/3] x86: A fast way to check capabilities of the current cpu Tejun Heo
2011-03-12 11:50 ` [PATCH tip:x86/mm 2/3] x86: Use this_cpu_has for thermal_interrupt " Tejun Heo
2011-03-12 11:51 ` [PATCH tip:x86/mm 3/3] acpi throttling: Use this_cpu_has and simplify code " Tejun Heo
2011-03-28 16:40 ` Tejun Heo
2011-03-30 14:20 ` Christoph Lameter
2011-03-30 15:19 ` Tejun Heo
2011-03-14 19:49 ` [PATCH tip:x86/mm 1/3] x86: A fast way to check capabilities of the " Andi Kleen
2011-03-30 15:58 ` H. Peter Anvin [this message]
2011-03-30 16:07 ` Tejun Heo
2011-03-30 16:15 ` Christoph Lameter
2011-03-30 16:16 ` H. Peter Anvin
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