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From: Andi Kleen <ak@muc.de>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>,
	Andrew Morton <akpm@osdl.org>,
	Keir Fraser <Keir.Fraser@cl.cam.ac.uk>,
	Jeremy Fitzhardinge <jeremy@goop.org>,
	Zachary Amsden <zach@vmware.com>, Pratap <pratap@vmware.com>,
	Chris Wright <chrisw@sous-sol.org>,
	lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 6/6] cpuid neatening.
Date: 25 Jul 2006 03:41:51 +0200
Date: Tue, 25 Jul 2006 03:41:51 +0200	[thread overview]
Message-ID: <20060725014151.GB91138@muc.de> (raw)
In-Reply-To: <44C55E8F.2020200@zytor.com>

On Mon, Jul 24, 2006 at 04:58:07PM -0700, H. Peter Anvin wrote:
> Rusty Russell wrote:
> >Roll all the cpuid asm into one __cpuid call.  It's a little neater,
> >and also means only one place to patch for paravirtualization.
> 
> The whole point of those is to avoid the unnecessary write to memory and 
> pick it back up again.  This patch reintroduces that ugliness.

Modern gcc should optimize this when it is inlined. If it didn't
most abstracted C++ code would be quite unhappy.

Also as far as I know there is only a single time critical CPUID
in the code and it ignores all output arguments.

-Andi

  reply	other threads:[~2006-07-25  1:41 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1153526643.13699.18.camel@localhost.localdomain>
2006-07-22  0:05 ` [PATCH 2/6] reboot.c to use struct Xgt_desc_struct Rusty Russell
     [not found] ` <1153526798.13699.23.camel@localhost.localdomain>
2006-07-22  0:13   ` [PATCH 6/6] cpuid neatening Rusty Russell
2006-07-22  4:12     ` David Schwartz
2006-07-24 23:58     ` H. Peter Anvin
2006-07-25  1:41       ` Andi Kleen [this message]
     [not found] <20060722000328.cd9e7e0e.akpm@osdl.org>
2006-07-22 15:22 ` Rusty Russell

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