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Date: Tue, 17 Dec 2002 11:21:53 -0800
From: "H. Peter Anvin" <hpa@transmeta.com>
Organization: Transmeta Corporation
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To: Linus Torvalds <torvalds@transmeta.com>
CC: Ulrich Drepper <drepper@redhat.com>, Alan Cox <alan@lxorguk.ukuu.org.uk>,
       Matti Aarnio <matti.aarnio@zmailer.org>,
       Hugh Dickins <hugh@veritas.com>, Dave Jones <davej@codemonkey.org.uk>,
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       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Intel P6 vs P7 system call performance
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Linus Torvalds wrote:
> 
> On Tue, 17 Dec 2002, Ulrich Drepper wrote:
> 
>>But this is exactly what I expect to happen.  If you want to implement
>>gettimeofday() at user-level you need to modify the page.
> 
> Note that I really don't think we ever want to do the user-level
> gettimeofday(). The complexity just argues against it, it's better to try
> to make system calls be cheap enough that you really don't care.
> 

Let's see... it works fine on UP and on *most* SMP, and on the ones
where it doesn't work you just fill in a system call into the vsyscall
slot.  It just means that gettimeofday() needs a different vsyscall slot.

	-hpa

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