From owner-freebsd-hackers@FreeBSD.ORG  Fri Mar 18 15:51:43 2011
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Date: Fri, 18 Mar 2011 17:51:27 +0200
From: Andriy Gapon <avg@freebsd.org>
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To: Kostik Belousov <kostikbel@gmail.com>
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Cc: freebsd-hackers@freebsd.org, Jung-uk Kim <jkim@freebsd.org>,
	Bruce Evans <brde@optusnet.com.au>, Maxim Dounin <mdounin@mdounin.ru>
Subject: Re: get_cyclecount(9) deprecation
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on 18/03/2011 15:56 Kostik Belousov said the following:
> On Fri, Mar 18, 2011 at 05:26:53PM +1100, Bruce Evans wrote:
> ...
>> - set cputicker() has some design bugs.  It assumes that the tick frequency
>>   is the same across all CPUs, but the TSC is per-CPU.  I have an old SMP
>>   system with CPUs of different frequency that can demonstrate bugs from
>>   this.
> We definitely do not support configurations with different models of
> CPUs in SMP, this is what Simmetric is about. Different as in frequency
> or stepping.

Are there any fundamental reasons for us to not support that configuration in
situations where hardware and BIOS (in x86 case) happen to support it?

I am personally more interested in non-uniform topologies like one package having
two cores and another having four.

-- 
Andriy Gapon