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Subject: Re: [PATCH] x86: Export tsc related information in sysfs
From: Peter Zijlstra <peterz@infradead.org>
To: "H. Peter Anvin" <hpa@zytor.com>
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Date: Tue, 18 May 2010 18:52:16 +0200
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On Tue, 2010-05-18 at 09:40 -0700, H. Peter Anvin wrote:
> 
> The problem is that you throw the baby (vsyscall) out with the bathwater
> (user rdtsc). 

Well, we could only flip the CR4 bit when we mark the TSC unsuitable for
gtod. That should be plenty good to tag all userspace trying to use it,
since more than half my machines don't use TSC for clocksource.