| Subject | Re: [PATCH 1/5] Add a global synchronization point for pvclock | From | Peter Zijlstra <> | Date | Mon, 19 Apr 2010 12:46:15 +0200 |
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On Sat, 2010-04-17 at 21:48 +0300, Avi Kivity wrote: > > After this patch is applied, I don't see a single warp in time during 5 days > > of execution, in any of the machines I saw them before. > > > > > > Please define a cpuid bit that makes this optional. When we eventually > enable it in the future, it will allow a wider range of guests to enjoy it.
Right, so on x86 we have:
X86_FEATURE_CONSTANT_TSC, which only states that TSC is frequency independent, not that it doesn't stop in C states and similar fun stuff.
X86_FEATURE_TSC_RELIABLE, which IIRC should indicate the TSC is constant and synced between cores.
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