Messages in this thread | | | Date | Wed, 14 Mar 2018 14:12:37 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v4.16-rc4 2/2] x86/vdso: on Intel, VDSO should handle CLOCK_MONOTONIC_RAW |
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On Wed, Mar 14, 2018 at 12:55:20PM +0000, Jason Vas Dias wrote: > > While CPU_CLOCK is TSC based, there is no guarantee it has any > > correlation to CLOCK_MONOTONIC_RAW (even if that is also TSC based). > > > > (although, I think I might have fixed that recently and it might just > > work, but it's very much not guaranteed). > > Yes, I believe the CPU_CLOCK is effectively the converted TSC - > it does appear to correlate well with the new CLOCK_MONOTONIC_RAW > values from the patched VDSO.
It (now) runs at the same rate, but there is no guarantee for this, in fact it didn't for a very long time.
Relying on this is broken.
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