Messages in this thread | | | Date | Fri, 29 Feb 2008 22:20:08 +0800 | From | "Zhao Forrest" <> | Subject | Re: Can Linux kernel handle unsynced TSC? |
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On 2/29/08, Peter Zijlstra <peterz@infradead.org> wrote: > > On Fri, 2008-02-29 at 16:55 +0800, Zhao Forrest wrote: > > Sorry for reposting it. > > > > For example, > > 1 rdtsc() is invoked on CPU0 > > 2 process is migrated to CPU1, and rdtsc() is invoked on CPU1 > > 3 if TSC on CPU1 is slower than TSC on CPU0, can kernel guarantee > > that the second rdtsc() doesn't return a value smaller than the one > > returned by the first rdtsc()? > > No, rdtsc() goes directly to the hardware. You need a (preferably cheap) > clock abstraction layer on top if you need this.
Thank you for the clarification. I think gettimeofday() is such kind of clock abstraction layer, am I right?
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