On Fri, Mar 18, 2011 at 05:51:27PM +0200, Andriy Gapon wrote: > 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.
We do not handle CPU errata/quirks individually per-core. I think that we assume that all cores have the same stepping and thus require the same workarounds, if any, as BSP. Also, I think tsc calibration is done only on BSP, but I may be wrong there.
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