On Mon, 2010-04-19 at 13:49 +0300, Avi Kivity wrote: > On 04/19/2010 01:46 PM, Peter Zijlstra wrote: > > 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. > > > > > > Sockets and boards too? (IOW, how reliable is TSC_RELIABLE)? Not sure, IIRC we clear that when the TSC sync test fails, eg when we mark the tsc clocksource unusable. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
