On Sun, Aug 12, 2012 at 04:40:48PM +0300, Avi Kivity wrote: > On 08/12/2012 04:25 PM, Gleb Natapov wrote: > > >> How expensive is this? We may want a follow-on patch to cache it in a > >> per-cpu variable. > >> > > I have patches ready. I couldn't measure any overhead of the > > rdmsr(MSR_IA32_DEBUGCTLMSR). > > > > Do you mean while running kvm? How about just running it in a loop? > No, I mean running it in a loop. Loop with or without rdmsr(MSR_IA32_DEBUGCTLMSR) takes the same time as measured by rdtsc. -- Gleb. -- 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
