On Mon, May 17, 2010 at 09:38:30AM -1000, Zachary Amsden wrote: > On 05/17/2010 05:36 AM, Glauber Costa wrote: > >On Fri, May 14, 2010 at 04:07:43PM -1000, Zachary Amsden wrote: > >>I believe this fixes the root cause of the kvmclock warp. It's > >>quite a plausible phenomenon, and explains why it was so easy to > >>produce. > >> > >You mean this is the case for both SMP and UP, or just UP as we talked > >before? > > It's possible on both SMP and UP, guest and host. It is impossible > on UP host unless special circumstances come into play (one of my > patches created these circumstances). > > >I don't get the role of upscale in your patch. Frequency changes are > >already handled by the cpufreq notifier. > > The only purpose of upscale is to downscale the measurement of delta > used for counting stats if CPU frequency was raised since last > observed. This is because moving to a faster TSC rate means we > might have counted some cycles at the wrong rate while the rate was > in transition. It doesn't much matter, as the delta for which > "overrun" is logged was computed wrong anyway. mind sending the stats part in a separate patch? > > I'll clean up my patches and resend as a series today. > > Zach -- 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
