On Fri, 2011-03-04 at 19:27 +0100, Nikola Ciprich wrote: > Hello Zachary, > > > You don't see any messages about TSC being unstable or switching > > clocksource after loading the KVM module? And you are not suspending > > the host or anything? > no messages, no suspending, nothing. > > > > Can you try using "processor.max_cstate=1" on the host as a kernel > > parameter and see if it makes a difference? > I tried it, no change.. > n. Zach, I don't understand 100 % the logic behind all your tsc changes. But kvm-clock-wise, most of the problems we had in the past were related to the difference in resolution between the tsc and the host clocksource (hpet, acpi_pm, etc), which in his case, it is a non-issue. It does seem to me like some compensation logic kicked in, dismantling an otherwise good tsc. He does have nonstop_tsc, which means it can't get any better. One thing I noticed when reading the culprit patch in bisect, is that in vcpu_load(), there were previously a call to kvm_request_guest_time_update(vcpu) that was removed without a counterpart addition. Any idea about why it was done? Nikola, does adding that line back alleviate the problem for you ? -- 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
