The original reporter is seeing this issue on a laptop (as well as the most recent comment), where the cpus do not have the nonstop_tsc flag in /proc/cpuinfo.
This means the TSCs may halt when the cpus enter low-power c-states, and thus are not appropriate for use for system timekeeping. Thus the message and behavior is expeced in this case on this hardware. If the TSC was not disqualified, the reporters would see system hangs and severe time drift. So the kernel is doing the right thing here with respect to the hardware. You can prevent the cpus from entering low-power states by setting processor.max_cstates=1 or idle=poll. This will usually avoid the TSC halting, but will cause the cpu to consume much more power, which isn't usually desired on a laptop. I'd probably close this bug as invalid, since the kernle is working-as- designed (given the hardware constraints). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/975544 Title: Marking TSC unstable due to check_tsc_sync_source failed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/975544/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
