On 25.08.2013 13:45, Gleb Natapov wrote: > On Fri, Aug 09, 2013 at 09:14:13PM +0200, Stefan Pietsch wrote: >> On 04.08.2013 14:44, Gleb Natapov wrote: >>> On Fri, Aug 02, 2013 at 08:24:38AM +0200, Stefan Pietsch wrote: >>>> On 31.07.2013 11:20, Gleb Natapov wrote: >>>>> On Wed, Jul 31, 2013 at 11:10:01AM +0200, Stefan Pietsch wrote: >>>>>> On 30.07.2013 07:31, Gleb Natapov wrote: >>>>>> >>>>>>> What happen if you run perf on your host (perf record -a)? >>>>>>> Do you see same NMI messages? >>>>>> >>>>>> It seems that "perf record -a" triggers some delayed NMI messages. >>>>>> They appear about 20 or 30 minutes after the command. This seems strange. >>>>> Definitely strange. KVM guest is not running in parallel, correct? 20, 30 >>>>> minutes after perf stopped running or it is running all of the time? >>>> >>>> No, the KVM guest ist not running in parallel. But I'm not able to >>>> clearly reproduce the NMI messages with "perf record". >>>> I start "perf record -a" and after some minutes I stop the recording. >>>> >>>> After that it seems NMI messages appear within a random period of time. >>>> So, I cannot tell what triggers the messages. >>> When you run KVM with coreduo cpu model it emulates PMU which basically >>> make is perf front end. If you can reproduce the messages with perf too >>> it probably means that the problem is not in the KVM itself. If you >>> disabled NMI watchdog in the guest the messages may go away. >>> Can you send your guest's dmesg when you boot it with coreduo mode? >> >> >> The NMI messages appear in the host only. The guest runs as usual. >> >> > I understand that. But enabling guest nmi watchdog is what makes KVM to > use perf subsystem and likely causes this host messages. Try do disable > nmi watchdog in a guest and see what happens. I disabled the watchdog in the guest by booting the kernel with "nmi_watchdog=0". This does not produce any NMI errors. -- 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
