Messages in this thread | | | Date | Wed, 9 Jun 2010 12:27:43 +0200 | From | Ingo Molnar <> | Subject | Re: [RFC] para virt interface of perf to support kvm guest os statistics collection in guest os |
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* Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, 2010-06-09 at 12:41 +0300, Avi Kivity wrote: > > > > >> Disabling the watchdog is unfortunate. Why is it necessary? > > >> > > > perf always uses NMI, so we disable the nmi_watchdog when a perf_event is > > > set up in case they might have impact. > > > > > > > Ok. Is that the case for the hardware pmus as well? If so it might be > > done in common code. > > The x86 hardware pmu implementation disables the lapic watchdog too, but > recent kernels come with a watchdog implementation on top of perf, the old > lapic one will be depricated.
Note, that code is in -tip, queued for v2.6.36.
Ingo
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