Re: [PATCH] Enhance perf to collect KVM guest os statistics from host side

Ingo Molnar
2010-03-17T08:14:10Z

* Frank Ch. Eigler <fche@redhat.com> wrote:

> Hi -
>
> On Tue, Mar 16, 2010 at 06:04:10PM -0500, Anthony Liguori wrote:
> > [...]
> > The only way to really address this is to change the interaction.
> > Instead of running perf externally to qemu, we should support a perf
> > command in the qemu monitor that can then tie directly to the perf
> > tooling. That gives us the best possible user experience.
>
> To what extent could this be solved with less crossing of
> isolation/abstraction layers, if the perfctr facilities were properly
> virtualized? [...]

Note, 'perfctr' is a different out-of-tree Linux kernel project run by someone
else: it offers the /dev/perfctr special-purpose device that allows raw,
unabstracted, low-level access to the PMU.

I suspect the one you wanted to mention here is called 'perf' or 'perf
events'. (and used to be called 'performance counters' or 'perfcounters' until
it got renamed about a year ago)

Thanks,

Ingo