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

Ingo Molnar
2010-03-16T10:50:21Z

* Avi Kivity <avi@redhat.com> wrote:

> On 03/16/2010 12:20 PM, Ingo Molnar wrote:
> >>>>
> >>>>The symbol server's client can certainly access the bits through vmchannel.
> >>>Ok, that would work i suspect.
> >>>
> >>>Would be nice to have the symbol server in tools/perf/ and also make it easy
> >>>to add it to the initrd via a .config switch or so.
> >>>
> >>>That would have basically all of the advantages of being built into the kernel
> >>>(availability, configurability, transparency, hackability), while having all
> >>>the advantages of a user-space approach as well (flexibility, extensibility,
> >>>robustness, ease of maintenance, etc.).
> >>Note, I am not advocating building the vmchannel client into the host
> >>kernel. [...]
> >Neither am i. What i suggested was a user-space binary/executable built in
> >tools/perf and put into the initrd.
>
> I'm confused - initrd seems to be guest-side. I was talking about the host
> side.

host side doesnt need much support - just some client capability in perf
itself. I suspect vmchannels are sufficiently flexible and configuration-free
for such purposes? (i.e. like a filesystem in essence)

Ingo