Re: [PATCH] perf/kvm: Guest Symbol Resolution for powerpc

From: Ravi Bangoria
Date: Fri Jan 22 2016 - 01:06:09 EST

Hi Arnaldo,

On Wednesday 13 January 2016 10:29 PM, Arnaldo Carvalho de Melo wrote:
Em Tue, Dec 29, 2015 at 03:38:40PM +0530, Ravi Bangoria escreveu:
'perf kvm {record|report}' is used to record and report the profiled
performance of any workload on a guest. From the host, we can collect
guest kernel statistics which is useful in finding out any contentions
in guest kernel symbols for a certain workload.
This feature is not available on powerpc because 'perf' relies on the
'cycles' event (a PMU event) to profile the guest. However, for powerpc,
this can't be used from the host because the PMUs are controlled by the
guest rather than the host.
Without entering the realms if the approach is the right one, which I
leave to PowerPC experts, Ingo, PeterZ, etc:

So, in these cases, please break this into a series, where you, for
instance, will add that extra evsel parameter to the functions that will
ultimately use it to extract those event fields, that should be a
separate patch, so that when reviewing the "meat" of your patch we can
quickly see what it does, not having to extract that from leg work.

Two other patches should introduce arch__get_{ip,cpumode}().

- Arnaldo

Thanks for suggestion. I've sent v2 with changes you suggested.

Can you please take a look.