2012-06-06 10:41:46

by Peter Zijlstra

[permalink] [raw]
Subject: Re: [perf] exporting perf_pmu_register?

On Thu, 2012-03-15 at 17:41 -0400, Vince Weaver wrote:
> Would a patch similar to
> https://lkml.org/lkml/2010/8/18/64
> be accepted that exported this?
>
If it comes with a patch that uses the exports, sure.


2012-06-06 14:31:27

by Vince Weaver

[permalink] [raw]
Subject: Re: [perf] exporting perf_pmu_register?

On Wed, 6 Jun 2012, Peter Zijlstra wrote:

> On Thu, 2012-03-15 at 17:41 -0400, Vince Weaver wrote:
> > Would a patch similar to
> > https://lkml.org/lkml/2010/8/18/64
> > be accepted that exported this?
> >
> If it comes with a patch that uses the exports, sure.
>

while I understand the logic behind that from a kernel-developer
perspective, it does make things harder in the real world.

In the end PAPI has implemented RAPL support via reading /dev/cpu/*/msr
because it was easier to convince our sysadmin to give us read-only
permission to /dev/cpu/*/msr than to take our in-production Sandybridge-EP
system and patch it up to export perf_pmu_register so we could work on a
proper driver.

Vince