Re: [RFC][PATCH 1/2] perf: Add 'perf kmem' tool

Ingo Molnar
2009-11-20T08:31:01Z

* Pekka Enberg <penberg@cs.helsinki.fi> wrote:

> On Fri, Nov 20, 2009 at 10:14 AM, Ingo Molnar <mingo@elte.hu> wrote:
> > Pekka, Eduard and the other slab hackers might have ideas about what
> > other stats they generally like to see to judge the health of a workload
> > (or system).
>
> kmalloc()/kfree() CPU ping-pong call-sites (i.e. alloc and free
> happening on different CPUs) is one interesting metric we haven't
> implemented yet. Valgrind massif tool type of output graph would be
> helpful as well:
>
> http://valgrind.org/docs/manual/ms-manual.html
>
> On Fri, Nov 20, 2009 at 10:14 AM, Ingo Molnar <mingo@elte.hu> wrote:
> > If this iteration looks good to the slab folks then i can apply it as-is
> > and we can do the other changes relative to that. It looks good to me as
> > a first step, and it's functional already.
>
> Yeah, looks OK to me as the first step. Patch 2 looks premature,
> though, looking at the output of "perf kmem" from patch 1.
>
> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>

Great - thanks for the quick ack!

Regarding patch 2 - can we set some definitive benchmark threshold for
that? I.e. a list of must-have features in 'perf kmem' before we can do
it? 100% information and analysis equivalency with kmemtrace-user tool?
Eduard, what do you think?

Ingo