Re: [RFC/PATCHSET 00/14] perf report: Add support to accumulate hist periods (v2)

Ingo Molnar
2013-11-11T12:19:15Z

* David Ahern <dsahern@gmail.com> wrote:

> On 11/6/13, 4:47 AM, Ingo Molnar wrote:
> >I'm not too worried about call-graph 'legacies': it generates such huge
> >perf.data files which is parsed so slowly at the moment that there's very
> >little user base ... Anyone who absolutely needs call-graph profiling uses
> >SysProf which performs well.
>
> Actually, perf with callchains is used quite heavily on my products.
> One of the selling points of perf.

That's nice to hear :)

In what way is call-graph profiling utilized typically?

Is it system-wide, i.e. something like:

perf record -a -g sleep 10

? If yes then that would explain why scalability problems rarely surfaced,
it takes a longer user-space profile to get to the event counts where
scalability started hurting.

Thanks,

Ingo