lkml.org 
[lkml]   [2020]   [Aug]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [RFC] libperf: Add support for user space counter access
On Sat, Aug 8, 2020 at 4:22 AM Jiri Olsa <jolsa@redhat.com> wrote:
>
> On Fri, Aug 07, 2020 at 05:05:17PM -0600, Rob Herring wrote:
> > x86 and arm64 can both support direct access of event counters in
> > userspace. The access sequence is less than trivial and currently exists
> > in perf test code (tools/perf/arch/x86/tests/rdpmc.c) with copies in
> > projects such as PAPI and libpfm4.
> >
> > Patches to add arm64 userspace support are pending[1].
> >
> > For this RFC, looking for a yes, seems like a good idea, or no, go away we
> > don't want this in libperf.
>
> hi,
> looks great!
>
> I wanted to add this for very long time.. so yes, we want this ;-)

Thanks for the quick feedback. Would this be better implemented as a
fast path for perf_evsel__read()? If so, how to get the mmap data
which is associated with a evlist rather than a evsel?

Rob

\
 
 \ /
  Last update: 2020-08-10 20:12    [W:0.052 / U:0.192 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site