Re: [PATCH 2/2] perf: Userspace software event and ioctl

[Pawel Moll <pawel.moll@arm.com>]

On Mon, 2014-11-03 at 14:48 +0000, Tomeu Vizoso wrote:
> On 29 September 2014 17:53, Pawel Moll <pawel.moll@arm.com> wrote:
> > On Mon, 2014-09-29 at 16:32 +0100, Peter Zijlstra wrote:
> >> Also none of the many words above describe
> >> PERF_SAMPLE_USERSPACE_EVENT(), wth is that about?
> >
> > Hopefully description of the v2 makes better job in this:
> >
> > http://thread.gmane.org/gmane.linux.kernel/1793272/focus=4813
> >
> > where it's already called "UEVENT" and was generated by write().
> >
> > Before you get into this, though, the most important outcomes of both v1
> > and v2 discussions:
> >
> > * Ingo suggested prctl(PR_TRACE_UEVENT, type, size, data, 0) as the way
> > of generating such events (so the tracee doesn't have to know the fd to
> > do ioctl); Frederic seems to have the same on his mind.
> >
> > * Namhyung proposed sticking the userspace-originating events into the
> > buffer as PERF_RECORD_UEVENT rather then PERF_SAMPLE_UEVENT.
> >
> > Working on making both happen now.
> 
> are you still working on this? Would be happy to lend a hand if that
> can speed things up.

By all means! In fact I'm typing commit messages right now and will post
the patches later today. Stay tuned and I'm looking forward to all
suggestions, reviews etc.

Cheers!

Pawel