Re: [PATCH v8 2/2] perf evsel: Find process with busy PMUs for EBUSY

From: Chun-Tse Shao

Date: Mon Sep 14 2026 - 16:36:39 EST


On Sun, Sep 13, 2026 at 6:44 PM Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
>
> On Tue, Jun 09, 2026 at 02:20:43PM -0300, Arnaldo Carvalho de Melo wrote:
> > On Tue, Jun 09, 2026 at 08:58:03AM -0700, Ian Rogers wrote:
> > > On Tue, Jun 2, 2026 at 11:13 AM Chun-Tse Shao <ctshao@xxxxxxxxxx> wrote:
> > > >
> > > > It parses fdinfo with PMU type, comparing with the event which failed to
> > > > open, and report the processes causing EBUSY error.
> > > >
> > > > Testing cycles and intel_pt//
> > > >
> > > > $ ./perf stat -e cycles &
> > > > [1] 55569
> > > > $ ./perf stat -e intel_pt// &
> > > > [2] 55683
> > > > $ ./perf stat -e intel_pt//
> > > > Error:
> > > > The PMU intel_pt counters are busy and in use by another process.
> > > > Possible processes:
> > > > 55683 ./perf stat -e intel_pt//
> > > >
> > > > Only perf with intel_pt was reported.
> > > >
> > > > Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>
> > > > Signed-off-by: Chun-Tse Shao <ctshao@xxxxxxxxxx>
> > > > Assisted-by: Gemini:gemini-3.1-pro-preview
> > >
> > > Arnaldo, as the kernel piece of this landed (thanks Peter!) could we
> > > land the tool part too?
> >
> > Thanks for pointing this out to me, I'll do some housekeeping and
> > process this.
>
> I think this hasn't landed, I tried to find the userland part of v8 but
> didn't manage to, can you please point it to me?
>
> - Arnaldo

Hi Arnaldo,

Thanks for taking care this. The link to lkml for this userland part
is: https://lore.kernel.org/all/20260602181349.3969429-2-ctshao@xxxxxxxxxx/

The kernel part
(https://lore.kernel.org/all/20260602181349.3969429-1-ctshao@xxxxxxxxxx/)
was merged by Peter Zijlstra and I can see a tip-bot replied on it.

-CT