Re: [PATCH] perf/x86/amd/core: Rename branch-brs event to not break the parser

[Michael Petlan <mpetlan@redhat.com>]

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On Tue, 12 Sep 2023, Ian Rogers wrote:
> On Tue, Sep 12, 2023 at 6:35 AM Michael Petlan <mpetlan@redhat.com> wrote:
> >
> > The problem is described in detail in 146edff3d7ed ("perf test: Parse
> > events workaround for dash/minus"). In short, although perf-list offers
> > "branch-brs" event to be used, when used with "-e" switch, the parser
> > does not accept it and needs to be enclosed to "cpu//", such as:
> >
> > ```
> >   $ perf stat -e branch-brs true
> >   event syntax error: 'branch-brs'
> >                              \___ parser error
> >
> >   $ perf stat -e cpu/branch-brs/ true
> >
> >    Performance counter stats for 'true':
> >
> >               46,179      cpu/branch-brs/
> > ```
> >
> > This is confusing for the users.
> >
> > Rename the event using underscore instead of dash to avoid the problem.
> >
> > Signed-off-by: Michael Petlan <mpetlan@redhat.com>
> 
> I rewrote the event parsing and this was fixed in 70c90e4a6b2f ("perf
> parse-events: Avoid scanning PMUs before parsing"):
> https://lore.kernel.org/r/20230502223851.2234828-19-irogers@google.com
> which was included in the perf tool in Linux 6.5.
> 
> Thanks,
> Ian

OK, great to know, thanks!
Michael

> 
> > ---
> >  arch/x86/events/amd/core.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
> > index abadd5f23425..f4c5d4100035 100644
> > --- a/arch/x86/events/amd/core.c
> > +++ b/arch/x86/events/amd/core.c
> > @@ -1286,21 +1286,21 @@ amd_branches_is_visible(struct kobject *kobj, struct attribute *attr, int i)
> >  }
> >
> >  static struct attribute_group group_caps_amd_branches = {
> >         .name  = "caps",
> >         .attrs = amd_pmu_branches_attrs,
> >         .is_visible = amd_branches_is_visible,
> >  };
> >
> >  #ifdef CONFIG_PERF_EVENTS_AMD_BRS
> >
> > -EVENT_ATTR_STR(branch-brs, amd_branch_brs,
> > +EVENT_ATTR_STR(branch_brs, amd_branch_brs,
> >                "event=" __stringify(AMD_FAM19H_BRS_EVENT)"\n");
> >
> >  static struct attribute *amd_brs_events_attrs[] = {
> >         EVENT_PTR(amd_branch_brs),
> >         NULL,
> >  };
> >
> >  static umode_t
> >  amd_brs_is_visible(struct kobject *kobj, struct attribute *attr, int i)
> >  {
> > --
> > 2.18.4
> >
> 
>