Re: [RFC PATCH v2 2/3] perf parse-events: Add a retirement latency modifier

[Ian Rogers]

On Mon, Apr 29, 2024 at 2:08 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> On Sat, Apr 27, 2024 at 10:36 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
> >
> > Retirement latency is a separate sampled count used on newer Intel
> > CPUs.
>
> Can you please update the "event modifiers" section in the perf list
> documentation too?

Will do, currently the only users are TMA metrics.

> Also I'm curious if we have a doc for the JSON metric format.

Nope, nor a schema. It'd be worth setting it up and say using it in
the jevents.py parser. Perhaps the json format can be the same as the
`perf list -j` json output too.

Thanks,
Ian

> Thanks,
> Namhyung
>
> >
> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> > ---
> >  tools/perf/util/evsel.h        | 1 +
> >  tools/perf/util/parse-events.c | 2 ++
> >  tools/perf/util/parse-events.h | 1 +
> >  tools/perf/util/parse-events.l | 3 ++-
> >  4 files changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
> > index 43f6fd1dcb4d..bd8e84954e34 100644
> > --- a/tools/perf/util/evsel.h
> > +++ b/tools/perf/util/evsel.h
> > @@ -98,6 +98,7 @@ struct evsel {
> >                 bool                    bpf_counter;
> >                 bool                    use_config_name;
> >                 bool                    skippable;
> > +               bool                    retire_lat;
> >                 int                     bpf_fd;
> >                 struct bpf_object       *bpf_obj;
> >                 struct list_head        config_terms;
> > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> > index 0f308b4db2b9..9c2a76ec8c99 100644
> > --- a/tools/perf/util/parse-events.c
> > +++ b/tools/perf/util/parse-events.c
> > @@ -1818,6 +1818,8 @@ static int parse_events__modifier_list(struct parse_events_state *parse_state,
> >                         evsel->weak_group = true;
> >                 if (mod.bpf)
> >                         evsel->bpf_counter = true;
> > +               if (mod.retire_lat)
> > +                       evsel->retire_lat = true;
> >         }
> >         return 0;
> >  }
> > diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
> > index 5695308efab9..eb94d1247dae 100644
> > --- a/tools/perf/util/parse-events.h
> > +++ b/tools/perf/util/parse-events.h
> > @@ -201,6 +201,7 @@ struct parse_events_modifier {
> >         bool hypervisor : 1;    /* 'h' */
> >         bool guest : 1;         /* 'G' */
> >         bool host : 1;          /* 'H' */
> > +       bool retire_lat : 1;    /* 'R' */
> >  };
> >
> >  int parse_events__modifier_event(struct parse_events_state *parse_state, void *loc,
> > diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
> > index 08ea2d845dc3..85015f080240 100644
> > --- a/tools/perf/util/parse-events.l
> > +++ b/tools/perf/util/parse-events.l
> > @@ -209,6 +209,7 @@ static int modifiers(struct parse_events_state *parse_state, yyscan_t scanner)
> >                 CASE('W', weak);
> >                 CASE('e', exclusive);
> >                 CASE('b', bpf);
> > +               CASE('R', retire_lat);
> >                 default:
> >                         return PE_ERROR;
> >                 }
> > @@ -250,7 +251,7 @@ drv_cfg_term        [a-zA-Z0-9_\.]+(=[a-zA-Z0-9_*?\.:]+)?
> >   * If you add a modifier you need to update check_modifier().
> >   * Also, the letters in modifier_event must not be in modifier_bp.
> >   */
> > -modifier_event [ukhpPGHSDIWeb]{1,15}
> > +modifier_event [ukhpPGHSDIWebR]{1,16}
> >  modifier_bp    [rwx]{1,3}
> >  lc_type        (L1-dcache|l1-d|l1d|L1-data|L1-icache|l1-i|l1i|L1-instruction|LLC|L2|dTLB|d-tlb|Data-TLB|iTLB|i-tlb|Instruction-TLB|branch|branches|bpu|btb|bpc|node)
> >  lc_op_result   (load|loads|read|store|stores|write|prefetch|prefetches|speculative-read|speculative-load|refs|Reference|ops|access|misses|miss)
> > --
> > 2.44.0.769.g3c40516874-goog
> >