RE: [RFC PATCH v8 5/7] perf stat: Add retire latency print functions to print out at the very end of print out
From: Wang, Weilin
Date: Thu May 16 2024 - 13:52:35 EST
> -----Original Message-----
> From: Ian Rogers <irogers@xxxxxxxxxx>
> Sent: Thursday, May 16, 2024 9:47 AM
> To: Wang, Weilin <weilin.wang@xxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>; Arnaldo Carvalho de Melo
> <acme@xxxxxxxxxx>; Peter Zijlstra <peterz@xxxxxxxxxxxxx>; Ingo Molnar
> <mingo@xxxxxxxxxx>; Alexander Shishkin
> <alexander.shishkin@xxxxxxxxxxxxxxx>; Jiri Olsa <jolsa@xxxxxxxxxx>; Hunter,
> Adrian <adrian.hunter@xxxxxxxxx>; Kan Liang <kan.liang@xxxxxxxxxxxxxxx>;
> linux-perf-users@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Taylor, Perry
> <perry.taylor@xxxxxxxxx>; Alt, Samantha <samantha.alt@xxxxxxxxx>; Biggers,
> Caleb <caleb.biggers@xxxxxxxxx>
> Subject: Re: [RFC PATCH v8 5/7] perf stat: Add retire latency print functions to
> print out at the very end of print out
>
> On Tue, May 14, 2024 at 10:44 PM <weilin.wang@xxxxxxxxx> wrote:
> >
> > From: Weilin Wang <weilin.wang@xxxxxxxxx>
> >
> > Add print out functions so that users could read retire latency values.
> >
> > Example output:
> >
> > Performance counter stats for 'system wide':
> >
> > 25,717 MEM_INST_RETIRED.SPLIT_STORES # 2.2 %
> tma_split_stores
> > 28,365,080 CPU_CLK_UNHALTED.THREAD
> > 24.00 MEM_INST_RETIRED.SPLIT_STORES:R # 96 4
> >
> > 2.054365083 seconds time elapsed
> >
> > This output of retire latency data is in format:
> > <val> <event-name:R> # <sum> <count>.
> >
> > Signed-off-by: Weilin Wang <weilin.wang@xxxxxxxxx>
> > Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>
>
> My usual complaint that I hate the stat-display spaghetti code. We
> keep putting more spaghetti on the plate and this change does this
> too. In the evsel approach:
> https://lore.kernel.org/lkml/20240428053616.1125891-1-
> irogers@xxxxxxxxxx/
> retirement latency events just update the counts for the event and so
> we don't need to special case tpebs events like this. I'd prefer we
> went that route. My reviewed-by no longer stands.
>
Based on the current stat-display code and the original TPEBS counting
code, I believe the code in this commit and last commit was the best way to
do the metric calculation and printout.
But I totally agree with you that if we could get evsel with retire latency work,
this code is not necessary.
I was thinking to plugin the retire latency value into evsel so that I could delete
this and last commit. Do you think that would be a solution?
Thanks,
Weilin
> Thanks,
> Ian
>
> > ---
> > tools/perf/util/stat-display.c | 69
> ++++++++++++++++++++++++++++++++++
> > 1 file changed, 69 insertions(+)
> >
> > diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c
> > index bfc1d705f437..b9c3978cc99c 100644
> > --- a/tools/perf/util/stat-display.c
> > +++ b/tools/perf/util/stat-display.c
> > @@ -21,6 +21,7 @@
> > #include "iostat.h"
> > #include "pmu.h"
> > #include "pmus.h"
> > +#include "intel-tpebs.h"
> >
> > #define CNTR_NOT_SUPPORTED "<not supported>"
> > #define CNTR_NOT_COUNTED "<not counted>"
> > @@ -34,6 +35,7 @@
> > #define COMM_LEN 16
> > #define PID_LEN 7
> > #define CPUS_LEN 4
> > +#define RETIRE_LEN 8
> >
> > static int aggr_header_lens[] = {
> > [AGGR_CORE] = 18,
> > @@ -426,6 +428,71 @@ static void print_metric_std(struct
> perf_stat_config *config,
> > fprintf(out, " %-*s", METRIC_LEN - n - 1, unit);
> > }
> >
> > +static void print_retire_lat_std(struct perf_stat_config *config,
> > + struct outstate *os)
> > +{
> > + FILE *out = os->fh;
> > + bool newline = os->newline;
> > + struct tpebs_retire_lat *t;
> > + struct list_head *retire_lats = &config->tpebs_results;
> > +
> > + list_for_each_entry(t, retire_lats, nd) {
> > + if (newline)
> > + do_new_line_std(config, os);
> > + fprintf(out, "%'*.2f ", COUNTS_LEN, t->val);
> > + /* For print alignment */
> > + fprintf(out, "%-*s ", config->unit_width, "");
> > + fprintf(out, "%-*s", EVNAME_LEN, t->tpebs_name);
> > + fprintf(out, " # ");
> > + fprintf(out, "%*d %*ld\n", RETIRE_LEN, t->sum,
> > + RETIRE_LEN, t->count);
> > + }
> > +}
> > +
> > +static void print_retire_lat_csv(struct perf_stat_config *config,
> > + struct outstate *os)
> > +{
> > + FILE *out = os->fh;
> > + struct tpebs_retire_lat *t;
> > + struct list_head *retire_lats = &config->tpebs_results;
> > + const char *sep = config->csv_sep;
> > +
> > + list_for_each_entry(t, retire_lats, nd) {
> > + fprintf(out, "%f%s%s%s%s%ld%s%d\n", t->val, sep, sep, t-
> >tpebs_name, sep,
> > + t->count, sep, t->sum);
> > + }
> > +}
> > +
> > +static void print_retire_lat_json(struct perf_stat_config *config,
> > + struct outstate *os)
> > +{
> > + FILE *out = os->fh;
> > + struct tpebs_retire_lat *t;
> > + struct list_head *retire_lats = &config->tpebs_results;
> > +
> > + fprintf(out, "{");
> > + list_for_each_entry(t, retire_lats, nd) {
> > + fprintf(out, "\"retire_latency-value\" : \"%f\", ", t->val);
> > + fprintf(out, "\"name\" : \"%s\"", t->tpebs_name);
> > + fprintf(out, "\"sample-counts\" : \"%ld\"", t->count);
> > + fprintf(out, "\"retire_latency-sum\" : \"%d\"", t->sum);
> > + }
> > + fprintf(out, "}");
> > +}
> > +
> > +static void print_retire_lat(struct perf_stat_config *config,
> > + struct outstate *os)
> > +{
> > + if (!&config->tpebs_results)
> > + return;
> > + if (config->json_output)
> > + print_retire_lat_json(config, os);
> > + else if (config->csv_output)
> > + print_retire_lat_csv(config, os);
> > + else
> > + print_retire_lat_std(config, os);
> > +}
> > +
> > static void new_line_csv(struct perf_stat_config *config, void *ctx)
> > {
> > struct outstate *os = ctx;
> > @@ -1609,6 +1676,8 @@ void evlist__print_counters(struct evlist *evlist,
> struct perf_stat_config *conf
> > break;
> > }
> >
> > + print_retire_lat(config, &os);
> > +
> > print_footer(config);
> >
> > fflush(config->output);
> > --
> > 2.43.0
> >