Re: [PATCH 2/6] perf stat: Fix metrics calculation with event qualifiers

From: Arnaldo Carvalho de Melo
Date: Thu Apr 23 2015 - 18:15:53 EST


Em Wed, Apr 08, 2015 at 10:28:33PM +0900, Namhyung Kim escreveu:
> Hi Jiri and Andi,
> On Tue, Apr 07, 2015 at 11:25:15PM +0200, Jiri Olsa wrote:
> > From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> > % perf stat -e cycles:k,cycles:u,instructions:k,instructions:u true
> >
> > Performance counter stats for 'true':
> >
> > 531,718 cycles:k
> > 203,895 cycles:u
> > 338,151 instructions:k # 0.64 insns per cycle
> > 105,961 instructions:u # 0.52 insns per cycle
> >
> > 0.002989739 seconds time elapsed
> >
> > Previously it would misreport the ratios because they were matching
> > the wrong value.
>
> This patch reminds me of following change:


Yeah, useful, but do we have one for the kernel, hypervisor, guest, etc?
Could we instead have a --cpumode u?k?g?H? combo, so that we could filter by
that?

Applying this series, with your Ack, thanks!

- Arnaldo

> >From a8ae843bf7cff7b68dc39b6f088c43669d140d00 Mon Sep 17 00:00:00 2001
> From: Namhyung Kim <namhyung@xxxxxxxxxx>
> Date: Wed, 8 Apr 2015 21:56:12 +0900
> Subject: [RFC] perf stat: Add -U/--user option
>
> The -U/--user option is to control event modifier for all events easily.
> It has same effect as if adding 'u' modifier to every events.
>
> An example follows:
>
> $ perf stat -U true
>
> Performance counter stats for 'true':
>
> 0.722461 task-clock:uH (msec) # 0.520 CPUs utilized
> 0 context-switches:uH # 0.000 K/sec
> 0 cpu-migrations:uH # 0.000 K/sec
> 41 page-faults:uH # 0.057 M/sec
> 145,341 cycles:uH # 0.201 GHz
> 517,317 stalled-cycles-frontend:uH # 355.93% frontend cycles idle
> 497,570 stalled-cycles-backend:uH # 342.35% backend cycles idle
> 98,846 instructions:uH # 0.68 insns per cycle
> # 5.23 stalled cycles per insn
> 19,552 branches:uH # 27.063 M/sec
> <not counted> branch-misses:uH
>
> 0.001389613 seconds time elapsed
>
> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> ---
> tools/perf/Documentation/perf-stat.txt | 5 ++++-
> tools/perf/builtin-stat.c | 11 +++++++++++
> 2 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
> index 04e150d83e7d..54b0734028a6 100644
> --- a/tools/perf/Documentation/perf-stat.txt
> +++ b/tools/perf/Documentation/perf-stat.txt
> @@ -151,9 +151,12 @@ filter out the startup phase of the program, which is often very different.
>
> -T::
> --transaction::
> -
> Print statistics of transactional execution if supported.
>
> +-U::
> +--user::
> +Collect events only in user mode execution
> +
> EXAMPLES
> --------
>
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index fec089f1c364..d191af942cb4 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -141,6 +141,7 @@ static unsigned int interval = 0;
> static unsigned int initial_delay = 0;
> static unsigned int unit_width = 4; /* strlen("unit") */
> static bool forever = false;
> +static bool mod_user = false;
> static struct timespec ref_time;
> static struct cpu_map *aggr_map;
> static int (*aggr_get_id)(struct cpu_map *m, int cpu);
> @@ -1809,6 +1810,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
> "aggregate counts per physical processor core", AGGR_CORE),
> OPT_UINTEGER('D', "delay", &initial_delay,
> "ms to wait before starting measurement after program start"),
> + OPT_BOOLEAN('U', "user", &mod_user, "Count event only in user mode"),
> OPT_END()
> };
> const char * const stat_usage[] = {
> @@ -1913,6 +1915,15 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
> if (add_default_attributes())
> goto out;
>
> + if (mod_user) {
> + struct perf_evsel *evsel;
> +
> + evlist__for_each(evsel_list, evsel) {
> + evsel->attr.exclude_kernel = 1;
> + evsel->attr.exclude_hv = 1;
> + }
> + }
> +
> target__validate(&target);
>
> if (perf_evlist__create_maps(evsel_list, &target) < 0) {
> --
> 2.3.5
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