RE: [PATCH V8 3/7] perf, record: introduce --freq-perf option

[Liang, Kan]

> 
> On Thu, Sep 03, 2015 at 08:30:59AM -0400, kan.liang@xxxxxxxxx wrote:
> > From: Kan Liang <kan.liang@xxxxxxxxx>
> >
> > To generate the frequency and performance output, perf must sample
> > read special events like cycles, ref-cycles, msr/tsc/, msr/aperf/ or
> > msr/mperf/.
> > With the --freq-perf option, perf record can automatically check and
> > add those event into evlist for sampling read.
> 
> hum, not sure this is a big or small thing:
> 
> [jolsa@ibm-x3650m4-01 perf]$ ./perf record --freq-perf -e cache-misses ls
> 
> SNIP
> 
> [ perf record: Woken up 13 times to write data ] [ perf record: Captured
> and wrote 0.014 MB perf.data (147 samples) ]
> [jolsa@ibm-x3650m4-01 perf]$ ./perf report -D non matching
> read_format[jolsa@ibm-x3650m4-01 perf]$
> 
> 

The issue is not caused by this patch. It's also an issue in current codes.

In perf_session__open, it will check sample_type, sample_id and
read_format for each event by comparing it with the first event.
If the first events group are sample read and the next event is normal
event, it must error out.

I think it's not a bug. Because we should not allow to record events
with different format.

Thanks,
Kan


> jirka
> 
> >
> > Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
> > ---
> >  tools/perf/Documentation/perf-record.txt |  4 ++++
> >  tools/perf/builtin-record.c              | 39
> +++++++++++++++++++++++++++++++-
> >  tools/perf/util/session.h                | 10 ++++++++
> >  3 files changed, 52 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/Documentation/perf-record.txt
> > b/tools/perf/Documentation/perf-record.txt
> > index 2e9ce77..3f40712 100644
> > --- a/tools/perf/Documentation/perf-record.txt
> > +++ b/tools/perf/Documentation/perf-record.txt
> > @@ -308,6 +308,10 @@ This option sets the time out limit. The default
> value is 500 ms.
> >  Record context switch events i.e. events of type PERF_RECORD_SWITCH
> > or  PERF_RECORD_SWITCH_CPU_WIDE.
> >
> > +--freq-perf::
> > +Add frequency and performance related events to do sample read.
> > +These events include cycles, ref-cycles, msr/tsc/, msr/aperf/ and
> msr/mperf/.
> > +
> >  SEE ALSO
> >  --------
> >  linkperf:perf-stat[1], linkperf:perf-list[1] diff --git
> > a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index
> > 142eeb3..e87dda3 100644
> > --- a/tools/perf/builtin-record.c
> > +++ b/tools/perf/builtin-record.c
> > @@ -13,7 +13,7 @@
> >  #include "util/util.h"
> >  #include "util/parse-options.h"
> >  #include "util/parse-events.h"
> > -
> > +#include "util/pmu.h"
> >  #include "util/callchain.h"
> >  #include "util/cgroup.h"
> >  #include "util/header.h"
> > @@ -50,6 +50,7 @@ struct record {
> >  	bool			no_buildid;
> >  	bool			no_buildid_cache;
> >  	long			samples;
> > +	bool			freq_perf;
> >  };
> >
> >  static int record__write(struct record *rec, void *bf, size_t size)
> > @@ -948,6 +949,35 @@ out_free:
> >  	return ret;
> >  }
> >
> > +const char *freq_perf_events[FREQ_PERF_MAX][3] = {
> > +	{ "msr", "tsc", "msr/tsc/" },
> > +	{ "msr", "aperf", "msr/aperf/" },
> > +	{ "msr", "mperf", "msr/mperf/" },
> > +	{ NULL, "cycles", "cycles" },
> > +	{ NULL, "ref-cycles", "ref-cycles" }, };
> > +
> > +static int
> > +record_add_freq_perf_events(struct perf_evlist *evlist) {
> > +	int i;
> > +	char freq_perf_attrs[100];
> > +
> > +	strcpy(freq_perf_attrs, "{cycles,ref-cycles");
> > +	for (i = 0; i < FREQ_PERF_MAX; i++) {
> > +		if ((i == FREQ_PERF_CYCLES) ||
> > +		    (i == FREQ_PERF_REF_CYCLES))
> > +			continue;
> > +		if (pmu_have_event(freq_perf_events[i][0],
> freq_perf_events[i][1])) {
> > +			strcat(freq_perf_attrs, ",");
> > +			strcat(freq_perf_attrs, freq_perf_events[i][2]);
> > +		}
> > +	}
> > +	strcat(freq_perf_attrs, "}:S");
> > +
> > +	return parse_events(evlist, freq_perf_attrs, NULL); }
> > +
> >  static const char * const __record_usage[] = {
> >  	"perf record [<options>] [<command>]",
> >  	"perf record [<options>] -- <command> [<options>]", @@ -1096,6
> > +1126,8 @@ struct option __record_options[] = {
> >  			"per thread proc mmap processing timeout in ms"),
> >  	OPT_BOOLEAN(0, "switch-events",
> &record.opts.record_switch_events,
> >  		    "Record context switch events"),
> > +	OPT_BOOLEAN(0, "freq-perf", &record.freq_perf,
> > +		    "Add frequency and performance related events to do
> sample
> > +read."),
> >  	OPT_END()
> >  };
> >
> > @@ -1157,6 +1189,11 @@ int cmd_record(int argc, const char **argv,
> const char *prefix __maybe_unused)
> >  	if (rec->no_buildid_cache || rec->no_buildid)
> >  		disable_buildid_cache();
> >
> > +	if (rec->freq_perf && record_add_freq_perf_events(rec->evlist))
> {
> > +		pr_err("Cannot set up freq and performance events\n");
> > +		goto out_symbol_exit;
> > +	}
> > +
> >  	if (rec->evlist->nr_entries == 0 &&
> >  	    perf_evlist__add_default(rec->evlist) < 0) {
> >  		pr_err("Not enough memory for event selector list\n");
> diff --git
> > a/tools/perf/util/session.h b/tools/perf/util/session.h index
> > b44afc7..3915be7 100644
> > --- a/tools/perf/util/session.h
> > +++ b/tools/perf/util/session.h
> > @@ -42,6 +42,16 @@ struct perf_session {
> >  #define PRINT_IP_OPT_ONELINE	(1<<4)
> >  #define PRINT_IP_OPT_SRCLINE	(1<<5)
> >
> > +enum perf_freq_perf_index {
> > +	FREQ_PERF_TSC		= 0,
> > +	FREQ_PERF_APERF		= 1,
> > +	FREQ_PERF_MPERF		= 2,
> > +	FREQ_PERF_CYCLES	= 3,
> > +	FREQ_PERF_REF_CYCLES	= 4,
> > +
> > +	FREQ_PERF_MAX
> > +};
> > +
> >  struct perf_tool;
> >
> >  struct perf_session *perf_session__new(struct perf_data_file *file,
> > --
> > 1.8.3.1
> >
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