Re: [PATCH] perf record: add a shortcut for metrics

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Mon, May 27, 2024 at 12:15:19PM +0200, Artem Savkov wrote:
> Add -M/--metrics option to perf-record providing a shortcut to record
> metrics and metricgroups. This option mirrors the one in perf-stat.
> 
> Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
> Signed-off-by: Artem Savkov <asavkov@redhat.com>

Not building for me, I needed to add the rblist.h header and also I
think we need to use metricgroup__rblist_init(&mevents), right?

Testing it now.

- Arnaldo

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 18da3ce380152ad1..5d67b0711c166fae 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -27,6 +27,7 @@
 #include "util/session.h"
 #include "util/tool.h"
 #include "util/symbol.h"
+#include "util/rblist.h"
 #include "util/record.h"
 #include "util/cpumap.h"
 #include "util/thread_map.h"
@@ -4017,6 +4018,7 @@ int cmd_record(int argc, const char **argv)
 	set_nobuild('\0', "off-cpu", "no BUILD_BPF_SKEL=1", true);
 # undef set_nobuild
 #endif
+	metricgroup__rblist_init(&mevents);
 
 	/* Disable eager loading of kernel symbols that adds overhead to perf record. */
 	symbol_conf.lazy_load_kernel_maps = true;

> ---
>  tools/perf/Documentation/perf-record.txt |  7 +++-
>  tools/perf/builtin-record.c              | 43 ++++++++++++++++++++++++
>  2 files changed, 49 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> index 6015fdd08fb63..ebb560d137e62 100644
> --- a/tools/perf/Documentation/perf-record.txt
> +++ b/tools/perf/Documentation/perf-record.txt
> @@ -18,7 +18,6 @@ from it, into perf.data - without displaying anything.
>  
>  This file can then be inspected later on, using 'perf report'.
>  
> -
>  OPTIONS
>  -------
>  <command>...::
> @@ -216,6 +215,12 @@ OPTIONS
>  	  na, by_data, by_addr (for mem_blk)
>  	  hops0, hops1, hops2, hops3 (for mem_hops)
>  
> +-M::
> +--metrics::
> +Record metrics or metricgroups specified in a comma separated list.
> +For a group all metrics from the group are added.
> +See perf list output for the possible metrics and metricgroups.
> +
>  --exclude-perf::
>  	Don't record events issued by perf itself. This option should follow
>  	an event selector (-e) which selects tracepoint event(s). It adds a
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 66a3de8ac6618..5828051ff2736 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -40,6 +40,7 @@
>  #include "util/trigger.h"
>  #include "util/perf-hooks.h"
>  #include "util/cpu-set-sched.h"
> +#include "util/metricgroup.h"
>  #include "util/synthetic-events.h"
>  #include "util/time-utils.h"
>  #include "util/units.h"
> @@ -188,6 +189,7 @@ static volatile int done;
>  static volatile int auxtrace_record__snapshot_started;
>  static DEFINE_TRIGGER(auxtrace_snapshot_trigger);
>  static DEFINE_TRIGGER(switch_output_trigger);
> +static char *metrics;
>  
>  static const char *affinity_tags[PERF_AFFINITY_MAX] = {
>  	"SYS", "NODE", "CPU"
> @@ -200,6 +202,25 @@ static inline pid_t gettid(void)
>  }
>  #endif
>  
> +static int append_metric_groups(const struct option *opt __maybe_unused,
> +			       const char *str,
> +			       int unset __maybe_unused)
> +{
> +	if (metrics) {
> +		char *tmp;
> +
> +		if (asprintf(&tmp, "%s,%s", metrics, str) < 0)
> +			return -ENOMEM;
> +		free(metrics);
> +		metrics = tmp;
> +	} else {
> +		metrics = strdup(str);
> +		if (!metrics)
> +			return -ENOMEM;
> +	}
> +	return 0;
> +}
> +
>  static int record__threads_enabled(struct record *rec)
>  {
>  	return rec->opts.threads_spec;
> @@ -3382,6 +3403,9 @@ static struct option __record_options[] = {
>  		     parse_events_option),
>  	OPT_CALLBACK(0, "filter", &record.evlist, "filter",
>  		     "event filter", parse_filter),
> +	OPT_CALLBACK('M', "metrics", &record.evlist, "metric/metric group list",
> +		     "monitor specified metrics or metric groups (separated by ,)",
> +		     append_metric_groups),
>  	OPT_CALLBACK_NOOPT(0, "exclude-perf", &record.evlist,
>  			   NULL, "don't record events from perf itself",
>  			   exclude_perf),
> @@ -3984,6 +4008,7 @@ int cmd_record(int argc, const char **argv)
>  	int err;
>  	struct record *rec = &record;
>  	char errbuf[BUFSIZ];
> +	struct rblist mevents;
>  
>  	setlocale(LC_ALL, "");
>  
> @@ -4153,6 +4178,23 @@ int cmd_record(int argc, const char **argv)
>  	if (record.opts.overwrite)
>  		record.opts.tail_synthesize = true;
>  
> +	if (metrics) {
> +		const char *pmu = parse_events_option_args.pmu_filter ?: "all";
> +		int ret = metricgroup__parse_groups(rec->evlist, pmu, metrics,
> +						false, /* metric_no_group */
> +						false, /* metric_no_merge */
> +						false, /* metric_no_threshold */
> +						rec->opts.target.cpu_list,
> +						rec->opts.target.system_wide,
> +						false, /* hardware_aware_grouping */
> +						&mevents);
> +		if (ret) {
> +			err = ret;
> +			goto out;
> +		}
> +		zfree(&metrics);
> +	}
> +
>  	if (rec->evlist->core.nr_entries == 0) {
>  		bool can_profile_kernel = perf_event_paranoid_check(1);
>  
> @@ -4264,6 +4306,7 @@ int cmd_record(int argc, const char **argv)
>  out_opts:
>  	record__free_thread_masks(rec, rec->nr_threads);
>  	rec->nr_threads = 0;
> +	metricgroup__rblist_exit(&mevents);
>  	evlist__close_control(rec->opts.ctl_fd, rec->opts.ctl_fd_ack, &rec->opts.ctl_fd_close);
>  	return err;
>  }
> -- 
> 2.45.1