Commit 142544a9 authored by Jiri Olsa's avatar Jiri Olsa Committed by Arnaldo Carvalho de Melo
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perf tools: Add 'evlist' control command 



Add a new 'evlist' control command to display all the evlist events.
When it is received, perf will scan and print current evlist into perf
record terminal.

The interface string for control file is:

  evlist [-v|-g|-F]

The syntax follows perf evlist command:
  -F  Show just the sample frequency used for each event.
  -v  Show all fields.
  -g  Show event group information.

Example session:

  terminal 1:
    # mkfifo control ack
    # perf record --control=fifo:control,ack -e '{cycles,instructions}'

  terminal 2:
    # echo evlist > control

  terminal 1:
    cycles
    instructions
    dummy:HG

  terminal 2:
    # echo 'evlist -v' > control

  terminal 1:
    cycles: size: 120, { sample_period, sample_freq }: 4000, sample_type:            \
    IP|TID|TIME|ID|CPU|PERIOD, read_format: ID, disabled: 1, inherit: 1, freq: 1,    \
    sample_id_all: 1, exclude_guest: 1
    instructions: size: 120, config: 0x1, { sample_period, sample_freq }: 4000,      \
    sample_type: IP|TID|TIME|ID|CPU|PERIOD, read_format: ID, inherit: 1, freq: 1,    \
    sample_id_all: 1, exclude_guest: 1
    dummy:HG: type: 1, size: 120, config: 0x9, { sample_period, sample_freq }: 4000, \
    sample_type: IP|TID|TIME|ID|CPU|PERIOD, read_format: ID, inherit: 1, mmap: 1,    \
    comm: 1, freq: 1, task: 1, sample_id_all: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, \
     bpf_event: 1

  terminal 2:
    # echo 'evlist -g' > control

  terminal 1:
    {cycles,instructions}
    dummy:HG

  terminal 2:
    # echo 'evlist -F' > control

  terminal 1:
    cycles: sample_freq=4000
    instructions: sample_freq=4000
    dummy:HG: sample_freq=4000

This new evlist command is handy to get real event names when
wildcards are used.

Adding evsel_fprintf.c object to python/perf.so build, because
it's now evlist.c dependency.

Adding PYTHON_PERF define for python/perf.so compilation, so we
can use it to compile in only evsel__fprintf from evsel_fprintf.c
object.

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201226232038.390883-3-jolsa@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 991ae4eb

tools/perf/Documentation/perf-record.txt

+10 −5
Original line number Diff line number Diff line
@@ -652,6 +652,11 @@ Available commands: 
  'disable name'     : disable event 'name'

  'snapshot'         : AUX area tracing snapshot).



  'evlist [-v|-g|-F] : display all events

                       -F  Show just the sample frequency used for each event.

                       -v  Show all fields.

                       -g  Show event group information.



Measurements can be started with events disabled using --delay=-1 option. Optionally

send control command completion ('ack\n') to ack-fd descriptor to synchronize with the

controlling process.  Example of bash shell script to enable and disable events during

tools/perf/builtin-record.c

+1 −0
Original line number Diff line number Diff line
@@ -1946,6 +1946,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) 
			case EVLIST_CTL_CMD_UNSUPPORTED:

			case EVLIST_CTL_CMD_ENABLE:

			case EVLIST_CTL_CMD_DISABLE:

			case EVLIST_CTL_CMD_EVLIST:

			default:

				break;

			}

tools/perf/builtin-stat.c

+1 −0
Original line number Diff line number Diff line
@@ -621,6 +621,7 @@ static void process_evlist(struct evlist *evlist, unsigned int interval) 
		case EVLIST_CTL_CMD_SNAPSHOT:

		case EVLIST_CTL_CMD_ACK:

		case EVLIST_CTL_CMD_UNSUPPORTED:

		case EVLIST_CTL_CMD_EVLIST:

		default:

			break;

		}

tools/perf/util/evlist.c

+41 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include "bpf-event.h"

#include "util/string2.h"

#include "util/perf_api_probe.h"

#include "util/evsel_fprintf.h"

#include <signal.h>

#include <unistd.h>

#include <sched.h>
@@ -1936,6 +1937,9 @@ static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd, 
				    (sizeof(EVLIST_CTL_CMD_SNAPSHOT_TAG)-1))) {

			*cmd = EVLIST_CTL_CMD_SNAPSHOT;

			pr_debug("is snapshot\n");

		} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_EVLIST_TAG,

				    (sizeof(EVLIST_CTL_CMD_EVLIST_TAG)-1))) {

			*cmd = EVLIST_CTL_CMD_EVLIST;

		}

	}
@@ -2015,6 +2019,40 @@ static int evlist__ctlfd_enable(struct evlist *evlist, char *cmd_data, bool enab 
	return 0;

}



static int evlist__ctlfd_list(struct evlist *evlist, char *cmd_data)

{

	struct perf_attr_details details = { .verbose = false, };

	struct evsel *evsel;

	char *arg;

	int err;



	err = get_cmd_arg(cmd_data,

			  sizeof(EVLIST_CTL_CMD_EVLIST_TAG) - 1,

			  &arg);

	if (err < 0) {

		pr_info("failed: wrong command\n");

		return -1;

	}



	if (err) {

		if (!strcmp(arg, "-v")) {

			details.verbose = true;

		} else if (!strcmp(arg, "-g")) {

			details.event_group = true;

		} else if (!strcmp(arg, "-F")) {

			details.freq = true;

		} else {

			pr_info("failed: wrong command\n");

			return -1;

		}

	}



	evlist__for_each_entry(evlist, evsel)

		evsel__fprintf(evsel, &details, stderr);



	return 0;

}



int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd)

{

	int err = 0;
@@ -2035,6 +2073,9 @@ int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd) 
				err = evlist__ctlfd_enable(evlist, cmd_data,

							   *cmd == EVLIST_CTL_CMD_ENABLE);

				break;

			case EVLIST_CTL_CMD_EVLIST:

				err = evlist__ctlfd_list(evlist, cmd_data);

				break;

			case EVLIST_CTL_CMD_SNAPSHOT:

				break;

			case EVLIST_CTL_CMD_ACK:

tools/perf/util/evlist.h

+2 −0
Original line number Diff line number Diff line
@@ -330,6 +330,7 @@ struct evsel *evlist__reset_weak_group(struct evlist *evlist, struct evsel *evse 
#define EVLIST_CTL_CMD_DISABLE_TAG "disable"

#define EVLIST_CTL_CMD_ACK_TAG     "ack\n"

#define EVLIST_CTL_CMD_SNAPSHOT_TAG "snapshot"

#define EVLIST_CTL_CMD_EVLIST_TAG "evlist"



#define EVLIST_CTL_CMD_MAX_LEN 64
@@ -339,6 +340,7 @@ enum evlist_ctl_cmd { 
	EVLIST_CTL_CMD_DISABLE,

	EVLIST_CTL_CMD_ACK,

	EVLIST_CTL_CMD_SNAPSHOT,

	EVLIST_CTL_CMD_EVLIST,

};



int evlist__parse_control(const char *str, int *ctl_fd, int *ctl_fd_ack, bool *ctl_fd_close);