Commit 2d6914cd authored by Jiri Olsa's avatar Jiri Olsa Committed by Arnaldo Carvalho de Melo
Browse files

perf daemon: Add 'signal' command 



Allow the 'perf daemon' to send SIGUSR2 to all running sessions or just
to a specific session.

Example:

  # cat ~/.perfconfig
  [daemon]
  base=/opt/perfdata

  [session-cycles]
  run = -m 10M -e cycles --overwrite --switch-output -a

  [session-sched]
  run = -m 20M -e sched:* --overwrite --switch-output -a

Start the daemon:

  # perf daemon start

Send signal to all running sessions:

  # perf daemon signal
  signal 12 sent to session 'cycles [773738]'
  signal 12 sent to session 'sched [773739]'

Or to specific one:

  # perf daemon signal --session sched
  signal 12 sent to session 'sched [773739]'

And verify signals were delivered and perf.data dumped:

  # cat /opt/perfdata/session-cycles/output
  rounding mmap pages size to 32M (8192 pages)
  [ perf record: dump data: Woken up 1 times ]
  [ perf record: Dump perf.data.2021010220382490 ]

  # car /opt/perfdata/session-sched/output
  rounding mmap pages size to 32M (8192 pages)
  [ perf record: dump data: Woken up 1 times ]
  [ perf record: Dump perf.data.2021010220382489 ]
  [ perf record: dump data: Woken up 1 times ]
  [ perf record: Dump perf.data.2021010220393745 ]

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-12-jolsa@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent b325f7be

tools/perf/Documentation/perf-daemon.txt

+9 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ SYNOPSIS 
'perf daemon'

'perf daemon' [<options>]

'perf daemon start'  [<options>]

'perf daemon signal' [<options>]





DESCRIPTION
@@ -61,6 +62,14 @@ The start command creates the daemon process. 
	Do not put the process in background.





SIGNAL COMMAND

--------------

The signal command sends signal to configured sessions.



--session::

	Send signal to specific session.





CONFIG FILE

-----------

The daemon is configured within standard perf config file by

tools/perf/builtin-daemon.c

+68 −7
Original line number Diff line number Diff line
@@ -531,9 +531,12 @@ static int setup_server_socket(struct daemon *daemon) 


enum {

	CMD_LIST   = 0,

	CMD_SIGNAL = 1,

	CMD_MAX,

};



#define SESSION_MAX 64



union cmd {

	int cmd;
@@ -543,6 +546,13 @@ union cmd { 
		int	verbose;

		char	csv_sep;

	} list;



	/* CMD_SIGNAL */

	struct {

		int	cmd;

		int	sig;

		char	name[SESSION_MAX];

	} signal;

};



static int cmd_session_list(struct daemon *daemon, union cmd *cmd, FILE *out)
@@ -600,6 +610,31 @@ static int cmd_session_list(struct daemon *daemon, union cmd *cmd, FILE *out) 
	return 0;

}



static int daemon_session__signal(struct daemon_session *session, int sig)

{

	if (session->pid < 0)

		return -1;

	return kill(session->pid, sig);

}



static int cmd_session_kill(struct daemon *daemon, union cmd *cmd, FILE *out)

{

	struct daemon_session *session;

	bool all = false;



	all = !strcmp(cmd->signal.name, "all");



	list_for_each_entry(session, &daemon->sessions, list) {

		if (all || !strcmp(cmd->signal.name, session->name)) {

			daemon_session__signal(session, cmd->signal.sig);

			fprintf(out, "signal %d sent to session '%s [%d]'\n",

				cmd->signal.sig, session->name, session->pid);

		}

	}



	return 0;

}



static int handle_server_socket(struct daemon *daemon, int sock_fd)

{

	int ret = -1, fd;
@@ -627,6 +662,9 @@ static int handle_server_socket(struct daemon *daemon, int sock_fd) 
	case CMD_LIST:

		ret = cmd_session_list(daemon, &cmd, out);

		break;

	case CMD_SIGNAL:

		ret = cmd_session_kill(daemon, &cmd, out);

		break;

	default:

		break;

	}
@@ -671,13 +709,6 @@ static int setup_client_socket(struct daemon *daemon) 
	return fd;

}



static int daemon_session__signal(struct daemon_session *session, int sig)

{

	if (session->pid < 0)

		return -1;

	return kill(session->pid, sig);

}



static void daemon_session__kill(struct daemon_session *session,

				 struct daemon *daemon)

{
@@ -1092,6 +1123,34 @@ static int send_cmd_list(struct daemon *daemon) 
	return send_cmd(daemon, &cmd);

}



static int __cmd_signal(struct daemon *daemon, struct option parent_options[],

			int argc, const char **argv)

{

	const char *name = "all";

	struct option start_options[] = {

		OPT_STRING(0, "session", &name, "session",

			"Sent signal to specific session"),

		OPT_PARENT(parent_options),

		OPT_END()

	};

	union cmd cmd;



	argc = parse_options(argc, argv, start_options, daemon_usage, 0);

	if (argc)

		usage_with_options(daemon_usage, start_options);



	if (setup_config(daemon)) {

		pr_err("failed: config not found\n");

		return -1;

	}



	cmd.signal.cmd = CMD_SIGNAL,

	cmd.signal.sig = SIGUSR2;

	strncpy(cmd.signal.name, name, sizeof(cmd.signal.name) - 1);



	return send_cmd(daemon, &cmd);

}



int cmd_daemon(int argc, const char **argv)

{

	struct option daemon_options[] = {
@@ -1114,6 +1173,8 @@ int cmd_daemon(int argc, const char **argv) 
	if (argc) {

		if (!strcmp(argv[0], "start"))

			return __cmd_start(&__daemon, daemon_options, argc, argv);

		if (!strcmp(argv[0], "signal"))

			return __cmd_signal(&__daemon, daemon_options, argc, argv);



		pr_err("failed: unknown command '%s'\n", argv[0]);

		return -1;