Re: [PATCH 5/8] perf daemon: Add signal command

[Jiri Olsa]

On Tue, Dec 15, 2020 at 12:45:21PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Sat, Dec 12, 2020 at 11:43:55AM +0100, Jiri Olsa escreveu:
> > Allow perf daemon to send SIGUSR2 to all running sessions:
> > 
> >   # perf daemon
> >   [1:364758] perf record -m 10M -e cycles -o /opt/perfdata/1/perf.data --overwrite --switch-output -a
> >   [2:364759] perf record -m 10M -e sched:* -o /opt/perfdata/2/perf.data --overwrite --switch-output -a
> 
> The above looks ambiguous, is it starting those sessions at this point
> or is it checking if there is a running daemon and then listing its
> sessions?

so 'perf daemon --config <CONFIGFILE>' runs daemon based
on CONFIGFILE settings

perf daemon <other options> reads standard .perfconfig and
expects:

  [daemon]
  base=PATH

and tries to connect to daemon that runs on top of PATH

I think --base should be also command line option

jirka

> 
> - Arnaldo
>  
> >   # perf daemon -s
> >   signal 12 sent to session '1 [92187]'
> >   signal 12 sent to session '2 [92188]'
> > 
> > Or to specific one:
> > 
> >   # perf daemon --signal=1
> >   signal 12 sent to session '1 [364758]'
> > 
> > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> > ---
> >  tools/perf/Documentation/perf-daemon.txt | 24 +++++++++++
> >  tools/perf/builtin-daemon.c              | 51 +++++++++++++++++++++++-
> >  2 files changed, 73 insertions(+), 2 deletions(-)
> > 
> > diff --git a/tools/perf/Documentation/perf-daemon.txt b/tools/perf/Documentation/perf-daemon.txt
> > index dee39be110ba..203ec4bf704c 100644
> > --- a/tools/perf/Documentation/perf-daemon.txt
> > +++ b/tools/perf/Documentation/perf-daemon.txt
> > @@ -30,6 +30,11 @@ OPTIONS
> >  --foreground::
> >  	Do not put the process in background.
> >  
> > +-s::
> > +--signal[=session]::
> > +	Send SIGUSR2 to specific session, if session is not specified,
> > +	send SIGUSR2 to all sessions.
> > +
> >  -v::
> >  --verbose::
> >  	Be more verbose.
> > @@ -92,6 +97,25 @@ Check sessions with more info:
> >  The 'output' file is perf record output for specific session.
> >  
> >  
> > +Send SIGUSR2 signal to all sessions:
> > +
> > +  # perf daemon -s
> > +  signal 12 sent to session '1 [92187]'
> > +  signal 12 sent to session '2 [92188]'
> > +
> > +Send SIGUSR2 signal to session '1':
> > +
> > +  # perf daemon --signal=1
> > +  signal 12 sent to session '1 [364758]'
> > +
> > +And check that the perf data dump was trigered:
> > +
> > +  # cat /opt/perfdata/2/output
> > +  rounding mmap pages size to 32M (8192 pages)
> > +  [ perf record: dump data: Woken up 1 times ]
> > +  [ perf record: Dump /opt/perfdata/2/perf.data.2020120715220385 ]
> > +
> > +
> >  SEE ALSO
> >  --------
> >  linkperf:perf-record[1], linkperf:perf-config[1]
> > diff --git a/tools/perf/builtin-daemon.c b/tools/perf/builtin-daemon.c
> > index 7f455837d58a..c53d4ddc2b49 100644
> > --- a/tools/perf/builtin-daemon.c
> > +++ b/tools/perf/builtin-daemon.c
> > @@ -450,9 +450,15 @@ static int setup_server_socket(struct daemon *daemon)
> >  enum cmd {
> >  	CMD_LIST         = 0,
> >  	CMD_LIST_VERBOSE = 1,
> > +	CMD_SIGNAL       = 2,
> >  	CMD_MAX,
> >  };
> >  
> > +struct cmd_signal {
> > +	int	sig;
> > +	char	name[16];
> > +};
> > +
> >  static int cmd_session_list(struct daemon *daemon, FILE *out, bool simple)
> >  {
> >  	struct session *session;
> > @@ -469,6 +475,28 @@ static int cmd_session_list(struct daemon *daemon, FILE *out, bool simple)
> >  	return 0;
> >  }
> >  
> > +static int cmd_session_kill(struct daemon *daemon, FILE *out, int fd)
> > +{
> > +	struct session *session;
> > +	struct cmd_signal data;
> > +	bool all = false;
> > +
> > +	if (sizeof(data) != read(fd, &data, sizeof(data)))
> > +		return -1;
> > +
> > +	all = !strcmp(data.name, "all");
> > +
> > +	list_for_each_entry(session, &daemon->sessions, list) {
> > +		if (all || !strcmp(data.name, session->name)) {
> > +			session__signal(session, data.sig);
> > +			fprintf(out, "signal %d sent to session '%s [%d]'\n",
> > +				data.sig, session->name, session->pid);
> > +		}
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> >  static int handle_server_socket(struct daemon *daemon, int sock_fd)
> >  {
> >  	int ret = -EINVAL, fd;
> > @@ -497,6 +525,9 @@ static int handle_server_socket(struct daemon *daemon, int sock_fd)
> >  	case CMD_LIST_VERBOSE:
> >  		ret = cmd_session_list(daemon, out, cmd == CMD_LIST);
> >  		break;
> > +	case CMD_SIGNAL:
> > +		ret = cmd_session_kill(daemon, out, fd);
> > +		break;
> >  	default:
> >  		break;
> >  	}
> > @@ -730,8 +761,9 @@ static int __cmd_daemon(struct daemon *daemon, bool foreground, const char *conf
> >  	return err;
> >  }
> >  
> > -static int send_cmd(struct daemon *daemon, u64 cmd)
> > +static int send_cmd(struct daemon *daemon, u64 cmd, const char *str)
> >  {
> > +	struct cmd_signal data;
> >  	char *line = NULL;
> >  	size_t len = 0;
> >  	ssize_t nread;
> > @@ -747,6 +779,14 @@ static int send_cmd(struct daemon *daemon, u64 cmd)
> >  	if (sizeof(cmd) != write(fd, &cmd, sizeof(cmd)))
> >  		return -1;
> >  
> > +	if (cmd == CMD_SIGNAL) {
> > +		data.sig = SIGUSR2;
> > +		strncpy(data.name, str, sizeof(data.name) - 1);
> > +
> > +		if (sizeof(data) != write(fd, &data, sizeof(data)))
> > +			return -1;
> > +	}
> > +
> >  	in = fdopen(fd, "r");
> >  	if (!in) {
> >  		perror("fopen");
> > @@ -770,7 +810,9 @@ static const char * const daemon_usage[] = {
> >  int cmd_daemon(int argc, const char **argv)
> >  {
> >  	bool foreground = false;
> > +	bool signal = false;
> >  	const char *config = NULL;
> > +	const char *signal_str = NULL;
> >  	struct daemon daemon = {
> >  		.sessions = LIST_HEAD_INIT(daemon.sessions),
> >  		.out	  = stdout,
> > @@ -780,6 +822,8 @@ int cmd_daemon(int argc, const char **argv)
> >  		OPT_STRING(0, "config", &config,
> >  			   "config file", "config file path"),
> >  		OPT_BOOLEAN('f', "foreground", &foreground, "stay on console"),
> > +		OPT_STRING_OPTARG_SET('s', "signal", &signal_str, &signal,
> > +				      "signal", "send signal to session", "all"),
> >  		OPT_END()
> >  	};
> >  
> > @@ -790,5 +834,8 @@ int cmd_daemon(int argc, const char **argv)
> >  	if (config)
> >  		return __cmd_daemon(&daemon, foreground, config);
> >  
> > -	return send_cmd(&daemon, verbose ? CMD_LIST_VERBOSE : CMD_LIST);
> > +	if (signal)
> > +		return send_cmd(&daemon, CMD_SIGNAL, signal_str);
> > +
> > +	return send_cmd(&daemon, verbose ? CMD_LIST_VERBOSE : CMD_LIST, NULL);
> >  }
> > -- 
> > 2.26.2
> > 
> 
> -- 
> 
> - Arnaldo
>