[PATCH 11/24] perf daemon: Add signal command

From: Jiri Olsa
Date: Mon Feb 08 2021 - 16:14:40 EST


Allow 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

Starting 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: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/perf/Documentation/perf-daemon.txt | 9 +++
tools/perf/builtin-daemon.c | 75 +++++++++++++++++++++---
2 files changed, 77 insertions(+), 7 deletions(-)

diff --git a/tools/perf/Documentation/perf-daemon.txt b/tools/perf/Documentation/perf-daemon.txt
index af5916d1c3e0..9cd47ec959e9 100644
--- a/tools/perf/Documentation/perf-daemon.txt
+++ b/tools/perf/Documentation/perf-daemon.txt
@@ -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
diff --git a/tools/perf/builtin-daemon.c b/tools/perf/builtin-daemon.c
index 8a0994b0dfce..027e1e58b67b 100644
--- a/tools/perf/builtin-daemon.c
+++ b/tools/perf/builtin-daemon.c
@@ -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)
{
@@ -1090,6 +1121,34 @@ 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[] = {
@@ -1112,6 +1171,8 @@ 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;
--
2.29.2