[PATCH 13/22] perf daemon: Set control fifo for session

From: Jiri Olsa
Date: Sat Jan 02 2021 - 17:06:32 EST


Setup control fifos for session and add --control
option to session arguments.

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

Use can list control fifos with (control and ack files):

# perf daemon -v
[776459:daemon] base: /opt/perfdata
output: /opt/perfdata/output
lock: /opt/perfdata/lock
[776460:cycles] perf record -m 20M -e cycles --overwrite --switch-output -a
base: /opt/perfdata/session-cycles
output: /opt/perfdata/session-cycles/output
control: /opt/perfdata/session-cycles/control
ack: /opt/perfdata/session-cycles/ack
[776461:sched] perf record -m 20M -e sched:* --overwrite --switch-output -a
base: /opt/perfdata/session-sched
output: /opt/perfdata/session-sched/output
control: /opt/perfdata/session-sched/control
ack: /opt/perfdata/session-sched/ack

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/perf/builtin-daemon.c | 26 +++++++++++++++++++++++++-
1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-daemon.c b/tools/perf/builtin-daemon.c
index 1982eedd3f3f..0c82fe9603e8 100644
--- a/tools/perf/builtin-daemon.c
+++ b/tools/perf/builtin-daemon.c
@@ -35,6 +35,8 @@
#include <sys/signalfd.h>

#define SESSION_OUTPUT "output"
+#define SESSION_CONTROL "control"
+#define SESSION_ACK "ack"

enum session_state {
SESSION_STATE__OK,
@@ -46,6 +48,7 @@ struct session {
char *base;
char *name;
char *run;
+ char *control;
int pid;
struct list_head list;
enum session_state state;
@@ -288,7 +291,18 @@ static int session__run(struct session *session, struct daemon *daemon)
dup2(fd, 2);
close(fd);

- scnprintf(buf, sizeof(buf), "%s record %s", daemon->perf, session->run);
+ if (mkfifo(SESSION_CONTROL, O_RDWR) && errno != EEXIST) {
+ perror("failed to create control fifo");
+ return -1;
+ }
+
+ if (mkfifo(SESSION_ACK, O_RDWR) && errno != EEXIST) {
+ perror("failed to create ack fifo");
+ return -1;
+ }
+
+ scnprintf(buf, sizeof(buf), "%s record --control=fifo:%s,%s %s",
+ daemon->perf, SESSION_CONTROL, SESSION_ACK, session->run);

argv = argv_split(buf, &argc);
if (!argv)
@@ -594,6 +608,12 @@ static int cmd_session_list(struct daemon *daemon, union cmd *cmd, FILE *out)
/* session output */
csv_sep, session->base, SESSION_OUTPUT);

+ fprintf(out, "%c%s/%s%c%s/%s",
+ /* session control */
+ csv_sep, session->base, SESSION_CONTROL,
+ /* session ack */
+ csv_sep, session->base, SESSION_ACK);
+
fprintf(out, "\n");
} else {
fprintf(out, "[%d:%s] perf record %s\n",
@@ -604,6 +624,10 @@ static int cmd_session_list(struct daemon *daemon, union cmd *cmd, FILE *out)
session->base);
fprintf(out, " output: %s/%s\n",
session->base, SESSION_OUTPUT);
+ fprintf(out, " control: %s/%s\n",
+ session->base, SESSION_CONTROL);
+ fprintf(out, " ack: %s/%s\n",
+ session->base, SESSION_ACK);
}
}

--
2.26.2