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

[Jiri Olsa <jolsa@kernel.org>]

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@kernel.org>
---
 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