[PATCH 14/24] perf daemon: Set control fifo for session

[Jiri Olsa]

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 <jo...@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 4ebeb524b16e..d7b3dd1e96f9 100644
--- a/tools/perf/builtin-daemon.c
+++ b/tools/perf/builtin-daemon.c
@@ -30,6 +30,8 @@
 #include "util.h"
 
 #define SESSION_OUTPUT  "output"
+#define SESSION_CONTROL "control"
+#define SESSION_ACK     "ack"
 
 /*
  * Session states:
@@ -72,6 +74,7 @@ struct session {
        char                    *base;
        char                    *name;
        char                    *run;
+       char                    *control;
        int                      pid;
        struct list_head         list;
        enum session_state       state;
@@ -348,7 +351,18 @@ 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: create control fifo");
+               return -1;
+       }
+
+       if (mkfifo(SESSION_ACK, O_RDWR) && errno != EEXIST) {
+               perror("failed: 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)
@@ -562,6 +576,12 @@ 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",
@@ -572,6 +592,10 @@ 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);
                }
        }
 
-- 
2.29.2