perf daemon: Set control fifo for session

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>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: https://lore.kernel.org/r/20210208200908.1019149-15-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/Documentation/perf-daemon.txt b/tools/perf/Documentation/perf-daemon.txt
index 3c9e265..b1acd46 100644 (file)
--- a/tools/perf/Documentation/perf-daemon.txt
+++ b/tools/perf/Documentation/perf-daemon.txt
@@ -37,6 +37,9 @@ flight recorder sessions in above example or session that is configured
 to produce data periodically, like with --switch-output configuration
 for time and size.
 
+Each session is started with control setup (with perf record --control
+options).
+
 OPTIONS
 -------
 -v::

diff --git a/tools/perf/builtin-daemon.c b/tools/perf/builtin-daemon.c
index 2890573..2c5e68b 100644 (file)
--- a/tools/perf/builtin-daemon.c
+++ b/tools/perf/builtin-daemon.c
@@ -32,6 +32,8 @@
 #include "util.h"
 
 #define SESSION_OUTPUT  "output"
+#define SESSION_CONTROL "control"
+#define SESSION_ACK     "ack"
 
 /*
  * Session states:
@@ -74,6 +76,7 @@ struct daemon_session {
        char                            *base;
        char                            *name;
        char                            *run;
+       char                            *control;
        int                              pid;
        struct list_head                 list;
        enum daemon_session_state        state;
@@ -365,7 +368,18 @@ static int daemon_session__run(struct daemon_session *session,
        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)
@@ -603,6 +617,12 @@ 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",
@@ -613,6 +633,10 @@ 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);
                }
        }