Adding control 'ping' command to detect if perf is up and
control interface is operational.
It will be used in following daemon patches to synchronize
with record session - when control interface is up and
running, we know that perf record is monitoring and ready
to receive signals.
Example session:
terminal 1:
# mkfifo control ack
# perf record --control=fifo:control,ack
terminal 2:
# echo ping > control
# cat ack
ack
Signed-off-by: Jiri Olsa <jo...@kernel.org>
---
tools/perf/Documentation/perf-record.txt | 1 +
tools/perf/builtin-record.c | 1 +
tools/perf/builtin-stat.c | 1 +
tools/perf/util/evlist.c | 4 ++++
tools/perf/util/evlist.h | 2 ++
5 files changed, 9 insertions(+)
diff --git a/tools/perf/Documentation/perf-record.txt
b/tools/perf/Documentation/perf-record.txt
index 539230955dbc..aa2da60ff12b 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -646,6 +646,7 @@ Available commands:
'disable name' : disable event 'name'
'snapshot' : AUX area tracing snapshot).
'stop' : stop perf record
+ 'ping' : ping
'evlist [-v|-g|-F] : display all events
-F Show just the sample frequency used for each event.
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 9aa051c3c722..3de81453ff8a 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1949,6 +1949,7 @@ static int __cmd_record(struct record *rec, int argc,
const char **argv)
case EVLIST_CTL_CMD_ENABLE:
case EVLIST_CTL_CMD_DISABLE:
case EVLIST_CTL_CMD_EVLIST:
+ case EVLIST_CTL_CMD_PING:
default:
break;
}
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 5681cbabbec5..d5d08ffae31b 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -590,6 +590,7 @@ static void process_evlist(struct evlist *evlist, unsigned
int interval)
case EVLIST_CTL_CMD_UNSUPPORTED:
case EVLIST_CTL_CMD_EVLIST:
case EVLIST_CTL_CMD_STOP:
+ case EVLIST_CTL_CMD_PING:
default:
break;
}
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index c6de70cefbae..61b2408821e5 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1943,6 +1943,9 @@ static int evlist__ctlfd_recv(struct evlist *evlist, enum
evlist_ctl_cmd *cmd,
} else if (!strncmp(cmd_data, EVLIST_CTL_CMD_STOP_TAG,
(sizeof(EVLIST_CTL_CMD_STOP_TAG)-1))) {
*cmd = EVLIST_CTL_CMD_STOP;
+ } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_PING_TAG,
+ (sizeof(EVLIST_CTL_CMD_PING_TAG)-1))) {
+ *cmd = EVLIST_CTL_CMD_PING;
}
}
@@ -2081,6 +2084,7 @@ int evlist__ctlfd_process(struct evlist *evlist, enum
evlist_ctl_cmd *cmd)
break;
case EVLIST_CTL_CMD_SNAPSHOT:
case EVLIST_CTL_CMD_STOP:
+ case EVLIST_CTL_CMD_PING:
break;
case EVLIST_CTL_CMD_ACK:
case EVLIST_CTL_CMD_UNSUPPORTED:
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 6f45c3630355..7c2521cb6b09 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -332,6 +332,7 @@ struct evsel *evlist__reset_weak_group(struct evlist
*evlist, struct evsel *evse
#define EVLIST_CTL_CMD_SNAPSHOT_TAG "snapshot"
#define EVLIST_CTL_CMD_EVLIST_TAG "evlist"
#define EVLIST_CTL_CMD_STOP_TAG "stop"
+#define EVLIST_CTL_CMD_PING_TAG "ping"
#define EVLIST_CTL_CMD_MAX_LEN 64
@@ -343,6 +344,7 @@ enum evlist_ctl_cmd {
EVLIST_CTL_CMD_SNAPSHOT,
EVLIST_CTL_CMD_EVLIST,
EVLIST_CTL_CMD_STOP,
+ EVLIST_CTL_CMD_PING,
};
int evlist__parse_control(const char *str, int *ctl_fd, int *ctl_fd_ack, bool
*ctl_fd_close);
--
2.26.2
