perf: Convert perf tracing data into a tracing_data event

Bypasses the tracing_data perf header code and replaces it with
a synthesized event and processing function that accomplishes
the same thing, used when reading/writing perf data to/from a
pipe.

The tracing data is pretty large, and this patch doesn't attempt
to break it down into component events.  The tracing_data event
itself doesn't actually contain the tracing data, rather it
arranges for the event processing code to skip over it after
it's read, using the skip return value added to the event
processing loop in a previous patch.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: k-keiichi@bx.jp.nec.com
Cc: acme@ghostprotocols.net
LKML-Reference: <1270184365-8281-8-git-send-email-tzanussi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 24 insertions, 0 deletions

diff --git a/tools/perf/util/trace-event-info.c b/tools/perf/util/trace-event-info.c
index 5ea8973ad33..30cd9b57595 100644
--- a/tools/perf/util/trace-event-info.c
+++ b/tools/perf/util/trace-event-info.c
@@ -154,10 +154,17 @@ static void put_tracing_file(char *file)
 	free(file);
 }
 
+static ssize_t calc_data_size;
+
 static ssize_t write_or_die(const void *buf, size_t len)
 {
 	int ret;
 
+	if (calc_data_size) {
+		calc_data_size += len;
+		return len;
+	}
+
 	ret = write(output_fd, buf, len);
 	if (ret < 0)
 		die("writing to '%s'", output_file);
@@ -526,3 +533,20 @@ int read_tracing_data(int fd, struct perf_event_attr *pattrs, int nb_events)
 
 	return 0;
 }
+
+ssize_t read_tracing_data_size(int fd, struct perf_event_attr *pattrs,
+			       int nb_events)
+{
+	ssize_t size;
+	int err = 0;
+
+	calc_data_size = 1;
+	err = read_tracing_data(fd, pattrs, nb_events);
+	size = calc_data_size - 1;
+	calc_data_size = 0;
+
+	if (err < 0)
+		return err;
+
+	return size;
+}