perf util: Save pid-cmdline mapping into tracing header
Current trace info data lacks the saved cmdline mapping which is needed
for pevent to find out the comm of a task. Add this and bump up the
version number so that perf can determine its presence when reading.
This is mostly corresponding to trace.dat file version 6, but still
lacks 4 byte of number of cpus, and 10 bytes of type string - and I
think we don't need those anyway.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jeremy Eder <jeder@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>,
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
[ Change version test from == to >= ]
Link: http://lkml.kernel.org/n/tip-vaooqpxsikxbb3359p0corcb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
index b67a0cc..61c7162 100644
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -341,6 +341,31 @@
return 0;
}
+static int read_saved_cmdline(struct pevent *pevent)
+{
+ unsigned long long size;
+ char *buf;
+
+ /* it can have 0 size */
+ size = read8(pevent);
+ if (!size)
+ return 0;
+
+ buf = malloc(size + 1);
+ if (buf == NULL)
+ return -1;
+
+ if (do_read(buf, size) < 0) {
+ free(buf);
+ return -1;
+ }
+
+ parse_saved_cmdline(pevent, buf, size);
+
+ free(buf);
+ return 0;
+}
+
ssize_t trace_report(int fd, struct trace_event *tevent, bool __repipe)
{
char buf[BUFSIZ];
@@ -379,10 +404,11 @@
return -1;
if (show_version)
printf("version = %s\n", version);
- free(version);
- if (do_read(buf, 1) < 0)
+ if (do_read(buf, 1) < 0) {
+ free(version);
return -1;
+ }
file_bigendian = buf[0];
host_bigendian = bigendian();
@@ -423,6 +449,11 @@
err = read_ftrace_printk(pevent);
if (err)
goto out;
+ if (atof(version) >= 0.6) {
+ err = read_saved_cmdline(pevent);
+ if (err)
+ goto out;
+ }
size = trace_data_size;
repipe = false;
@@ -438,5 +469,6 @@
out:
if (pevent)
trace_event__cleanup(tevent);
+ free(version);
return size;
}