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-info.c b/tools/perf/util/trace-event-info.c
index d995743..ceb0e272 100644
--- a/tools/perf/util/trace-event-info.c
+++ b/tools/perf/util/trace-event-info.c
@@ -42,7 +42,7 @@
#include "evsel.h"
#include "debug.h"
-#define VERSION "0.5"
+#define VERSION "0.6"
static int output_fd;
@@ -379,6 +379,34 @@ static int record_ftrace_printk(void)
return err;
}
+static int record_saved_cmdline(void)
+{
+ unsigned int size;
+ char *path;
+ struct stat st;
+ int ret, err = 0;
+
+ path = get_tracing_file("saved_cmdlines");
+ if (!path) {
+ pr_debug("can't get tracing/saved_cmdline");
+ return -ENOMEM;
+ }
+
+ ret = stat(path, &st);
+ if (ret < 0) {
+ /* not found */
+ size = 0;
+ if (write(output_fd, &size, 8) != 8)
+ err = -EIO;
+ goto out;
+ }
+ err = record_file(path, 8);
+
+out:
+ put_tracing_file(path);
+ return err;
+}
+
static void
put_tracepoints_path(struct tracepoint_path *tps)
{
@@ -539,6 +567,9 @@ struct tracing_data *tracing_data_get(struct list_head *pattrs,
if (err)
goto out;
err = record_ftrace_printk();
+ if (err)
+ goto out;
+ err = record_saved_cmdline();
out:
/*
