[PATCH] perf tool: save cmdline from user in file header vs what is passed to record

From: David Ahern
Date: Fri Jul 06 2012 - 00:09:24 EST

A number of builtin commands process some user args and then pass the rest
to cmd_record. cmd_record then saves argc/argv that it receives into the
header of the perf data file. But this loses the arguments handled by the
first command -- ie., the real command line from the user. This patch saves
the command line as typed by the user rather than what was passed to

As an example consider the command:
$ perf kvm --guest --host --guestmount=/tmp/guest-mount record
-fo /tmp/perf.data -ag -- sleep 10

Currently the command saved to the header is:
cmdline : /tmp/p3.5/perf record -o perf.data.kvm -fo /tmp/perf.data -ag -- sleep 1

(ignore the duplicated -o -- the first would be yet another bug with perf-kvm).

With this patch the command line saved to the header is:
cmdline : /tmp/p3.5/perf kvm --guest --host --guestmount=/tmp/guest-mount
record -fo /tmp/perf.data -ag -- sleep 1

v2: simplified to saving the command in parse_options per Stephane's suggestion

Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
CC: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
tools/perf/builtin-record.c | 2 --
tools/perf/util/header.c | 9 +++++++++
tools/perf/util/parse-options.c | 3 +++
3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index f5a6452..77adcd8 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -844,8 +844,6 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
struct perf_record *rec = &record;
char errbuf[BUFSIZ];

- perf_header__set_cmdline(argc, argv);
evsel_list = perf_evlist__new(NULL, NULL);
if (evsel_list == NULL)
return -ENOMEM;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 5a47aba..99e410c 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -174,6 +174,15 @@ perf_header__set_cmdline(int argc, const char **argv)
int i;

+ /*
+ * If header_argv has already been set, do not override it.
+ * This allows a command to set the cmdline, parse args and
+ * then call another builtin function that implements a
+ * command -- e.g, cmd_kvm calling cmd_record.
+ */
+ if (header_argv)
+ return 0;
header_argc = (u32)argc;

/* do not include NULL termination */
diff --git a/tools/perf/util/parse-options.c b/tools/perf/util/parse-options.c
index 99d02aa..594f8fa 100644
--- a/tools/perf/util/parse-options.c
+++ b/tools/perf/util/parse-options.c
@@ -1,6 +1,7 @@
#include "util.h"
#include "parse-options.h"
#include "cache.h"
+#include "header.h"

#define OPT_SHORT 1
#define OPT_UNSET 2
@@ -413,6 +414,8 @@ int parse_options(int argc, const char **argv, const struct option *options,
struct parse_opt_ctx_t ctx;

+ perf_header__set_cmdline(argc, argv);
parse_options_start(&ctx, argc, argv, flags);
switch (parse_options_step(&ctx, options, usagestr)) {

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/