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

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 cmd_record.

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

Signed-off-by David Ahern <[email protected]>

CC Arnaldo Carvalho de Melo <[email protected]>

Cc Ingo Molnar <[email protected]>

Cc Jiri Olsa <[email protected]>

Cc Namhyung Kim <[email protected]>

Cc Stephane Eranian <[email protected]>

Cc Frederic Weisbecker <[email protected]>

Cc Peter Zijlstra <[email protected]>

---
 tools/perf/builtin-kmem.c      |    2 ++
 tools/perf/builtin-kvm.c       |    2 ++
 tools/perf/builtin-lock.c      |    2 ++
 tools/perf/builtin-sched.c     |    2 ++
 tools/perf/builtin-script.c    |    2 ++
 tools/perf/builtin-timechart.c |    2 ++
 tools/perf/util/header.c       |    9 +++++++++
 7 files changed, 21 insertions(+)

tools/perf/builtin-kmem.c +2 -0

index ce35015..08c8f74 100644
@@ -770,6 +770,8 @@ static int __cmd_record(int argc, const char **argv)
 
 int cmd_kmem(int argc, const char **argv, const char *prefix __used)
 {
+       perf_header__set_cmdline(argc, argv);
+
        argc = parse_options(argc, argv, kmem_options, kmem_usage, 0);
 
        if (!argc)

tools/perf/builtin-kvm.c +2 -0

index 9fc6e0f..913d0a8 100644
@@ -107,6 +107,8 @@ int cmd_kvm(int argc, const char **argv, const char *prefix __used)
        perf_host  = 0;
        perf_guest = 1;
 
+       perf_header__set_cmdline(argc, argv);
+
        argc = parse_options(argc, argv, kvm_options, kvm_usage,
                        PARSE_OPT_STOP_AT_NON_OPTION);
        if (!argc)

tools/perf/builtin-lock.c +2 -0

index b3c4285..89917e1 100644
@@ -980,6 +980,8 @@ int cmd_lock(int argc, const char **argv, const char *prefix __used)
        for (i = 0; i < LOCKHASH_SIZE; i++)
                INIT_LIST_HEAD(lockhash_table + i);
 
+       perf_header__set_cmdline(argc, argv);
+
        argc = parse_options(argc, argv, lock_options, lock_usage,
                             PARSE_OPT_STOP_AT_NON_OPTION);
        if (!argc)

tools/perf/builtin-sched.c +2 -0

index 7a9ad2b..25113b2 100644
@@ -1899,6 +1899,8 @@ static int __cmd_record(int argc, const char **argv)
 
 int cmd_sched(int argc, const char **argv, const char *prefix __used)
 {
+       perf_header__set_cmdline(argc, argv);
+
        argc = parse_options(argc, argv, sched_options, sched_usage,
                             PARSE_OPT_STOP_AT_NON_OPTION);
        if (!argc)

tools/perf/builtin-script.c +2 -0

index 1e60ab7..07bc60b 100644
@@ -1206,6 +1206,8 @@ int cmd_script(int argc, const char **argv, const char *prefix __used)
 
        setup_scripting();
 
+       perf_header__set_cmdline(argc, argv);
+
        argc = parse_options(argc, argv, options, script_usage,
                             PARSE_OPT_STOP_AT_NON_OPTION);
 

tools/perf/builtin-timechart.c +2 -0

index 3b75b2e..1e776a6 100644
@@ -1108,6 +1108,8 @@ static const struct option options[] = {
 
 int cmd_timechart(int argc, const char **argv, const char *prefix __used)
 {
+       perf_header__set_cmdline(argc, argv);
+
        argc = parse_options(argc, argv, options, timechart_usage,
                        PARSE_OPT_STOP_AT_NON_OPTION);
 

tools/perf/util/header.c +9 -1

index 5a47aba..99e410c 100644
@@ -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 */
--

1.7.10.1

On Tue, Jul 3, 2012 at 6:08 AM, David Ahern <[email protected]> wrote:
Yes, you need to manually add the pfm_header__set_cmdline(). That begs

the question
as to whether or not it would not be better to move this call directly into the parse_option() function given that it must be done BEFORE parsing actually takes place.That way we would be sure all present and future commands would be covered.