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

[Stephane Eranian]

On Tue, Jul 3, 2012 at 6:08 AM, David Ahern <dsahern@xxxxxxxxx> wrote:
> 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
>
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.


> 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-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(+)
>
> diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
> index ce35015..08c8f74 100644
> --- a/tools/perf/builtin-kmem.c
> +++ b/tools/perf/builtin-kmem.c
> @@ -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)
> diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
> index 9fc6e0f..913d0a8 100644
> --- a/tools/perf/builtin-kvm.c
> +++ b/tools/perf/builtin-kvm.c
> @@ -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)
> diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
> index b3c4285..89917e1 100644
> --- a/tools/perf/builtin-lock.c
> +++ b/tools/perf/builtin-lock.c
> @@ -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)
> diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> index 7a9ad2b..25113b2 100644
> --- a/tools/perf/builtin-sched.c
> +++ b/tools/perf/builtin-sched.c
> @@ -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)
> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index 1e60ab7..07bc60b 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -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);
>
> diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
> index 3b75b2e..1e776a6 100644
> --- a/tools/perf/builtin-timechart.c
> +++ b/tools/perf/builtin-timechart.c
> @@ -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);
>
> 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 */
> --
> 1.7.10.1
>
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