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

From: Arnaldo Carvalho de Melo
Date: Fri Jul 06 2012 - 13:17:41 EST


Em Thu, Jul 05, 2012 at 10:09:22PM -0600, David Ahern escreveu:
> 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.

Can you please state for what branch, perf/urgent (i.e. current merge
window) or perf/core (next), this is intended? I usually have been
making the call, but having feedback from the submitter can help things
and help meet expectations more frequently.

I'd say this one should be for perf/core, as it is not so critical, what
do you think?

- Arnaldo

> 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)) {
> case PARSE_OPT_HELP:
> --
> 1.7.10.1
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