Re: [PATCH 4/5] perf tools: Add --debug optionto set debug variable

From: Namhyung Kim
Date: Thu Jul 17 2014 - 04:16:21 EST


Hi Jiri,

On Mon, 14 Jul 2014 23:46:50 +0200, Jiri Olsa wrote:
> Adding --debug option as a way to setup debug variables.
> Starting with support for verbose, more will come.
>
> It's possible to use it now with report command:
> $ perf --debug verbose ...
> $ perf --debug verbose=2 ...
>
> I'll need this support to add separated debug variable
> for ordered events change in order to separate debug
> output out of standard verbose stream.
>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx>
> Cc: David Ahern <dsahern@xxxxxxxxx>
> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> tools/perf/Documentation/perf-report.txt | 6 +++++
> tools/perf/Documentation/perf.txt | 10 +++++++-
> tools/perf/perf.c | 13 +++++++++-
> tools/perf/util/debug.c | 44 ++++++++++++++++++++++++++++++++
> tools/perf/util/debug.h | 2 ++
> 5 files changed, 73 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
> index d2b59af62bc0..53b6ad8e4d4d 100644
> --- a/tools/perf/Documentation/perf-report.txt
> +++ b/tools/perf/Documentation/perf-report.txt
> @@ -25,6 +25,12 @@ OPTIONS
> --verbose::
> Be more verbose. (show symbol address, etc)
>
> +--debug::
> + Setup debug variable (just verbose for now) in value
> + range (0, 10). Use like:
> + --debug verbose # sets verbose = 1
> + --debug verbose=2 # sets verbose = 2
> +
> -n::
> --show-nr-samples::
> Show the number of samples for each symbol
> diff --git a/tools/perf/Documentation/perf.txt b/tools/perf/Documentation/perf.txt
> index 0eeb247dc7d2..c75a42822c53 100644
> --- a/tools/perf/Documentation/perf.txt
> +++ b/tools/perf/Documentation/perf.txt
> @@ -8,7 +8,15 @@ perf - Performance analysis tools for Linux
> SYNOPSIS
> --------
> [verse]
> -'perf' [--version] [--help] COMMAND [ARGS]
> +'perf' [--version] [--debug variable[=VALUE]] [--help] COMMAND [ARGS]

Hmm.. is this really needed? Also, there're other options might be
added here. What about just saying

'perf' [--version] [--help] [OPTIONS] COMMAND [ARGS]

?

Thanks,
Namhyung


> +
> +OPTIONS
> +-------
> +--debug::
> + Setup debug variable (just verbose for now) in value
> + range (0, 10). Use like:
> + --debug verbose # sets verbose = 1
> + --debug verbose=2 # sets verbose = 2
>
> DESCRIPTION
> -----------
> diff --git a/tools/perf/perf.c b/tools/perf/perf.c
> index 95c58fc15284..eed3fb2a3af0 100644
> --- a/tools/perf/perf.c
> +++ b/tools/perf/perf.c
> @@ -13,11 +13,12 @@
> #include "util/quote.h"
> #include "util/run-command.h"
> #include "util/parse-events.h"
> +#include "util/debug.h"
> #include <api/fs/debugfs.h>
> #include <pthread.h>
>
> const char perf_usage_string[] =
> - "perf [--version] [--help] COMMAND [ARGS]";
> + "perf [--version] [--debug variable[=VALUE]] [--help] COMMAND [ARGS]";
>
> const char perf_more_info_string[] =
> "See 'perf help COMMAND' for more information on a specific command.";
> @@ -212,6 +213,16 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
> printf("%s ", p->cmd);
> }
> exit(0);
> + } else if (!strcmp(cmd, "--debug")) {
> + if (*argc < 2) {
> + fprintf(stderr, "No variable specified for --debug.\n");
> + usage(perf_usage_string);
> + }
> + if (perf_debug_option((*argv)[1]))
> + usage(perf_usage_string);
> +
> + (*argv)++;
> + (*argc)--;
> } else {
> fprintf(stderr, "Unknown option: %s\n", cmd);
> usage(perf_usage_string);
> diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
> index c208d6f56e63..71d419362634 100644
> --- a/tools/perf/util/debug.c
> +++ b/tools/perf/util/debug.c
> @@ -105,3 +105,47 @@ void trace_event(union perf_event *event)
> }
> printf(".\n");
> }
> +
> +static struct debug_variable {
> + const char *name;
> + int *ptr;
> +} debug_variables[] = {
> + { .name = "verbose", .ptr = &verbose },
> + { .name = NULL, }
> +};
> +
> +int perf_debug_option(const char *str)
> +{
> + struct debug_variable *var = &debug_variables[0];
> + char *vstr, *s = strdup(str);
> + int v = 1;
> +
> + vstr = strchr(s, '=');
> + if (vstr)
> + *vstr++ = 0;
> +
> + while (var->name) {
> + if (!strcmp(s, var->name))
> + break;
> + var++;
> + }
> +
> + if (!var->name) {
> + pr_err("Unknown debug variable name '%s'\n", s);
> + free(s);
> + return -1;
> + }
> +
> + if (vstr) {
> + v = atoi(vstr);
> + /*
> + * Allow only values in range (0, 10),
> + * otherwise set 0.
> + */
> + v = (v < 0) || (v > 10) ? 0 : v;
> + }
> +
> + *var->ptr = v;
> + free(s);
> + return 0;
> +}
> diff --git a/tools/perf/util/debug.h b/tools/perf/util/debug.h
> index 1cb808123242..89fb6b0f7ab2 100644
> --- a/tools/perf/util/debug.h
> +++ b/tools/perf/util/debug.h
> @@ -39,4 +39,6 @@ void pr_stat(const char *fmt, ...);
>
> int eprintf(int level, int var, const char *fmt, ...) __attribute__((format(printf, 3, 4)));
>
> +int perf_debug_option(const char *str);
> +
> #endif /* __PERF_DEBUG_H */
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