Re: [PATCH v2 11/15] perf ftrace: add support for trace option funcgraph-irqs

[Namhyung Kim]

On Sat, Jun 27, 2020 at 10:38 PM Changbin Du <changbin.du@xxxxxxxxx> wrote:
>
> This adds an option '--graph-noirqs' to filter out functions executed
> in irq context.

Ditto.

>
> Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
>
> ---
> v2: option name '--nofuncgraph-irqs' -> '--graph-noirqs'.
> ---
>  tools/perf/Documentation/perf-ftrace.txt |  3 +++
>  tools/perf/builtin-ftrace.c              | 20 ++++++++++++++++++++
>  2 files changed, 23 insertions(+)
>
> diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
> index a3000436f80b..b616e05d5156 100644
> --- a/tools/perf/Documentation/perf-ftrace.txt
> +++ b/tools/perf/Documentation/perf-ftrace.txt
> @@ -107,6 +107,9 @@ OPTIONS
>  --graph-nosleep-time::
>         Measure on-CPU time only for function_graph tracer.
>
> +--graph-noirqs::
> +       Ignore functions that happen inside interrupt for function_graph tracer.
> +
>  SEE ALSO
>  --------
>  linkperf:perf-record[1], linkperf:perf-trace[1]
> diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> index eba125a60820..876c8e800425 100644
> --- a/tools/perf/builtin-ftrace.c
> +++ b/tools/perf/builtin-ftrace.c
> @@ -43,6 +43,7 @@ struct perf_ftrace {
>         bool                    inherit;
>         bool                    func_stack_trace;
>         bool                    graph_nosleep_time;
> +       bool                    graph_noirqs;
>  };
>
>  struct filter_entry {
> @@ -202,6 +203,7 @@ static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
>         write_tracing_option_file("function-fork", "0");
>         write_tracing_option_file("func_stack_trace", "0");
>         write_tracing_option_file("sleep-time", "1");
> +       write_tracing_option_file("funcgraph-irqs", "1");
>  }
>
>  static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
> @@ -393,6 +395,17 @@ static int set_tracing_sleep_time(struct perf_ftrace *ftrace)
>         return 0;
>  }
>
> +static int set_tracing_funcgraph_irqs(struct perf_ftrace *ftrace)
> +{
> +       if (!ftrace->graph_noirqs)
> +               return 0;
> +
> +       if (write_tracing_option_file("funcgraph-irqs", "0") < 0)
> +               return -1;
> +
> +       return 0;
> +}
> +
>  static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
>  {
>         char *trace_file;
> @@ -477,6 +490,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
>                 goto out_reset;
>         }
>
> +       if (set_tracing_funcgraph_irqs(ftrace) < 0) {
> +               pr_err("failed to set tracing option funcgraph-irqs\n");
> +               goto out_reset;
> +       }

Why not add set_tracing_options() which calls these individual functions
to handle option processing altogether?  It seems consistent to its
'reset' counterpart.

Thanks
Namhyung


> +
>         if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
>                 pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
>                 goto out_reset;
> @@ -658,6 +676,8 @@ int cmd_ftrace(int argc, const char **argv)
>                     "trace children processes"),
>         OPT_BOOLEAN(0, "graph-nosleep-time", &ftrace.graph_nosleep_time,
>                     "measure on-CPU time only for function_graph tracer"),
> +       OPT_BOOLEAN(0, "graph-noirqs", &ftrace.graph_noirqs,
> +                   "ignore functions that happen inside interrupt for function_graph tracer"),
>         OPT_END()
>         };
>
> --
> 2.25.1
>