Em Sat, Aug 08, 2020 at 10:31:32AM +0800, Changbin Du escreveu:
> This adds an option '--graph-opts nosleep-time' which allow us
> only to measure on-CPU time. This option is function_graph tracer
> only.
Here an example showing its usage would be great. Even better, on
perf-ftrace.txt, so that people can see it in action and learn about its
output and usefullness.
Applied,
- Arnaldo
> Signed-off-by: Changbin Du <changbin...@gmail.com>
>
> ---
> v3: switch to uniform option --graph-opts.
> v2: option name '--nosleep-time' -> '--graph-nosleep-time'.
> ---
> tools/perf/Documentation/perf-ftrace.txt | 4 +++
> tools/perf/builtin-ftrace.c | 41 ++++++++++++++++++++++++
> 2 files changed, 45 insertions(+)
>
> diff --git a/tools/perf/Documentation/perf-ftrace.txt
> b/tools/perf/Documentation/perf-ftrace.txt
> index 8f08ad0992c2..3380a2e2c9ad 100644
> --- a/tools/perf/Documentation/perf-ftrace.txt
> +++ b/tools/perf/Documentation/perf-ftrace.txt
> @@ -101,6 +101,10 @@ OPTIONS
> --graph-depth=::
> Set max depth for function graph tracer to follow
>
> +--graph-opts::
> + List of options allowed to set:
> + nosleep-time - Measure on-CPU time only 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 469b89748c42..47d63bba6a48 100644
> --- a/tools/perf/builtin-ftrace.c
> +++ b/tools/perf/builtin-ftrace.c
> @@ -44,6 +44,7 @@ struct perf_ftrace {
> unsigned long percpu_buffer_size;
> bool inherit;
> int func_stack_trace;
> + int graph_nosleep_time;
> };
>
> struct filter_entry {
> @@ -205,6 +206,7 @@ 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");
> }
>
> static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
> @@ -386,6 +388,17 @@ static int set_tracing_trace_inherit(struct perf_ftrace
> *ftrace)
> return 0;
> }
>
> +static int set_tracing_sleep_time(struct perf_ftrace *ftrace)
> +{
> + if (!ftrace->graph_nosleep_time)
> + return 0;
> +
> + if (write_tracing_option_file("sleep-time", "0") < 0)
> + return -1;
> +
> + return 0;
> +}
> +
> static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char
> **argv)
> {
> char *trace_file;
> @@ -465,6 +478,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int
> argc, const char **argv)
> goto out_reset;
> }
>
> + if (set_tracing_sleep_time(ftrace) < 0) {
> + pr_err("failed to set tracing option sleep-time\n");
> + goto out_reset;
> + }
> +
> if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
> pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
> goto out_reset;
> @@ -637,6 +655,26 @@ static int parse_func_tracer_opts(const struct option
> *opt,
> return 0;
> }
>
> +static int parse_graph_tracer_opts(const struct option *opt,
> + const char *str, int unset)
> +{
> + int ret;
> + struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
> + struct sublevel_option graph_tracer_opts[] = {
> + { .name = "nosleep-time", .value_ptr =
> &ftrace->graph_nosleep_time },
> + { .name = NULL, }
> + };
> +
> + if (unset)
> + return 0;
> +
> + ret = perf_parse_sublevel_options(str, graph_tracer_opts);
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> static void select_tracer(struct perf_ftrace *ftrace)
> {
> bool graph = !list_empty(&ftrace->graph_funcs) ||
> @@ -694,6 +732,9 @@ int cmd_ftrace(int argc, const char **argv)
> "Set nograph filter on given functions",
> parse_filter_func),
> OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth,
> "Max depth for function graph tracer"),
> + OPT_CALLBACK(0, "graph-opts", &ftrace, "options",
> + "graph tracer options, available options: nosleep-time",
> + parse_graph_tracer_opts),
> OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
> "size of per cpu buffer", parse_buffer_size),
> OPT_BOOLEAN(0, "inherit", &ftrace.inherit,
> --
> 2.25.1
>
--
- Arnaldo
