Re: [PATCH 09/19] perf ftrace: add support for trace option tracing_thresh

From: Arnaldo Carvalho de Melo
Date: Wed May 20 2020 - 17:03:16 EST


Em Sun, May 10, 2020 at 11:06:18PM +0800, Changbin Du escreveu:
> This adds an option '--tracing-thresh' to setup trace duration threshold
> for funcgraph tracer.

Ditto

> Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
> ---
> tools/perf/builtin-ftrace.c | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> index f11f2d3431b0..20bc14d6c5fb 100644
> --- a/tools/perf/builtin-ftrace.c
> +++ b/tools/perf/builtin-ftrace.c
> @@ -43,6 +43,7 @@ struct perf_ftrace {
> bool nosleep_time;
> bool nofuncgraph_irqs;
> bool long_info;
> + unsigned tracing_thresh;
> };
>
> struct filter_entry {
> @@ -213,6 +214,9 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
> if (write_tracing_file("max_graph_depth", "0") < 0)
> return -1;
>
> + if (write_tracing_file("tracing_thresh", "0") < 0)
> + return -1;
> +
> reset_tracing_filters();
> reset_tracing_options(ftrace);
> return 0;
> @@ -392,6 +396,21 @@ static int set_tracing_long_info(struct perf_ftrace *ftrace)
> return 0;
> }
>
> +static int set_tracing_thresh(struct perf_ftrace *ftrace)
> +{
> + char buf[16];
> +
> + if (ftrace->tracing_thresh == 0)
> + return 0;
> +
> + snprintf(buf, sizeof(buf), "%d", ftrace->tracing_thresh);
> +
> + if (write_tracing_file("tracing_thresh", buf) < 0)
> + return -1;
> +
> + return 0;
> +}
> +
> static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
> {
> char *trace_file;
> @@ -475,6 +494,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
> goto out_reset;
> }
>
> + if (set_tracing_thresh(ftrace) < 0) {
> + pr_err("failed to set tracing thresh\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;
> @@ -616,6 +640,8 @@ int cmd_ftrace(int argc, const char **argv)
> "Ignore functions that happen inside interrupt (function_graph only)"),
> OPT_BOOLEAN('l', "long-info", &ftrace.long_info,
> "Show process names, PIDs, timestamps, irq-info if available"),
> + OPT_UINTEGER(0, "tracing-thresh", &ftrace.tracing_thresh,
> + "Only show functions of which the duration is greater than <n>µs"),
> OPT_END()
> };
>
> --
> 2.25.1
>

--

- Arnaldo