Re: [PATCH 18/19] perf ftrace: add option --latency-format to display more info about delay

From: Arnaldo Carvalho de Melo
Date: Wed May 20 2020 - 17:14:28 EST


Em Sun, May 10, 2020 at 11:06:27PM +0800, Changbin Du escreveu:
> This is for the function graph tracer to display more info about latency.
> The execution context is shown in this case.

Ok, another --function-graph-opts entry, maybe you can just make -G
receive optional args.

- Arnaldo

> $ sudo perf ftrace -G --latency-format
> \# tracer: function_graph
> \#
> 1) .... | 0.992 us | mutex_unlock();
> 1) .... | 1.404 us | __fsnotify_parent();
> 1) .... | 1.023 us | fsnotify();
> 1) .... | 0.335 us | __sb_end_write();
> 1) d... | 0.439 us | fpregs_assert_state_consistent();
> 1) d... | | do_syscall_64() {
> 1) .... | | __x64_sys_close() {
>
> Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
> ---
> tools/perf/builtin-ftrace.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> index d376b37c53fc..fd8e2f305136 100644
> --- a/tools/perf/builtin-ftrace.c
> +++ b/tools/perf/builtin-ftrace.c
> @@ -44,6 +44,7 @@ struct perf_ftrace {
> bool nosleep_time;
> bool nofuncgraph_irqs;
> bool funcgraph_tail;
> + bool latency_format;
> bool long_info;
> unsigned tracing_thresh;
> bool trace_children;
> @@ -217,6 +218,7 @@ static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
> write_tracing_option_file("sleep-time", "1");
> write_tracing_option_file("funcgraph-irqs", "1");
> write_tracing_option_file("funcgraph-tail", "0");
> + write_tracing_option_file("latency-format", "0");
> write_tracing_option_file("funcgraph-proc", "0");
> write_tracing_option_file("funcgraph-abstime", "0");
> write_tracing_option_file("irq-info", "0");
> @@ -456,6 +458,17 @@ static int set_tracing_funcgraph_tail(struct perf_ftrace *ftrace)
> return 0;
> }
>
> +static int set_tracing_latency_format(struct perf_ftrace *ftrace)
> +{
> + if (!ftrace->latency_format)
> + return 0;
> +
> + if (write_tracing_option_file("latency-format", "1") < 0)
> + return -1;
> +
> + return 0;
> +}
> +
> static int set_tracing_trace_children(struct perf_ftrace *ftrace)
> {
> if (!ftrace->trace_children)
> @@ -579,6 +592,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
> goto out_reset;
> }
>
> + if (set_tracing_latency_format(ftrace) < 0) {
> + pr_err("failed to set tracing option latency-format\n");
> + goto out_reset;
> + }
> +
> if (set_tracing_trace_children(ftrace) < 0) {
> pr_err("failed to set tracing option function-fork\n");
> goto out_reset;
> @@ -748,6 +766,8 @@ int cmd_ftrace(int argc, const char **argv)
> "Ignore functions that happen inside interrupt (function_graph only)"),
> OPT_BOOLEAN(0, "funcgraph-tail", &ftrace.funcgraph_tail,
> "Show function tails comment (function_graph only)"),
> + OPT_BOOLEAN(0, "latency-format", &ftrace.latency_format,
> + "displays additional information about the latency (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,
> --
> 2.25.1
>

--

- Arnaldo