[PATCH v4 10/17] perf ftrace: add support for trace option sleep-time

From: Changbin Du
Date: Fri Jul 10 2020 - 09:45:13 EST


This adds an option '--graph-opts nosleep-time' which allow us
only to measure on-CPU time. This option is function_graph tracer
only.

Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>

---
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 676a30cb9b5a..760c2b78c305 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -102,6 +102,10 @@ 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 91611eef5deb..b4eda459ba78 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -42,6 +42,7 @@ struct perf_ftrace {
unsigned long percpu_buffer_size;
bool inherit;
int func_stack_trace;
+ int graph_nosleep_time;
};

struct filter_entry {
@@ -200,6 +201,7 @@ 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)
@@ -381,6 +383,17 @@ 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;
@@ -460,6 +473,11 @@ 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;
@@ -633,6 +651,26 @@ 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;
+}
+
int cmd_ftrace(int argc, const char **argv)
{
int ret;
@@ -675,6 +713,9 @@ 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