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perf ftrace: Add support for trace option sleep-time
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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 <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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changbindu authored and acmel committed Aug 14, 2020
1 parent b1d84af commit 38988f2
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4 changes: 4 additions & 0 deletions tools/perf/Documentation/perf-ftrace.txt
Original file line number Diff line number Diff line change
Expand Up @@ -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]
41 changes: 41 additions & 0 deletions tools/perf/builtin-ftrace.c
Original file line number Diff line number Diff line change
Expand Up @@ -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 {
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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) ||
Expand Down Expand Up @@ -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,
Expand Down

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