[PATCH v4 11/17] perf ftrace: add support for trace option funcgraph-irqs

From: Changbin Du
Date: Fri Jul 10 2020 - 09:45:15 EST


This adds an option '--graph-opts noirqs' to filter out functions executed
in irq context.

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

---
v2: option name '--nofuncgraph-irqs' -> '--graph-noirqs'.
---
tools/perf/Documentation/perf-ftrace.txt | 1 +
tools/perf/builtin-ftrace.c | 21 ++++++++++++++++++++-
2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 760c2b78c305..2e16e1e588d9 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -105,6 +105,7 @@ OPTIONS
--graph-opts::
List of options allowed to set:
nosleep-time - Measure on-CPU time only for function_graph tracer.
+ noirqs - Ignore functions that happen inside interrupt.

SEE ALSO
--------
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index b4eda459ba78..179c5da678e3 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -43,6 +43,7 @@ struct perf_ftrace {
bool inherit;
int func_stack_trace;
int graph_nosleep_time;
+ int graph_noirqs;
};

struct filter_entry {
@@ -202,6 +203,7 @@ 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");
+ write_tracing_option_file("funcgraph-irqs", "1");
}

static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
@@ -394,6 +396,17 @@ static int set_tracing_sleep_time(struct perf_ftrace *ftrace)
return 0;
}

+static int set_tracing_funcgraph_irqs(struct perf_ftrace *ftrace)
+{
+ if (!ftrace->graph_noirqs)
+ return 0;
+
+ if (write_tracing_option_file("funcgraph-irqs", "0") < 0)
+ return -1;
+
+ return 0;
+}
+
static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
{
char *trace_file;
@@ -478,6 +491,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
goto out_reset;
}

+ if (set_tracing_funcgraph_irqs(ftrace) < 0) {
+ pr_err("failed to set tracing option funcgraph-irqs\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;
@@ -658,6 +676,7 @@ static int parse_graph_tracer_opts(const struct option *opt,
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 = "noirqs", .value_ptr = &ftrace->graph_noirqs },
{ .name = NULL, }
};

@@ -714,7 +733,7 @@ int cmd_ftrace(int argc, const char **argv)
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",
+ "graph tracer options, available options: nosleep-time,noirqs",
parse_graph_tracer_opts),
OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
"size of per cpu buffer", parse_buffer_size),
--
2.25.1