[PATCH v2 11/15] perf ftrace: add support for trace option funcgraph-irqs

From: Changbin Du
Date: Sat Jun 27 2020 - 09:38:36 EST


This adds an option '--graph-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 | 3 +++
tools/perf/builtin-ftrace.c | 20 ++++++++++++++++++++
2 files changed, 23 insertions(+)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index a3000436f80b..b616e05d5156 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -107,6 +107,9 @@ OPTIONS
--graph-nosleep-time::
Measure on-CPU time only for function_graph tracer.

+--graph-noirqs::
+ Ignore functions that happen inside interrupt 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 eba125a60820..876c8e800425 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -43,6 +43,7 @@ struct perf_ftrace {
bool inherit;
bool func_stack_trace;
bool graph_nosleep_time;
+ bool 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)
@@ -393,6 +395,17 @@ 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;
@@ -477,6 +490,11 @@ 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 +676,8 @@ int cmd_ftrace(int argc, const char **argv)
"trace children processes"),
OPT_BOOLEAN(0, "graph-nosleep-time", &ftrace.graph_nosleep_time,
"measure on-CPU time only for function_graph tracer"),
+ OPT_BOOLEAN(0, "graph-noirqs", &ftrace.graph_noirqs,
+ "ignore functions that happen inside interrupt for function_graph tracer"),
OPT_END()
};

--
2.25.1