[PATCH v2 12/15] perf ftrace: add support for tracing option 'irq-info'

[Changbin Du <changbin.du@gmail.com>]

This adds support to display irq context info for function tracer. To do
this, just specify a '--func-irq-info' option.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 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 b616e05d5156..3c9eb044b7eb 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -84,6 +84,9 @@ OPTIONS
 --func-call-graph::
 	Display kernel stack trace for function tracer.
 
+--func-irq-info::
+	Display irq context info for function tracer.
+
 -G::
 --graph-funcs=::
 	Set graph filter on the given function (or a glob pattern).
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 876c8e800425..0a1e481b66a0 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -42,6 +42,7 @@ struct perf_ftrace {
 	unsigned		buffer_size_kb;
 	bool			inherit;
 	bool			func_stack_trace;
+	bool			func_irq_info;
 	bool			graph_nosleep_time;
 	bool			graph_noirqs;
 };
@@ -204,6 +205,7 @@ static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
 	write_tracing_option_file("func_stack_trace", "0");
 	write_tracing_option_file("sleep-time", "1");
 	write_tracing_option_file("funcgraph-irqs", "1");
+	write_tracing_option_file("irq-info", "0");
 }
 
 static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
@@ -291,6 +293,17 @@ static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace)
 	return 0;
 }
 
+static int set_tracing_func_irqinfo(struct perf_ftrace *ftrace)
+{
+	if (!ftrace->func_irq_info)
+		return 0;
+
+	if (write_tracing_option_file("irq-info", "1") < 0)
+		return -1;
+
+	return 0;
+}
+
 static int reset_tracing_cpu(void)
 {
 	struct perf_cpu_map *cpumap = perf_cpu_map__new(NULL);
@@ -465,6 +478,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 		goto out_reset;
 	}
 
+	if (set_tracing_func_irqinfo(ftrace) < 0) {
+		pr_err("failed to set tracing option irq-info\n");
+		goto out_reset;
+	}
+
 	if (set_tracing_filters(ftrace) < 0) {
 		pr_err("failed to set tracing filters\n");
 		goto out_reset;
@@ -661,6 +679,8 @@ int cmd_ftrace(int argc, const char **argv)
 		     "do not trace given functions", parse_filter_func),
 	OPT_BOOLEAN(0, "func-call-graph", &ftrace.func_stack_trace,
 		    "show kernel stack trace for function tracer"),
+	OPT_BOOLEAN(0, "func-irq-info", &ftrace.func_irq_info,
+		    "display irq info for function tracer"),
 	OPT_CALLBACK_DEFAULT('G', "graph-funcs", &ftrace.graph_funcs, "func",
 			     "trace given functions using function_graph tracer",
 			     parse_filter_func, "*"),
-- 
2.25.1