perf ftrace: Add option '--inherit' to trace children processes (5b347472) · Commits · 戴 / test

tools/perf/Documentation/perf-ftrace.txt

+3 −0

Original line number	Diff line number	Diff line
		@@ -58,6 +58,9 @@ OPTIONS
		Set the size of per-cpu tracing buffer, <size> is expected to
		be a number with appended unit character - B/K/M/G.

		--inherit::
		Trace children processes spawned by our target.

		-T::
		--trace-funcs=::
		Select function tracer and set function filter on the given

tools/perf/builtin-ftrace.c

+38 −0

Original line number	Diff line number	Diff line
		@@ -41,6 +41,7 @@ struct perf_ftrace {
		struct list_head nograph_funcs;
		int graph_depth;
		unsigned long percpu_buffer_size;
		bool inherit;
		};

		struct filter_entry {
		@@ -182,9 +183,27 @@ static int write_tracing_file_int(const char *name, int value)
		return 0;
		}

		static int write_tracing_option_file(const char name, const char val)
		{
		char *file;
		int ret;

		if (asprintf(&file, "options/%s", name) < 0)
		return -1;

		ret = __write_tracing_file(file, val, false);
		free(file);
		return ret;
		}

		static int reset_tracing_cpu(void);
		static void reset_tracing_filters(void);

		static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
		{
		write_tracing_option_file("function-fork", "0");
		}

		static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
		{
		if (write_tracing_file("tracing_on", "0") < 0)
		@@ -203,6 +222,7 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
		return -1;

		reset_tracing_filters();
		reset_tracing_options(ftrace);
		return 0;
		}

		@@ -341,6 +361,17 @@ static int set_tracing_percpu_buffer_size(struct perf_ftrace *ftrace)
		return 0;
		}

		static int set_tracing_trace_inherit(struct perf_ftrace *ftrace)
		{
		if (!ftrace->inherit)
		return 0;

		if (write_tracing_option_file("function-fork", "1") < 0)
		return -1;

		return 0;
		}

		static int __cmd_ftrace(struct perf_ftrace ftrace, int argc, const char *argv)
		{
		char *trace_file;
		@@ -410,6 +441,11 @@ static int __cmd_ftrace(struct perf_ftrace ftrace, int argc, const char *argv)
		goto out_reset;
		}

		if (set_tracing_trace_inherit(ftrace) < 0) {
		pr_err("failed to set tracing option function-fork\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;
		@@ -618,6 +654,8 @@ int cmd_ftrace(int argc, const char **argv)
		"Max depth for function graph tracer"),
		OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
		"size of per cpu buffer", parse_buffer_size),
		OPT_BOOLEAN(0, "inherit", &ftrace.inherit,
		"trace children processes"),
		OPT_END()
		};

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