[PATCH v6 00/17] perf: ftrace enhancement

[PATCH v6 00/17] perf: ftrace enhancement

[Changbin Du]

The perf has basic kernel ftrace support but lack support of most tracing
options. This serias is target to enhance the perf ftrace functionality so
that we can make full use of kernel ftrace with perf.

In general, this serias be cataloged into two main changes:
  1) Improve usability of existing functions. For example, we don't need to type
     extra option to select the tracer.
  2) Add new options to support all other ftrace functions.

Here is a glance of all ftrace functions with this serias:

$ sudo perf ftrace -h

 Usage: perf ftrace [<options>] [<command>]
    or: perf ftrace [<options>] -- <command> [<options>]

    -a, --all-cpus        system-wide collection from all CPUs
    -C, --cpu <cpu>       list of cpus to monitor
    -D, --delay <n>       ms to wait before starting tracing after program start
    -F, --funcs           Show available functions to filter
    -G, --graph-funcs <func>
                          trace given functions using function_graph tracer
    -g, --nograph-funcs <func>
                          Set nograph filter on given functions
    -m, --buffer-size <size>
                          size of per cpu buffer
    -N, --notrace-funcs <func>
                          do not trace given functions
    -p, --pid <pid>       trace on existing process id
    -T, --trace-funcs <func>
                          trace given functions using function tracer
    -t, --tracer <tracer>
                          tracer to use: function or function_graph (This option is deprecated)
    -v, --verbose         be more verbose
        --func-opts <options>
                          function tracer options, available options: call-graph,irq-info
        --graph-opts <options>
                          graph tracer options, available options: nosleep-time,noirqs,verbose,thresh=<n>,depth=<n>
        --inherit         trace children processes

v6:
  o fix return value of read_tracing_file_to_stdout().
  o make __cmd_ftrace() shorter.
  o remove option '-t, --tid <tid>'.
v5:
  o trivial fixes.
v4:
  o add util/parse-sublevel-options.c
  O remove -D/--graph-depth
v3:
  o add --func-opts and --graph-opts to set tracer specific options.
  o support units as a suffix for option '-m/--buffer-size'.
v2:
  o patches for option '-u/--userstacktrace' and '--no-pager' are dropped.
  o update all related perf documentation.
  o rename some options. Now all funcgraph tracer options are prefixed with
    '--graph-', while all function tracer options are prefixed with '--func-'.
  o mark old options deprecated instead of removing them.


Changbin Du (17):
  perf ftrace: select function/function_graph tracer automatically
  perf ftrace: add option '-F/--funcs' to list available functions
  perf ftrace: factor out function write_tracing_file_int()
  perf ftrace: add option '-m/--buffer-size' to set per-cpu buffer size
  perf ftrace: show trace column header
  perf ftrace: add option '--inherit' to trace children processes
  perf: util: add general function to parse sublevel options
  perf ftrace: add support for tracing option 'func_stack_trace'
  perf ftrace: add support for trace option sleep-time
  perf ftrace: add support for trace option funcgraph-irqs
  perf ftrace: add support for tracing option 'irq-info'
  perf ftrace: add option 'verbose' to show more info for graph tracer
  perf ftrace: add support for trace option tracing_thresh
  perf: ftrace: allow set graph depth by '--graph-opts'
  perf ftrace: add option -D/--delay to delay tracing
  perf: ftrace: Add set_tracing_options() to set all trace options
  perf ftrace: add change log

 tools/perf/Documentation/perf-config.txt |   5 -
 tools/perf/Documentation/perf-ftrace.txt |  33 +-
 tools/perf/builtin-ftrace.c              | 412 +++++++++++++++++++++--
 tools/perf/util/Build                    |   1 +
 tools/perf/util/debug.c                  |  61 +---
 tools/perf/util/parse-sublevel-options.c |  70 ++++
 tools/perf/util/parse-sublevel-options.h |  11 +
 7 files changed, 507 insertions(+), 86 deletions(-)
 create mode 100644 tools/perf/util/parse-sublevel-options.c
 create mode 100644 tools/perf/util/parse-sublevel-options.h

-- 
2.25.1

[PATCH v6 01/17] perf ftrace: select function/function_graph tracer automatically

[Changbin Du]

The '-g/-G' options have already implied function_graph tracer should be
used instead of function tracer. So the extra option '--tracer' can be
killed.

This patch changes the behavior as below:
  - By default, function tracer is used.
  - If '-g' or '-G' option is on, then function_graph tracer is used.
  - The perf configuration item 'ftrace.tracer' is marked as deprecated.
  - The option '--tracer' is marked as deprecated.

Here are some examples.

This will start tracing all functions using function tracer:
  $ sudo perf ftrace

This will trace all functions using function graph tracer:
  $ sudo perf ftrace -G '*'

This will trace function vfs_read using function graph tracer:
  $ sudo perf ftrace -G vfs_read

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

---
v3: remove default '*' for -G/-T.
---
 tools/perf/Documentation/perf-config.txt |  5 -----
 tools/perf/Documentation/perf-ftrace.txt |  2 +-
 tools/perf/builtin-ftrace.c              | 15 ++++++++++-----
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
index c7d3df5798e2..a25fee7de3b2 100644
--- a/tools/perf/Documentation/perf-config.txt
+++ b/tools/perf/Documentation/perf-config.txt
@@ -612,11 +612,6 @@ trace.*::
 		"libbeauty", the default, to use the same argument beautifiers used in the
 		strace-like sys_enter+sys_exit lines.
 
-ftrace.*::
-	ftrace.tracer::
-		Can be used to select the default tracer. Possible values are
-		'function' and 'function_graph'.
-
 llvm.*::
 	llvm.clang-path::
 		Path to clang. If omit, search it from $PATH.
diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index b80c84307dc9..952e46669168 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -24,7 +24,7 @@ OPTIONS
 
 -t::
 --tracer=::
-	Tracer to use: function_graph or function.
+	Tracer to use: function_graph or function. This option is deprecated.
 
 -v::
 --verbose=::
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 2bfc1b0db536..5f53da87040d 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -27,7 +27,6 @@
 #include "util/cap.h"
 #include "util/config.h"
 
-#define DEFAULT_TRACER  "function_graph"
 
 struct perf_ftrace {
 	struct evlist		*evlist;
@@ -419,6 +418,7 @@ static int perf_ftrace_config(const char *var, const char *value, void *cb)
 	if (strcmp(var, "ftrace.tracer"))
 		return -1;
 
+	pr_warning("Configuration ftrace.tracer is deprecated\n");
 	if (!strcmp(value, "function_graph") ||
 	    !strcmp(value, "function")) {
 		ftrace->tracer = value;
@@ -459,7 +459,7 @@ int cmd_ftrace(int argc, const char **argv)
 {
 	int ret;
 	struct perf_ftrace ftrace = {
-		.tracer = DEFAULT_TRACER,
+		.tracer = "function",
 		.target = { .uid = UINT_MAX, },
 	};
 	const char * const ftrace_usage[] = {
@@ -469,7 +469,7 @@ int cmd_ftrace(int argc, const char **argv)
 	};
 	const struct option ftrace_options[] = {
 	OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
-		   "tracer to use: function_graph(default) or function"),
+		   "tracer to use: function or function_graph (This option is deprecated)"),
 	OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
 		   "trace on existing process id"),
 	OPT_INCR('v', "verbose", &verbose,
@@ -479,11 +479,13 @@ int cmd_ftrace(int argc, const char **argv)
 	OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
 		    "list of cpus to monitor"),
 	OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
-		     "trace given functions only", parse_filter_func),
+		     "trace given functions using function tracer",
+		     parse_filter_func),
 	OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
 		     "do not trace given functions", parse_filter_func),
 	OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
-		     "Set graph filter on given functions", parse_filter_func),
+		     "trace given functions using function_graph tracer",
+		     parse_filter_func),
 	OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
 		     "Set nograph filter on given functions", parse_filter_func),
 	OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth,
@@ -505,6 +507,9 @@ int cmd_ftrace(int argc, const char **argv)
 	if (!argc && target__none(&ftrace.target))
 		ftrace.target.system_wide = true;
 
+	if (!list_empty(&ftrace.graph_funcs) || !list_empty(&ftrace.nograph_funcs))
+		ftrace.tracer = "function_graph";
+
 	ret = target__validate(&ftrace.target);
 	if (ret) {
 		char errbuf[512];
-- 
2.25.1

[PATCH v6 02/17] perf ftrace: add option '-F/--funcs' to list available functions

[Changbin Du]

This adds an option '-F/--funcs' to list all available functions to trace,
which is read from tracing file 'available_filter_functions'.

$ sudo ./perf ftrace -F | head
trace_initcall_finish_cb
initcall_blacklisted
do_one_initcall
do_one_initcall
trace_initcall_start_cb
run_init_process
try_to_run_init_process
match_dev_by_label
match_dev_by_uuid
rootfs_init_fs_context

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

---
v3: fix return value issue.
v2: option name '-l/--list-functions' -> '-F/--funcs'
---
 tools/perf/Documentation/perf-ftrace.txt |  4 +++
 tools/perf/builtin-ftrace.c              | 46 ++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 952e46669168..d79560dea19f 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -30,6 +30,10 @@ OPTIONS
 --verbose=::
         Verbosity level.
 
+-F::
+--funcs::
+        List all available functions to trace.
+
 -p::
 --pid=::
 	Trace on existing process id (comma separated list).
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 5f53da87040d..3c0e60fdfe0f 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -32,6 +32,7 @@ struct perf_ftrace {
 	struct evlist		*evlist;
 	struct target		target;
 	const char		*tracer;
+	bool			list_avail_functions;
 	struct list_head	filters;
 	struct list_head	notrace;
 	struct list_head	graph_funcs;
@@ -127,6 +128,46 @@ static int append_tracing_file(const char *name, const char *val)
 	return __write_tracing_file(name, val, true);
 }
 
+static int read_tracing_file_to_stdout(const char *name)
+{
+	char buf[4096];
+	char *file;
+	int fd;
+	int ret = -1;
+
+	file = get_tracing_file(name);
+	if (!file) {
+		pr_debug("cannot get tracing file: %s\n", name);
+		return -1;
+	}
+
+	fd = open(file, O_RDONLY);
+	if (fd < 0) {
+		pr_debug("cannot open tracing file: %s: %s\n",
+			 name, str_error_r(errno, buf, sizeof(buf)));
+		goto out;
+	}
+
+	/* read contents to stdout */
+	while (true) {
+		int n = read(fd, buf, sizeof(buf));
+		if (n == 0)
+			break;
+		else if (n < 0)
+			goto out_close;
+
+		if (fwrite(buf, n, 1, stdout) != 1)
+			goto out_close;
+	}
+	ret = 0;
+
+out_close:
+	close(fd);
+out:
+	put_tracing_file(file);
+	return ret;
+}
+
 static int reset_tracing_cpu(void);
 static void reset_tracing_filters(void);
 
@@ -301,6 +342,9 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 	signal(SIGCHLD, sig_handler);
 	signal(SIGPIPE, sig_handler);
 
+	if (ftrace->list_avail_functions)
+		return read_tracing_file_to_stdout("available_filter_functions");
+
 	if (reset_tracing_files(ftrace) < 0) {
 		pr_err("failed to reset ftrace\n");
 		goto out;
@@ -470,6 +514,8 @@ int cmd_ftrace(int argc, const char **argv)
 	const struct option ftrace_options[] = {
 	OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
 		   "tracer to use: function or function_graph (This option is deprecated)"),
+	OPT_BOOLEAN('F', "funcs", &ftrace.list_avail_functions,
+		    "Show available functions to filter"),
 	OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
 		   "trace on existing process id"),
 	OPT_INCR('v', "verbose", &verbose,
-- 
2.25.1

[PATCH v6 03/17] perf ftrace: factor out function write_tracing_file_int()

[Changbin Du]

We will reuse this function later.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 tools/perf/builtin-ftrace.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 3c0e60fdfe0f..9abf97c29cb6 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -168,6 +168,17 @@ static int read_tracing_file_to_stdout(const char *name)
 	return ret;
 }
 
+static int write_tracing_file_int(const char *name, int value)
+{
+	char buf[16];
+
+	snprintf(buf, sizeof(buf), "%d", value);
+	if (write_tracing_file(name, buf) < 0)
+		return -1;
+
+	return 0;
+}
+
 static int reset_tracing_cpu(void);
 static void reset_tracing_filters(void);
 
@@ -298,8 +309,6 @@ static void reset_tracing_filters(void)
 
 static int set_tracing_depth(struct perf_ftrace *ftrace)
 {
-	char buf[16];
-
 	if (ftrace->graph_depth == 0)
 		return 0;
 
@@ -308,9 +317,7 @@ static int set_tracing_depth(struct perf_ftrace *ftrace)
 		return -1;
 	}
 
-	snprintf(buf, sizeof(buf), "%d", ftrace->graph_depth);
-
-	if (write_tracing_file("max_graph_depth", buf) < 0)
+	if (write_tracing_file_int("max_graph_depth", ftrace->graph_depth) < 0)
 		return -1;
 
 	return 0;
-- 
2.25.1

[PATCH v6 04/17] perf ftrace: add option '-m/--buffer-size' to set per-cpu buffer size

[Changbin Du]

This adds an option '-m/--buffer-size' to allow us set the size of per-cpu
tracing buffer.

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

---
v2: support units as a suffix.
---
 tools/perf/Documentation/perf-ftrace.txt |  5 +++
 tools/perf/builtin-ftrace.c              | 56 +++++++++++++++++++++++-
 2 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index d79560dea19f..dcac0d75a0e5 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -52,6 +52,11 @@ OPTIONS
 	Ranges of CPUs are specified with -: 0-2.
 	Default is to trace on all online CPUs.
 
+-m::
+--buffer-size::
+	Set the size of per-cpu tracing buffer, <size> is expected to
+	be a number with appended unit character - B/K/M/G.
+
 -T::
 --trace-funcs=::
 	Only trace functions given by the argument.  Multiple functions
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 9abf97c29cb6..3ea3aaa4650b 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -26,7 +26,7 @@
 #include "thread_map.h"
 #include "util/cap.h"
 #include "util/config.h"
-
+#include "util/units.h"
 
 struct perf_ftrace {
 	struct evlist		*evlist;
@@ -38,6 +38,7 @@ struct perf_ftrace {
 	struct list_head	graph_funcs;
 	struct list_head	nograph_funcs;
 	int			graph_depth;
+	unsigned long		percpu_buffer_size;
 };
 
 struct filter_entry {
@@ -323,6 +324,21 @@ static int set_tracing_depth(struct perf_ftrace *ftrace)
 	return 0;
 }
 
+static int set_tracing_percpu_buffer_size(struct perf_ftrace *ftrace)
+{
+	int ret;
+
+	if (ftrace->percpu_buffer_size == 0)
+		return 0;
+
+	ret = write_tracing_file_int("buffer_size_kb",
+				     ftrace->percpu_buffer_size / 1024);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
 static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
 	char *trace_file;
@@ -387,6 +403,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 		goto out_reset;
 	}
 
+	if (set_tracing_percpu_buffer_size(ftrace) < 0) {
+		pr_err("failed to set tracing per-cpu buffer size\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;
@@ -506,6 +527,37 @@ static void delete_filter_func(struct list_head *head)
 	}
 }
 
+static int parse_buffer_size(const struct option *opt,
+			     const char *str, int unset)
+{
+	unsigned long *s = (unsigned long *)opt->value;
+	static struct parse_tag tags_size[] = {
+		{ .tag  = 'B', .mult = 1       },
+		{ .tag  = 'K', .mult = 1 << 10 },
+		{ .tag  = 'M', .mult = 1 << 20 },
+		{ .tag  = 'G', .mult = 1 << 30 },
+		{ .tag  = 0 },
+	};
+	unsigned long val;
+
+	if (unset) {
+		*s = 0;
+		return 0;
+	}
+
+	val = parse_tag_value(str, tags_size);
+	if (val != (unsigned long) -1) {
+		if (val < 1024) {
+			pr_err("buffer size too small, must larger than 1KB.");
+			return -1;
+		}
+		*s = val;
+		return 0;
+	}
+
+	return -1;
+}
+
 int cmd_ftrace(int argc, const char **argv)
 {
 	int ret;
@@ -543,6 +595,8 @@ 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('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
+		     "size of per cpu buffer", parse_buffer_size),
 	OPT_END()
 	};
 
-- 
2.25.1

[PATCH v6 05/17] perf ftrace: show trace column header

[Changbin Du]

This makes perf-ftrace display column header before printing trace.

  $ sudo perf ftrace
  # tracer: function
  #
  # entries-in-buffer/entries-written: 0/0   #P:8
  #
  #            TASK-PID     CPU#   TIMESTAMP  FUNCTION
  #              | |         |       |         |
             <...>-9246  [006]  10726.262760: mutex_unlock <-rb_simple_write
             <...>-9246  [006]  10726.262764: __fsnotify_parent <-vfs_write
             <...>-9246  [006]  10726.262765: fsnotify <-vfs_write
             <...>-9246  [006]  10726.262766: __sb_end_write <-vfs_write
             <...>-9246  [006]  10726.262767: fpregs_assert_state_consistent <-do_syscall_64

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 tools/perf/builtin-ftrace.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 3ea3aaa4650b..6ce626a2d0d1 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -433,6 +433,9 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 	fcntl(trace_fd, F_SETFL, O_NONBLOCK);
 	pollfd.fd = trace_fd;
 
+	/* display column headers */
+	read_tracing_file_to_stdout("trace");
+
 	if (write_tracing_file("tracing_on", "1") < 0) {
 		pr_err("can't enable tracing\n");
 		goto out_close_fd;
-- 
2.25.1

[PATCH v6 06/17] perf ftrace: add option '--inherit' to trace children processes

[Changbin Du]

This adds an option '--inherit' to allow us trace children
processes spawned by our target.

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

---
v2: option name '--trace-children' -> '--inherit'.
---
 tools/perf/Documentation/perf-ftrace.txt |  3 ++
 tools/perf/builtin-ftrace.c              | 38 ++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index dcac0d75a0e5..3eee073a7042 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -57,6 +57,9 @@ 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=::
 	Only trace functions given by the argument.  Multiple functions
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 6ce626a2d0d1..765ebd56e05f 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -39,6 +39,7 @@ struct perf_ftrace {
 	struct list_head	nograph_funcs;
 	int			graph_depth;
 	unsigned long		percpu_buffer_size;
+	bool			inherit;
 };
 
 struct filter_entry {
@@ -180,9 +181,27 @@ 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)
@@ -201,6 +220,7 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
 		return -1;
 
 	reset_tracing_filters();
+	reset_tracing_options(ftrace);
 	return 0;
 }
 
@@ -339,6 +359,17 @@ 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;
@@ -408,6 +439,11 @@ 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;
@@ -600,6 +636,8 @@ 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()
 	};
 
-- 
2.25.1

[PATCH v6 07/17] perf: util: add general function to parse sublevel options

[Changbin Du]

This factors out a general function perf_parse_sublevel_options() to parse
sublevel options. The 'sublevel' options is something like the '--debug'
options which allow more sublevel options.

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

---
v2: add util/parse-sublevel-options.c
---
 tools/perf/util/Build                    |  1 +
 tools/perf/util/debug.c                  | 61 ++++++---------------
 tools/perf/util/parse-sublevel-options.c | 70 ++++++++++++++++++++++++
 tools/perf/util/parse-sublevel-options.h | 11 ++++
 4 files changed, 99 insertions(+), 44 deletions(-)
 create mode 100644 tools/perf/util/parse-sublevel-options.c
 create mode 100644 tools/perf/util/parse-sublevel-options.h

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 8d18380ecd10..e86607ada0b5 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -117,6 +117,7 @@ endif
 perf-y += parse-branch-options.o
 perf-y += dump-insn.o
 perf-y += parse-regs-options.o
+perf-y += parse-sublevel-options.o
 perf-y += term.o
 perf-y += help-unknown-cmd.o
 perf-y += mem-events.o
diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index adb656745ecc..5cda5565777a 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -20,6 +20,7 @@
 #include "target.h"
 #include "ui/helpline.h"
 #include "ui/ui.h"
+#include "util/parse-sublevel-options.h"
 
 #include <linux/ctype.h>
 
@@ -173,65 +174,37 @@ void trace_event(union perf_event *event)
 		     trace_event_printer, event);
 }
 
-static struct debug_variable {
-	const char *name;
-	int *ptr;
-} debug_variables[] = {
-	{ .name = "verbose",		.ptr = &verbose },
-	{ .name = "ordered-events",	.ptr = &debug_ordered_events},
-	{ .name = "stderr",		.ptr = &redirect_to_stderr},
-	{ .name = "data-convert",	.ptr = &debug_data_convert },
-	{ .name = "perf-event-open",	.ptr = &debug_peo_args },
+static struct sublevel_option debug_opts[] = {
+	{ .name = "verbose",		.value_ptr = &verbose },
+	{ .name = "ordered-events",	.value_ptr = &debug_ordered_events},
+	{ .name = "stderr",		.value_ptr = &redirect_to_stderr},
+	{ .name = "data-convert",	.value_ptr = &debug_data_convert },
+	{ .name = "perf-event-open",	.value_ptr = &debug_peo_args },
 	{ .name = NULL, }
 };
 
 int perf_debug_option(const char *str)
 {
-	struct debug_variable *var = &debug_variables[0];
-	char *vstr, *s = strdup(str);
-	int v = 1;
-
-	vstr = strchr(s, '=');
-	if (vstr)
-		*vstr++ = 0;
-
-	while (var->name) {
-		if (!strcmp(s, var->name))
-			break;
-		var++;
-	}
-
-	if (!var->name) {
-		pr_err("Unknown debug variable name '%s'\n", s);
-		free(s);
-		return -1;
-	}
+	int ret;
 
-	if (vstr) {
-		v = atoi(vstr);
-		/*
-		 * Allow only values in range (0, 10),
-		 * otherwise set 0.
-		 */
-		v = (v < 0) || (v > 10) ? 0 : v;
-	}
+	ret = perf_parse_sublevel_options(str, debug_opts);
+	if (ret)
+		return ret;
 
-	if (quiet)
-		v = -1;
+	/* Allow only verbose value in range (0, 10), otherwise set 0. */
+	verbose = (verbose < 0) || (verbose > 10) ? 0 : verbose;
 
-	*var->ptr = v;
-	free(s);
 	return 0;
 }
 
 int perf_quiet_option(void)
 {
-	struct debug_variable *var = &debug_variables[0];
+	struct sublevel_option *opt = &debug_opts[0];
 
 	/* disable all debug messages */
-	while (var->name) {
-		*var->ptr = -1;
-		var++;
+	while (opt->name) {
+		*opt->value_ptr = -1;
+		opt++;
 	}
 
 	return 0;
diff --git a/tools/perf/util/parse-sublevel-options.c b/tools/perf/util/parse-sublevel-options.c
new file mode 100644
index 000000000000..a841d17ffd57
--- /dev/null
+++ b/tools/perf/util/parse-sublevel-options.c
@@ -0,0 +1,70 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "util/debug.h"
+#include "util/parse-sublevel-options.h"
+
+static int parse_one_sublevel_option(const char *str,
+				     struct sublevel_option *opts)
+{
+	struct sublevel_option *opt = opts;
+	char *vstr, *s = strdup(str);
+	int v = 1;
+
+	if (!s) {
+		pr_err("no memory\n");
+		return -1;
+	}
+
+	vstr = strchr(s, '=');
+	if (vstr)
+		*vstr++ = 0;
+
+	while (opt->name) {
+		if (!strcmp(s, opt->name))
+			break;
+		opt++;
+	}
+
+	if (!opt->name) {
+		pr_err("Unknown option name '%s'\n", s);
+		free(s);
+		return -1;
+	}
+
+	if (vstr)
+		v = atoi(vstr);
+
+	*opt->value_ptr = v;
+	free(s);
+	return 0;
+}
+
+/* parse options like --foo a=<n>,b,c... */
+int perf_parse_sublevel_options(const char *str, struct sublevel_option *opts)
+{
+	char *s = strdup(str);
+	char *p = NULL;
+	int ret;
+
+	if (!s) {
+		pr_err("no memory\n");
+		return -1;
+	}
+
+	p = strtok(s, ",");
+	while (p) {
+		ret = parse_one_sublevel_option(p, opts);
+		if (ret) {
+			free(s);
+			return ret;
+		}
+
+		p = strtok(NULL, ",");
+	}
+
+	free(s);
+	return 0;
+}
diff --git a/tools/perf/util/parse-sublevel-options.h b/tools/perf/util/parse-sublevel-options.h
new file mode 100644
index 000000000000..9b9efcc2aaad
--- /dev/null
+++ b/tools/perf/util/parse-sublevel-options.h
@@ -0,0 +1,11 @@
+#ifndef _PERF_PARSE_SUBLEVEL_OPTIONS_H
+#define _PERF_PARSE_SUBLEVEL_OPTIONS_H
+
+struct sublevel_option {
+	const char *name;
+	int *value_ptr;
+};
+
+int perf_parse_sublevel_options(const char *str, struct sublevel_option *opts);
+
+#endif
\ No newline at end of file
-- 
2.25.1

[PATCH v6 08/17] perf ftrace: add support for tracing option 'func_stack_trace'

[Changbin Du]

This adds support to display call trace for function tracer. To do this,
just specify a '--func-opts call-graph' option.

$ sudo perf ftrace -T vfs_read --func-opts call-graph
 iio-sensor-prox-855   [003]   6168.369657: vfs_read <-ksys_read
 iio-sensor-prox-855   [003]   6168.369677: <stack trace>
 => vfs_read
 => ksys_read
 => __x64_sys_read
 => do_syscall_64
 => entry_SYSCALL_64_after_hwframe
 ...

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

---
v3: switch to uniform option --func-opts.
v2: option name '-s' -> '--func-call-graph'
---
 tools/perf/Documentation/perf-ftrace.txt |  4 +++
 tools/perf/builtin-ftrace.c              | 42 ++++++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 3eee073a7042..5a5069306141 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -74,6 +74,10 @@ OPTIONS
 	(or glob patterns).  It will be passed to 'set_ftrace_notrace'
 	in tracefs.
 
+--func-opts::
+	List of options allowed to set:
+	  call-graph - Display kernel stack trace 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 765ebd56e05f..e7c8697294f0 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -27,6 +27,7 @@
 #include "util/cap.h"
 #include "util/config.h"
 #include "util/units.h"
+#include "util/parse-sublevel-options.h"
 
 struct perf_ftrace {
 	struct evlist		*evlist;
@@ -40,6 +41,7 @@ struct perf_ftrace {
 	int			graph_depth;
 	unsigned long		percpu_buffer_size;
 	bool			inherit;
+	int			func_stack_trace;
 };
 
 struct filter_entry {
@@ -200,6 +202,7 @@ static void reset_tracing_filters(void);
 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");
 }
 
 static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
@@ -276,6 +279,17 @@ static int set_tracing_cpu(struct perf_ftrace *ftrace)
 	return set_tracing_cpumask(cpumap);
 }
 
+static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace)
+{
+	if (!ftrace->func_stack_trace)
+		return 0;
+
+	if (write_tracing_option_file("func_stack_trace", "1") < 0)
+		return -1;
+
+	return 0;
+}
+
 static int reset_tracing_cpu(void)
 {
 	struct perf_cpu_map *cpumap = perf_cpu_map__new(NULL);
@@ -424,6 +438,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 		goto out_reset;
 	}
 
+	if (set_tracing_func_stack_trace(ftrace) < 0) {
+		pr_err("failed to set tracing option func_stack_trace\n");
+		goto out_reset;
+	}
+
 	if (set_tracing_filters(ftrace) < 0) {
 		pr_err("failed to set tracing filters\n");
 		goto out_reset;
@@ -597,6 +616,26 @@ static int parse_buffer_size(const struct option *opt,
 	return -1;
 }
 
+static int parse_func_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 func_tracer_opts[] = {
+		{ .name = "call-graph",	.value_ptr = &ftrace->func_stack_trace },
+		{ .name = NULL, }
+	};
+
+	if (unset)
+		return 0;
+
+	ret = perf_parse_sublevel_options(str, func_tracer_opts);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 int cmd_ftrace(int argc, const char **argv)
 {
 	int ret;
@@ -627,6 +666,9 @@ int cmd_ftrace(int argc, const char **argv)
 		     parse_filter_func),
 	OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
 		     "do not trace given functions", parse_filter_func),
+	OPT_CALLBACK(0, "func-opts", &ftrace, "options",
+		     "function tracer options, available options: call-graph",
+		     parse_func_tracer_opts),
 	OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
 		     "trace given functions using function_graph tracer",
 		     parse_filter_func),
-- 
2.25.1

[PATCH v6 09/17] perf ftrace: add support for trace option sleep-time

[Changbin Du]

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 <changbin.du@gmail.com>

---
v3: switch to uniform option --graph-opts.
v2: option name '--nosleep-time' -> '--graph-nosleep-time'.
---
 tools/perf/Documentation/perf-ftrace.txt |  4 +++
 tools/perf/builtin-ftrace.c              | 41 ++++++++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 5a5069306141..2968a34239a4 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -98,6 +98,10 @@ 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]
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index e7c8697294f0..835f810985f0 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -42,6 +42,7 @@ struct perf_ftrace {
 	unsigned long		percpu_buffer_size;
 	bool			inherit;
 	int			func_stack_trace;
+	int			graph_nosleep_time;
 };
 
 struct filter_entry {
@@ -203,6 +204,7 @@ 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)
@@ -384,6 +386,17 @@ 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;
@@ -463,6 +476,11 @@ 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;
@@ -636,6 +654,26 @@ 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;
+}
+
 int cmd_ftrace(int argc, const char **argv)
 {
 	int ret;
@@ -676,6 +714,9 @@ 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,
-- 
2.25.1

[PATCH v6 10/17] perf ftrace: add support for trace option funcgraph-irqs

[Changbin Du]

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

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

---
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 2968a34239a4..21d3b444587a 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -101,6 +101,7 @@ 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 835f810985f0..6402df3984c0 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 {
@@ -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");
+	write_tracing_option_file("funcgraph-irqs", "1");
 }
 
 static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
@@ -397,6 +399,17 @@ 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;
@@ -481,6 +494,11 @@ 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;
@@ -661,6 +679,7 @@ 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, }
 	};
 
@@ -715,7 +734,7 @@ 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

[PATCH v6 11/17] perf ftrace: add support for tracing option 'irq-info'

[Changbin Du]

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

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 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 21d3b444587a..3ab1fe040994 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -77,6 +77,7 @@ OPTIONS
 --func-opts::
 	List of options allowed to set:
 	  call-graph - Display kernel stack trace for function tracer.
+	  irq-info   - Display irq context info for function tracer.
 
 -G::
 --graph-funcs=::
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 6402df3984c0..95d87c5966ad 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -42,6 +42,7 @@ struct perf_ftrace {
 	unsigned long		percpu_buffer_size;
 	bool			inherit;
 	int			func_stack_trace;
+	int			func_irq_info;
 	int			graph_nosleep_time;
 	int			graph_noirqs;
 };
@@ -207,6 +208,7 @@ 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)
@@ -294,6 +296,17 @@ 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);
@@ -469,6 +482,11 @@ 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;
@@ -659,6 +677,7 @@ static int parse_func_tracer_opts(const struct option *opt,
 	struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
 	struct sublevel_option func_tracer_opts[] = {
 		{ .name = "call-graph",	.value_ptr = &ftrace->func_stack_trace },
+		{ .name = "irq-info",	.value_ptr = &ftrace->func_irq_info },
 		{ .name = NULL, }
 	};
 
@@ -724,7 +743,7 @@ int cmd_ftrace(int argc, const char **argv)
 	OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
 		     "do not trace given functions", parse_filter_func),
 	OPT_CALLBACK(0, "func-opts", &ftrace, "options",
-		     "function tracer options, available options: call-graph",
+		     "function tracer options, available options: call-graph,irq-info",
 		     parse_func_tracer_opts),
 	OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
 		     "trace given functions using function_graph tracer",
-- 
2.25.1

[PATCH v6 12/17] perf ftrace: add option 'verbose' to show more info for graph tracer

[Changbin Du]

Sometimes we want ftrace display more and longer information about
the trace.

$ sudo perf ftrace -G '*'
 2)   0.979 us    |  mutex_unlock();
 2)   1.540 us    |  __fsnotify_parent();
 2)   0.433 us    |  fsnotify();

$ sudo perf ftrace -G '*' --graph-opts verbose
14160.770883 |   0)  <...>-47814   |  .... |   1.289 us    |  mutex_unlock();
14160.770886 |   0)  <...>-47814   |  .... |   1.624 us    |  __fsnotify_parent();
14160.770887 |   0)  <...>-47814   |  .... |   0.636 us    |  fsnotify();
14160.770888 |   0)  <...>-47814   |  .... |   0.328 us    |  __sb_end_write();
14160.770888 |   0)  <...>-47814   |  d... |   0.430 us    |  fpregs_assert_state_consistent();
14160.770889 |   0)  <...>-47814   |  d... |               |  do_syscall_64() {
14160.770889 |   0)  <...>-47814   |  .... |               |    __x64_sys_close() {

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 tools/perf/Documentation/perf-ftrace.txt |  1 +
 tools/perf/builtin-ftrace.c              | 29 +++++++++++++++++++++++-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 3ab1fe040994..319ec6375228 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -103,6 +103,7 @@ OPTIONS
 	List of options allowed to set:
 	  nosleep-time - Measure on-CPU time only for function_graph tracer.
 	  noirqs       - Ignore functions that happen inside interrupt.
+	  verbose      - Show process names, PIDs, timestamps, etc.
 
 SEE ALSO
 --------
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 95d87c5966ad..0d893d97691d 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -45,6 +45,7 @@ struct perf_ftrace {
 	int			func_irq_info;
 	int			graph_nosleep_time;
 	int			graph_noirqs;
+	int			graph_verbose;
 };
 
 struct filter_entry {
@@ -208,6 +209,9 @@ 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("funcgraph-proc", "0");
+	write_tracing_option_file("funcgraph-abstime", "0");
+	write_tracing_option_file("latency-format", "0");
 	write_tracing_option_file("irq-info", "0");
 }
 
@@ -423,6 +427,23 @@ static int set_tracing_funcgraph_irqs(struct perf_ftrace *ftrace)
 	return 0;
 }
 
+static int set_tracing_funcgraph_verbose(struct perf_ftrace *ftrace)
+{
+	if (!ftrace->graph_verbose)
+		return 0;
+
+	if (write_tracing_option_file("funcgraph-proc", "1") < 0)
+		return -1;
+
+	if (write_tracing_option_file("funcgraph-abstime", "1") < 0)
+		return -1;
+
+	if (write_tracing_option_file("latency-format", "1") < 0)
+		return -1;
+
+	return 0;
+}
+
 static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
 	char *trace_file;
@@ -517,6 +538,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 		goto out_reset;
 	}
 
+	if (set_tracing_funcgraph_verbose(ftrace) < 0) {
+		pr_err("failed to set tracing option funcgraph-proc/funcgraph-abstime\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;
@@ -699,6 +725,7 @@ static int parse_graph_tracer_opts(const struct option *opt,
 	struct sublevel_option graph_tracer_opts[] = {
 		{ .name = "nosleep-time",	.value_ptr = &ftrace->graph_nosleep_time },
 		{ .name = "noirqs",		.value_ptr = &ftrace->graph_noirqs },
+		{ .name = "verbose",		.value_ptr = &ftrace->graph_verbose },
 		{ .name = NULL, }
 	};
 
@@ -753,7 +780,7 @@ 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,noirqs",
+		     "graph tracer options, available options: nosleep-time,noirqs,verbose",
 		     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

[PATCH v6 13/17] perf ftrace: add support for trace option tracing_thresh

[Changbin Du]

This adds an option '--graph-opts thresh' to setup trace duration
threshold for funcgraph tracer.

$ sudo ./perf ftrace -G '*' --graph-opts thresh=100
 3) ! 184.060 us  |    } /* schedule */
 3) ! 185.600 us  |  } /* exit_to_usermode_loop */
 2) ! 225.989 us  |    } /* schedule_idle */
 2) # 4140.051 us |  } /* do_idle */

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 tools/perf/Documentation/perf-ftrace.txt |  1 +
 tools/perf/builtin-ftrace.c              | 26 +++++++++++++++++++++++-
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 319ec6375228..96e5e8d7f65c 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -104,6 +104,7 @@ OPTIONS
 	  nosleep-time - Measure on-CPU time only for function_graph tracer.
 	  noirqs       - Ignore functions that happen inside interrupt.
 	  verbose      - Show process names, PIDs, timestamps, etc.
+	  thresh=<n>   - Setup trace duration threshold in microseconds.
 
 SEE ALSO
 --------
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 0d893d97691d..5d948239bd70 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -46,6 +46,7 @@ struct perf_ftrace {
 	int			graph_nosleep_time;
 	int			graph_noirqs;
 	int			graph_verbose;
+	int			graph_thresh;
 };
 
 struct filter_entry {
@@ -232,6 +233,9 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
 	if (write_tracing_file("max_graph_depth", "0") < 0)
 		return -1;
 
+	if (write_tracing_file("tracing_thresh", "0") < 0)
+		return -1;
+
 	reset_tracing_filters();
 	reset_tracing_options(ftrace);
 	return 0;
@@ -444,6 +448,20 @@ static int set_tracing_funcgraph_verbose(struct perf_ftrace *ftrace)
 	return 0;
 }
 
+static int set_tracing_thresh(struct perf_ftrace *ftrace)
+{
+	int ret;
+
+	if (ftrace->graph_thresh == 0)
+		return 0;
+
+	ret = write_tracing_file_int("tracing_thresh", ftrace->graph_thresh);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
 static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
 	char *trace_file;
@@ -543,6 +561,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 		goto out_reset;
 	}
 
+	if (set_tracing_thresh(ftrace) < 0) {
+		pr_err("failed to set tracing thresh\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;
@@ -726,6 +749,7 @@ static int parse_graph_tracer_opts(const struct option *opt,
 		{ .name = "nosleep-time",	.value_ptr = &ftrace->graph_nosleep_time },
 		{ .name = "noirqs",		.value_ptr = &ftrace->graph_noirqs },
 		{ .name = "verbose",		.value_ptr = &ftrace->graph_verbose },
+		{ .name = "thresh",		.value_ptr = &ftrace->graph_thresh },
 		{ .name = NULL, }
 	};
 
@@ -780,7 +804,7 @@ 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,noirqs,verbose",
+		     "graph tracer options, available options: nosleep-time,noirqs,verbose,thresh=<n>",
 		     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

[PATCH v6 14/17] perf: ftrace: allow set graph depth by '--graph-opts'

[Changbin Du]

This is to have a consistent view of all graph tracer options.
The original option '--graph-depth' is marked as deprecated.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 tools/perf/Documentation/perf-ftrace.txt | 5 +----
 tools/perf/builtin-ftrace.c              | 5 ++---
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 96e5e8d7f65c..6f17939b8789 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -95,16 +95,13 @@ OPTIONS
 	This can be used more than once to specify multiple functions.
 	It will be passed to 'set_graph_notrace' in tracefs.
 
--D::
---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.
 	  noirqs       - Ignore functions that happen inside interrupt.
 	  verbose      - Show process names, PIDs, timestamps, etc.
 	  thresh=<n>   - Setup trace duration threshold in microseconds.
+	  depth=<n>    - Set max depth for function graph tracer to follow.
 
 SEE ALSO
 --------
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 5d948239bd70..3ddd7568b456 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -750,6 +750,7 @@ static int parse_graph_tracer_opts(const struct option *opt,
 		{ .name = "noirqs",		.value_ptr = &ftrace->graph_noirqs },
 		{ .name = "verbose",		.value_ptr = &ftrace->graph_verbose },
 		{ .name = "thresh",		.value_ptr = &ftrace->graph_thresh },
+		{ .name = "depth",		.value_ptr = &ftrace->graph_depth },
 		{ .name = NULL, }
 	};
 
@@ -801,10 +802,8 @@ int cmd_ftrace(int argc, const char **argv)
 		     parse_filter_func),
 	OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
 		     "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,noirqs,verbose,thresh=<n>",
+		     "graph tracer options, available options: nosleep-time,noirqs,verbose,thresh=<n>,depth=<n>",
 		     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

[PATCH v6 15/17] perf ftrace: add option -D/--delay to delay tracing

[Changbin Du]

This adds an option '-D/--delay' to allow us to start tracing some
times later after workload is launched.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 tools/perf/Documentation/perf-ftrace.txt |  4 ++++
 tools/perf/builtin-ftrace.c              | 19 ++++++++++++++++---
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 6f17939b8789..077249c979f2 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -38,6 +38,10 @@ OPTIONS
 --pid=::
 	Trace on existing process id (comma separated list).
 
+-D::
+--delay::
+	Time (ms) to wait before starting tracing after program start.
+
 -a::
 --all-cpus::
 	Force system-wide collection.  Scripts run without a <command>
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 3ddd7568b456..64b68331048a 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -47,6 +47,7 @@ struct perf_ftrace {
 	int			graph_noirqs;
 	int			graph_verbose;
 	int			graph_thresh;
+	unsigned int		initial_delay;
 };
 
 struct filter_entry {
@@ -594,13 +595,23 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 	/* display column headers */
 	read_tracing_file_to_stdout("trace");
 
-	if (write_tracing_file("tracing_on", "1") < 0) {
-		pr_err("can't enable tracing\n");
-		goto out_close_fd;
+	if (!ftrace->initial_delay) {
+		if (write_tracing_file("tracing_on", "1") < 0) {
+			pr_err("can't enable tracing\n");
+			goto out_close_fd;
+		}
 	}
 
 	perf_evlist__start_workload(ftrace->evlist);
 
+	if (ftrace->initial_delay) {
+		usleep(ftrace->initial_delay * 1000);
+		if (write_tracing_file("tracing_on", "1") < 0) {
+			pr_err("can't enable tracing\n");
+			goto out_close_fd;
+		}
+	}
+
 	while (!done) {
 		if (poll(&pollfd, 1, -1) < 0)
 			break;
@@ -809,6 +820,8 @@ int cmd_ftrace(int argc, const char **argv)
 		     "size of per cpu buffer", parse_buffer_size),
 	OPT_BOOLEAN(0, "inherit", &ftrace.inherit,
 		    "trace children processes"),
+	OPT_UINTEGER('D', "delay", &ftrace.initial_delay,
+		     "ms to wait before starting tracing after program start"),
 	OPT_END()
 	};
 
-- 
2.25.1

[PATCH v6 16/17] perf: ftrace: Add set_tracing_options() to set all trace options

[Changbin Du]

Now the __cmd_ftrace() becomes a bit long. This moves the trace
option setting code to a separate function set_tracing_options().

Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 tools/perf/builtin-ftrace.c | 118 +++++++++++++++++++-----------------
 1 file changed, 63 insertions(+), 55 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 64b68331048a..edf307f7d716 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -463,110 +463,118 @@ static int set_tracing_thresh(struct perf_ftrace *ftrace)
 	return 0;
 }
 
-static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
+static int set_tracing_options(struct perf_ftrace *ftrace)
 {
-	char *trace_file;
-	int trace_fd;
-	char buf[4096];
-	struct pollfd pollfd = {
-		.events = POLLIN,
-	};
-
-	if (!(perf_cap__capable(CAP_PERFMON) ||
-	      perf_cap__capable(CAP_SYS_ADMIN))) {
-		pr_err("ftrace only works for %s!\n",
-#ifdef HAVE_LIBCAP_SUPPORT
-		"users with the CAP_PERFMON or CAP_SYS_ADMIN capability"
-#else
-		"root"
-#endif
-		);
-		return -1;
-	}
-
-	signal(SIGINT, sig_handler);
-	signal(SIGUSR1, sig_handler);
-	signal(SIGCHLD, sig_handler);
-	signal(SIGPIPE, sig_handler);
-
-	if (ftrace->list_avail_functions)
-		return read_tracing_file_to_stdout("available_filter_functions");
-
-	if (reset_tracing_files(ftrace) < 0) {
-		pr_err("failed to reset ftrace\n");
-		goto out;
-	}
-
-	/* reset ftrace buffer */
-	if (write_tracing_file("trace", "0") < 0)
-		goto out;
-
-	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
-				&ftrace->target, argv, false,
-				ftrace__workload_exec_failed_signal) < 0) {
-		goto out;
-	}
-
 	if (set_tracing_pid(ftrace) < 0) {
 		pr_err("failed to set ftrace pid\n");
-		goto out_reset;
+		return -1;
 	}
 
 	if (set_tracing_cpu(ftrace) < 0) {
 		pr_err("failed to set tracing cpumask\n");
-		goto out_reset;
+		return -1;
 	}
 
 	if (set_tracing_func_stack_trace(ftrace) < 0) {
 		pr_err("failed to set tracing option func_stack_trace\n");
-		goto out_reset;
+		return -1;
 	}
 
 	if (set_tracing_func_irqinfo(ftrace) < 0) {
 		pr_err("failed to set tracing option irq-info\n");
-		goto out_reset;
+		return -1;
 	}
 
 	if (set_tracing_filters(ftrace) < 0) {
 		pr_err("failed to set tracing filters\n");
-		goto out_reset;
+		return -1;
 	}
 
 	if (set_tracing_depth(ftrace) < 0) {
 		pr_err("failed to set graph depth\n");
-		goto out_reset;
+		return -1;
 	}
 
 	if (set_tracing_percpu_buffer_size(ftrace) < 0) {
 		pr_err("failed to set tracing per-cpu buffer size\n");
-		goto out_reset;
+		return -1;
 	}
 
 	if (set_tracing_trace_inherit(ftrace) < 0) {
 		pr_err("failed to set tracing option function-fork\n");
-		goto out_reset;
+		return -1;
 	}
 
 	if (set_tracing_sleep_time(ftrace) < 0) {
 		pr_err("failed to set tracing option sleep-time\n");
-		goto out_reset;
+		return -1;
 	}
 
 	if (set_tracing_funcgraph_irqs(ftrace) < 0) {
 		pr_err("failed to set tracing option funcgraph-irqs\n");
-		goto out_reset;
+		return -1;
 	}
 
 	if (set_tracing_funcgraph_verbose(ftrace) < 0) {
 		pr_err("failed to set tracing option funcgraph-proc/funcgraph-abstime\n");
-		goto out_reset;
+		return -1;
 	}
 
 	if (set_tracing_thresh(ftrace) < 0) {
 		pr_err("failed to set tracing thresh\n");
-		goto out_reset;
+		return -1;
+	}
+
+	return 0;
+}
+
+static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
+{
+	char *trace_file;
+	int trace_fd;
+	char buf[4096];
+	struct pollfd pollfd = {
+		.events = POLLIN,
+	};
+
+	if (!(perf_cap__capable(CAP_PERFMON) ||
+	      perf_cap__capable(CAP_SYS_ADMIN))) {
+		pr_err("ftrace only works for %s!\n",
+#ifdef HAVE_LIBCAP_SUPPORT
+		"users with the CAP_PERFMON or CAP_SYS_ADMIN capability"
+#else
+		"root"
+#endif
+		);
+		return -1;
 	}
 
+	signal(SIGINT, sig_handler);
+	signal(SIGUSR1, sig_handler);
+	signal(SIGCHLD, sig_handler);
+	signal(SIGPIPE, sig_handler);
+
+	if (ftrace->list_avail_functions)
+		return read_tracing_file_to_stdout("available_filter_functions");
+
+	if (reset_tracing_files(ftrace) < 0) {
+		pr_err("failed to reset ftrace\n");
+		goto out;
+	}
+
+	/* reset ftrace buffer */
+	if (write_tracing_file("trace", "0") < 0)
+		goto out;
+
+	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
+				&ftrace->target, argv, false,
+				ftrace__workload_exec_failed_signal) < 0) {
+		goto out;
+	}
+
+	if (set_tracing_options(ftrace) < 0)
+		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;
-- 
2.25.1

[PATCH v6 17/17] perf ftrace: add change log

[Changbin Du]

Add a change log after previous enhancements.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 tools/perf/builtin-ftrace.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index edf307f7d716..326fd03396d5 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -3,6 +3,7 @@
  * builtin-ftrace.c
  *
  * Copyright (c) 2013  LG Electronics,  Namhyung Kim <namhyung@kernel.org>
+ * Copyright (c) 2020  Changbin Du <changbin.du@gmail.com>, significant enhancement.
  */
 
 #include "builtin.h"
-- 
2.25.1

Re: [PATCH v6 02/17] perf ftrace: add option '-F/--funcs' to list available functions

[Arnaldo Carvalho de Melo]

Em Fri, Jul 17, 2020 at 10:36:13PM +0800, Changbin Du escreveu:
> This adds an option '-F/--funcs' to list all available functions to trace,
> which is read from tracing file 'available_filter_functions'.

I'll apply and add a comment stating that this is the same workflow as
for 'perf probe', i.e. stress that the value in 'perf ftrace' as opposed
to use 'trace-cmd' or plain using the debugfs/tracefs interface is to
have a consistent set of options and procedures accross perf and ftrace,
one that allows users to go from:

perf trace --pid 1234

to:

perf ftrace --pid 1234

to:

perf stat --pid 1234

to:

perf top --pid 1234

to:

perf record --pid 1234

to:

perf script --pid 1234

etc

and get different views, for live or postmortem analysis.

- Arnaldo
 
> $ sudo ./perf ftrace -F | head
> trace_initcall_finish_cb
> initcall_blacklisted
> do_one_initcall
> do_one_initcall
> trace_initcall_start_cb
> run_init_process
> try_to_run_init_process
> match_dev_by_label
> match_dev_by_uuid
> rootfs_init_fs_context
> 
> Signed-off-by: Changbin Du <changbin.du@gmail.com>
> 
> ---
> v3: fix return value issue.
> v2: option name '-l/--list-functions' -> '-F/--funcs'
> ---
>  tools/perf/Documentation/perf-ftrace.txt |  4 +++
>  tools/perf/builtin-ftrace.c              | 46 ++++++++++++++++++++++++
>  2 files changed, 50 insertions(+)
> 
> diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
> index 952e46669168..d79560dea19f 100644
> --- a/tools/perf/Documentation/perf-ftrace.txt
> +++ b/tools/perf/Documentation/perf-ftrace.txt
> @@ -30,6 +30,10 @@ OPTIONS
>  --verbose=::
>          Verbosity level.
>  
> +-F::
> +--funcs::
> +        List all available functions to trace.
> +
>  -p::
>  --pid=::
>  	Trace on existing process id (comma separated list).
> diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> index 5f53da87040d..3c0e60fdfe0f 100644
> --- a/tools/perf/builtin-ftrace.c
> +++ b/tools/perf/builtin-ftrace.c
> @@ -32,6 +32,7 @@ struct perf_ftrace {
>  	struct evlist		*evlist;
>  	struct target		target;
>  	const char		*tracer;
> +	bool			list_avail_functions;
>  	struct list_head	filters;
>  	struct list_head	notrace;
>  	struct list_head	graph_funcs;
> @@ -127,6 +128,46 @@ static int append_tracing_file(const char *name, const char *val)
>  	return __write_tracing_file(name, val, true);
>  }
>  
> +static int read_tracing_file_to_stdout(const char *name)
> +{
> +	char buf[4096];
> +	char *file;
> +	int fd;
> +	int ret = -1;
> +
> +	file = get_tracing_file(name);
> +	if (!file) {
> +		pr_debug("cannot get tracing file: %s\n", name);
> +		return -1;
> +	}
> +
> +	fd = open(file, O_RDONLY);
> +	if (fd < 0) {
> +		pr_debug("cannot open tracing file: %s: %s\n",
> +			 name, str_error_r(errno, buf, sizeof(buf)));
> +		goto out;
> +	}
> +
> +	/* read contents to stdout */
> +	while (true) {
> +		int n = read(fd, buf, sizeof(buf));
> +		if (n == 0)
> +			break;
> +		else if (n < 0)
> +			goto out_close;
> +
> +		if (fwrite(buf, n, 1, stdout) != 1)
> +			goto out_close;
> +	}
> +	ret = 0;
> +
> +out_close:
> +	close(fd);
> +out:
> +	put_tracing_file(file);
> +	return ret;
> +}
> +
>  static int reset_tracing_cpu(void);
>  static void reset_tracing_filters(void);
>  
> @@ -301,6 +342,9 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
>  	signal(SIGCHLD, sig_handler);
>  	signal(SIGPIPE, sig_handler);
>  
> +	if (ftrace->list_avail_functions)
> +		return read_tracing_file_to_stdout("available_filter_functions");
> +
>  	if (reset_tracing_files(ftrace) < 0) {
>  		pr_err("failed to reset ftrace\n");
>  		goto out;
> @@ -470,6 +514,8 @@ int cmd_ftrace(int argc, const char **argv)
>  	const struct option ftrace_options[] = {
>  	OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
>  		   "tracer to use: function or function_graph (This option is deprecated)"),
> +	OPT_BOOLEAN('F', "funcs", &ftrace.list_avail_functions,
> +		    "Show available functions to filter"),
>  	OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
>  		   "trace on existing process id"),
>  	OPT_INCR('v', "verbose", &verbose,
> -- 
> 2.25.1
> 

-- 

- Arnaldo