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authorChangbin Du <changbin.du@gmail.com>2020-08-08 10:31:25 +0800
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-08-14 08:36:38 -0300
commitd6d81bfe429ee7e3e59388d16741b354a2484f0f (patch)
tree293518febdc588b4f20910aa32729505ed15f784 /tools
parenteb6d31ae22d7767789e3c079444157ea40114884 (diff)
downloadlinux-d6d81bfe429ee7e3e59388d16741b354a2484f0f.tar.bz2
perf ftrace: Add option '-F/--funcs' to list available functions
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 $ Committer notes: This is the same command line option and for the same purpose as in 'perf probe'. Signed-off-by: Changbin Du <changbin.du@gmail.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: http://lore.kernel.org/lkml/20200808023141.14227-3-changbin.du@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/Documentation/perf-ftrace.txt4
-rw-r--r--tools/perf/builtin-ftrace.c46
2 files changed, 50 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 821d4d334a09..4f5628445a63 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -31,6 +31,10 @@ 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 048a11192b59..1ebf71ecc1a8 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -33,6 +33,7 @@ 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;
@@ -128,6 +129,46 @@ 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);
@@ -302,6 +343,9 @@ 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;
@@ -487,6 +531,8 @@ int cmd_ftrace(int argc, const char **argv)
const struct option ftrace_options[] = {
OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
"tracer to use: function_graph(default) or function"),
+ 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,