Same as 'perf probe -F', this patch adds filter support for the ftrace
subcommand option '-F, --funcs <[FILTER]>'.
Here is an example that only lists functions which start with 'vfs_':
$ sudo perf ftrace -F vfs_*
vfs_fadvise
vfs_fallocate
vfs_truncate
vfs_open
vfs_setpos
vfs_llseek
vfs_readf
vfs_writef
...
Suggested-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Changbin Du <[email protected]>
---
tools/perf/Documentation/perf-ftrace.txt | 3 +-
tools/perf/builtin-ftrace.c | 84 ++++++++++++++++++++++--
2 files changed, 80 insertions(+), 7 deletions(-)
diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 78358af9a1c4..1e91121bac0f 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -33,7 +33,8 @@ OPTIONS
-F::
--funcs::
- List all available functions to trace.
+ List available functions to trace. It accepts a pattern to
+ only list interested functions.
-p::
--pid=::
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 1d44bc2f63d8..9366fad591dc 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -25,6 +25,7 @@
#include "target.h"
#include "cpumap.h"
#include "thread_map.h"
+#include "strfilter.h"
#include "util/cap.h"
#include "util/config.h"
#include "util/units.h"
@@ -36,7 +37,6 @@ 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;
@@ -181,6 +181,40 @@ static int read_tracing_file_to_stdout(const char *name)
return ret;
}
+static int read_tracing_file_by_line(const char *name,
+ void (*cb)(char *str, void *arg),
+ void *cb_arg)
+{
+ char *line = NULL;
+ size_t len = 0;
+ char *file;
+ FILE *fp;
+
+ file = get_tracing_file(name);
+ if (!file) {
+ pr_debug("cannot get tracing file: %s\n", name);
+ return -1;
+ }
+
+ fp = fopen(file, "r");
+ if (fp == NULL) {
+ pr_debug("cannot open tracing file: %s\n", name);
+ put_tracing_file(file);
+ return -1;
+ }
+
+ while (getline(&line, &len, fp) != -1) {
+ cb(line, cb_arg);
+ }
+
+ if (line)
+ free(line);
+
+ fclose(fp);
+ put_tracing_file(file);
+ return 0;
+}
+
static int write_tracing_file_int(const char *name, int value)
{
char buf[16];
@@ -557,9 +591,6 @@ 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;
@@ -683,6 +714,46 @@ static int perf_ftrace_config(const char *var, const char *value, void *cb)
return -1;
}
+static void list_function_cb(char *str, void *arg)
+{
+ struct strfilter *filter = (struct strfilter *)arg;
+
+ if (strfilter__compare(filter, str))
+ printf("%s", str);
+}
+
+static int opt_list_avail_functions(const struct option *opt __maybe_unused,
+ const char *str, int unset)
+{
+ struct strfilter *filter;
+ const char *err = NULL;
+ int ret;
+
+ if (unset || !str)
+ return -1;
+
+ filter = strfilter__new(str, &err);
+ if (!filter)
+ return err ? -EINVAL : -ENOMEM;
+
+ ret = strfilter__or(filter, str, &err);
+ if (ret == -EINVAL) {
+ pr_err("Filter parse error at %td.\n", err - str + 1);
+ pr_err("Source: \"%s\"\n", str);
+ pr_err(" %*c\n", (int)(err - str + 1), '^');
+ strfilter__delete(filter);
+ return ret;
+ }
+
+ ret = read_tracing_file_by_line("available_filter_functions",
+ list_function_cb, filter);
+ strfilter__delete(filter);
+ if (ret < 0)
+ return ret;
+
+ exit(0);
+}
+
static int parse_filter_func(const struct option *opt, const char *str,
int unset __maybe_unused)
{
@@ -817,8 +888,9 @@ 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_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
+ "Show available functions to filter",
+ opt_list_avail_functions, "*"),
OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
"Trace on existing process id"),
/* TODO: Add short option -t after -t/--tracer can be removed. */
--
2.25.1