[PATCH -perf/perf/core 6/6] perf probe: Add filters support for available functions

Masami Hiramatsu
2011-01-13T12:52:06Z

Add filters support for available function list.
Default filter is "!_*" for filtering out local-purpose
symbols.

e.g.)
# perf probe --filter="add*" -F
add_disk
add_disk_randomness
add_input_randomness
add_interrupt_randomness
add_memory
add_page_to_unevictable_list
add_page_wait_queue
...

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Chase Douglas <chase.douglas@canonical.com>
Cc: linux-kernel@vger.kernel.org
---

tools/perf/Documentation/perf-probe.txt | 9 +++++----
tools/perf/builtin-probe.c | 19 +++++++++++++------
tools/perf/util/probe-event.c | 23 +++++++++++++----------
tools/perf/util/probe-event.h | 2 +-
4 files changed, 32 insertions(+), 21 deletions(-)

diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index 7542e8a..32d4af3 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -74,9 +74,10 @@ OPTIONS
variables.

--filter=FILTER::
- (Only for --vars) Set filter for variables. FILTER is a combination of
- glob pattern, see FILTER PATTERN for detail.
- Default FILTER is "!__k???tab_* & !__crc_*".
+ (Only for --vars and --funcs) Set filter for variables. FILTER is a
+ combination of glob pattern, see FILTER PATTERN for detail.
+ Default FILTER is "!__k???tab_* & !__crc_*" for --vars, and "!_*"
+ for --funcs.
If several filters are specified, only the last filter is valid.

-f::
@@ -143,7 +144,7 @@ This provides some sort of flexibility and robustness to probe point definitions

FILTER PATTERN
--------------
- The filter pattern is glob matching pattern(s) to filter variables.
+ The filter pattern is glob matching pattern(s) to filter variables or functions.
In addition, you can use "!" for specifying filter-out rule. You also can give several rules combined with "&" or "|", and fold those rules as one rule by using "(" ")".

e.g.
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index abb423e..fcde003 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -45,6 +45,7 @@
#include "util/probe-event.h"

#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
+#define DEFAULT_FUNC_FILTER "!_*"
#define MAX_PATH_LEN 256

/* Session management structure */
@@ -159,6 +160,7 @@ static int opt_show_vars(const struct option *opt __used,

return ret;
}
+#endif

static int opt_set_filter(const struct option *opt __used,
const char *str, int unset __used)
@@ -180,7 +182,6 @@ static int opt_set_filter(const struct option *opt __used,

return 0;
}
-#endif

static const char * const probe_usage[] = {
"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
@@ -236,10 +237,6 @@ static const struct option options[] = {
"Show accessible variables on PROBEDEF", opt_show_vars),
OPT_BOOLEAN('\0', "externs", &params.show_ext_vars,
"Show external variables too (with --vars only)"),
- OPT_CALLBACK('\0', "filter", NULL,
- "[!]FILTER", "Set a variable filter (with --vars only)\n"
- "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\")",
- opt_set_filter),
OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
"file", "vmlinux pathname"),
OPT_STRING('s', "source", &symbol_conf.source_prefix,
@@ -252,6 +249,11 @@ static const struct option options[] = {
"Set how many probe points can be found for a probe."),
OPT_BOOLEAN('F', "funcs", &params.show_funcs,
"Show potential probe-able functions."),
+ OPT_CALLBACK('\0', "filter", NULL,
+ "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
+ "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
+ "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
+ opt_set_filter),
OPT_END()
};

@@ -322,7 +324,12 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used)
pr_err(" Error: Don't use --funcs with --vars.\n");
usage_with_options(probe_usage, options);
}
- ret = show_available_funcs(params.target_module);
+ if (!params.filter)
+ params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
+ NULL);
+ ret = show_available_funcs(params.target_module,
+ params.filter);
+ strfilter__delete(params.filter);
if (ret < 0)
pr_err(" Error: Failed to show functions."
" (%d)\n", ret);
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index b231a20..ebf73ae 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1951,21 +1951,23 @@ int del_perf_probe_events(struct strlist *dellist)

return ret;
}
+/* TODO: don't use a global variable for filter ... */
+static struct strfilter *available_func_filter;

/*
- * If a symbol corresponds to a function with global binding return 0.
- * For all others return 1.
+ * If a symbol corresponds to a function with global binding and
+ * matches filter return 0. For all others return 1.
*/
-static int filter_non_global_functions(struct map *map __unused,
- struct symbol *sym)
+static int filter_available_functions(struct map *map __unused,
+ struct symbol *sym)
{
- if (sym->binding != STB_GLOBAL)
- return 1;
-
- return 0;
+ if (sym->binding == STB_GLOBAL &&
+ strfilter__match(available_func_filter, sym->name))
+ return 0;
+ return 1;
}

-int show_available_funcs(const char *module)
+int show_available_funcs(const char *module, struct strfilter *_filter)
{
struct map *map;
int ret;
@@ -1981,7 +1983,8 @@ int show_available_funcs(const char *module)
pr_err("Failed to find %s map.\n", (module) ? : "kernel");
return -EINVAL;
}
- if (map__load(map, filter_non_global_functions)) {
+ available_func_filter = _filter;
+ if (map__load(map, filter_available_functions)) {
pr_err("Failed to load map.\n");
return -EINVAL;
}
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index 4e80b2b..3434fc9 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -128,7 +128,7 @@ extern int show_line_range(struct line_range *lr, const char *module);
extern int show_available_vars(struct perf_probe_event *pevs, int npevs,
int max_probe_points, const char *module,
struct strfilter *filter, bool externs);
-extern int show_available_funcs(const char *module);
+extern int show_available_funcs(const char *module, struct strfilter *filter);

/* Maximum index number of event-name postfix */