I implemented the feature of tracking only specified threads to perf lock.
With -t option, users can specify which threads should be tracked.
Example of usage:
| % sudo ./perf lock info -t # info -t is convenient with this feature
| Thread ID: comm
| 0: swapper
| 1: init
| 12: migration/3
| 13: ksoftirqd/3
| 27: events/0
| 28: events/1
| 29: events/2
| 30: events/3
| 31: events/4
| 857: kondemand/0
| 858: kondemand/1
| 859: kondemand/2
| ...
| % sudo ./perf lock -t 27,28,29,30,31 report # track only these threads
| Name acquired contended total wait (ns) max wait (ns) min wait (ns)
|
| &(&cwq->lock)->r... 4 0 0 0 0
| &(&cwq->lock)->r... 4 0 0 0 0
| key 2 0 0 0 0
| key 2 0 0 0 0
| &(&tty->buf.lock... 2 0 0 0 0
| &(&tty->buf.lock... 2 0 0 0 0
| tty_ldisc_lock 2 0 0 0 0
| &(&base->lock)->... 2 0 0 0 0
| &(&(&(*({ do { c... 2 0 0 0 0
| &(&(&(*({ do { c... 2 0 0 0 0
| &(&cwq->lock)->r... 2 0 0 0 0
I believe that this is convenient feature because perf itself acquires lots of locks.
Could you queue this, Frederic?
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
---
tools/perf/builtin-lock.c | 71 +++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 68 insertions(+), 3 deletions(-)
diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index 010a7c8..7c75c44 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -23,6 +23,7 @@
#include <linux/list.h>
#include <linux/hash.h>
+static int do_info;
static struct perf_session *session;
/* based on kernel/lockdep.c */
@@ -34,6 +35,27 @@ static struct list_head lockhash_table[LOCKHASH_SIZE];
#define __lockhashfn(key) hash_long((unsigned long)key, LOCKHASH_BITS)
#define lockhashentry(key) (lockhash_table + __lockhashfn((key)))
+static u32 *track_thread_array;
+static int track_thread_array_length;
+
+static int is_track_thread_do(u32 tid)
+{
+ int i;
+
+ for (i = 0; i < track_thread_array_length; i++) {
+ if (track_thread_array[i] == tid)
+ return 1;
+ }
+ return 0;
+}
+
+static int is_track_thread_nop(u32 tid __used)
+{
+ return 1;
+}
+
+static int (*is_track_thread)(u32) = is_track_thread_nop;
+
struct lock_stat {
struct list_head hash_entry;
struct rb_node rb; /* used for sorting */
@@ -315,6 +337,7 @@ alloc_failed:
}
static char const *input_name = "perf.data";
+static char const *track_threads_str;
struct raw_event_sample {
u32 size;
@@ -829,6 +852,9 @@ static int process_sample_event(event_t *self, struct perf_session *s)
bzero(&data, sizeof(data));
event__parse_sample(self, s->sample_type, &data);
+ if (!do_info && !is_track_thread(data.tid))
+ return 0;
+
thread = perf_session__findnew(s, data.tid);
if (thread == NULL) {
pr_debug("problem processing %d event, skipping it.\n",
@@ -868,8 +894,41 @@ static void sort_result(void)
}
}
+static void parse_track_threads(void)
+{
+ char *tmp, *tok, *str;
+
+ if (!track_threads_str)
+ return;
+
+ str = strdup(track_threads_str);
+ if (!str)
+ die("Memory allocation failed\n");
+
+ tok = strtok_r(str, ", ", &tmp);
+ if (!tok)
+ return;
+ track_thread_array = zalloc(sizeof(u32));
+ if (!track_thread_array)
+ die("Memory allocation failed\n");
+ track_thread_array[0] = atoi(tok);
+ track_thread_array_length = 1;
+ is_track_thread = is_track_thread_do;
+
+ for (tok = strtok_r(NULL, ", ", &tmp);
+ tok; tok = strtok_r(NULL, ", ", &tmp)) {
+ track_thread_array = realloc(track_thread_array,
+ sizeof(u32) *
+ ++track_thread_array_length);
+ if (!track_thread_array)
+ die("Memory allocation failed\n");
+ track_thread_array[track_thread_array_length - 1] = atoi(tok);
+ }
+}
+
static void __cmd_report(void)
{
+ parse_track_threads();
setup_pager();
select_key();
read_events();
@@ -908,9 +967,14 @@ static const char * const lock_usage[] = {
};
static const struct option lock_options[] = {
- OPT_STRING('i', "input", &input_name, "file", "input file name"),
- OPT_INCR('v', "verbose", &verbose, "be more verbose (show symbol address, etc)"),
- OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace, "dump raw trace in ASCII"),
+ OPT_STRING('i', "input", &input_name,
+ "file", "input file name"),
+ OPT_INCR('v', "verbose", &verbose,
+ "be more verbose (show symbol address, etc)"),
+ OPT_BOOLEAN('D', "dump-raw-trace",
+ &dump_trace, "dump raw trace in ASCII"),
+ OPT_STRING('t', "threads", &track_threads_str,
+ NULL, "thread IDs to track"),
OPT_END()
};
@@ -981,6 +1045,7 @@ int cmd_lock(int argc, const char **argv, const char *prefix __used)
usage_with_options(info_usage, info_options);
}
/* recycling report_lock_ops */
+ do_info = 1;
trace_handler = &report_lock_ops;
setup_pager();
read_events();
--
1.6.5.2
--
