perf lock: Support -t option for 'contention' subcommand

Like perf lock report, it can report lock contention stat of each task.

$ perf lock contention -t
contended total wait max wait avg wait pid comm

5 945.20 us 902.08 us 189.04 us 316167 EventManager_De
33 98.17 us 6.78 us 2.97 us 766063 kworker/0:1-get
7 92.47 us 61.26 us 13.21 us 316170 EventManager_De
14 76.31 us 12.87 us 5.45 us 12949 timedcall
24 76.15 us 12.27 us 3.17 us 767992 sched-pipe
15 75.62 us 11.93 us 5.04 us 15127 switchto-defaul
24 71.84 us 5.59 us 2.99 us 629168 kworker/u513:2-
17 67.41 us 7.94 us 3.96 us 13504 coroner-
1 59.56 us 59.56 us 59.56 us 316165 EventManager_De
14 56.21 us 6.89 us 4.01 us 0 swapper

Signed-off-by: Namhyung Kim <[e-mail]>
Cc: Boqun Feng <[e-mail]>
Cc: Davidlohr Bueso <[e-mail]>
Cc: Ian Rogers <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Waiman Long <[e-mail]>
Cc: Will Deacon <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/Documentation/perf-lock.txt

···
 	and users can customize that using this.  Possible values:
 	contended, wait_total, wait_max, wait_min, avg_wait.
 
+-t::
+--threads::
+	Show per-thread lock contention stat
+
 
 SEE ALSO
 --------

tools/perf/builtin-lock.c

···
 	list_for_each_entry(key, &lock_keys, list)
 		pr_info("%*s ", key->len, key->header);
 
-	pr_info("  %10s   %s\n\n", "type", "caller");
+	if (show_thread_stats)
+		pr_info("  %10s   %s\n\n", "pid", "comm");
+	else
+		pr_info("  %10s   %s\n\n", "type", "caller");
 
 	bad = total = 0;
 	while ((st = pop_from_result())) {
···
 		list_for_each_entry(key, &lock_keys, list) {
 			key->print(key, st);
 			pr_info(" ");
+		}
+
+		if (show_thread_stats) {
+			struct thread *t;
+			int pid = st->addr;
+
+			/* st->addr contains tid of thread */
+			t = perf_session__findnew(session, pid);
+			pr_info("  %10d   %s\n", pid, thread__comm_str(t));
+			continue;
 		}
 
 		pr_info("  %10s   %s\n", get_type_str(st), st->name);
···
 	if (select_key(true))
 		goto out_delete;
 
-	aggr_mode = LOCK_AGGR_CALLER;
+	if (show_thread_stats)
+		aggr_mode = LOCK_AGGR_TASK;
+	else
+		aggr_mode = LOCK_AGGR_CALLER;
 
 	err = perf_session__process_events(session);
 	if (err)
···
 		    "key for sorting (contended / wait_total / wait_max / wait_min / avg_wait)"),
 	OPT_STRING('F', "field", &output_fields, "contended,wait_total,wait_max,avg_wait",
 		    "output fields (contended / wait_total / wait_max / wait_min / avg_wait)"),
+	OPT_BOOLEAN('t', "threads", &show_thread_stats,
+		    "show per-thread lock stats"),
 	OPT_PARENT(lock_options)
 	};