char cut_name[20];
        int bad, total;
 
-       printf("%20s ", "Name");
-       printf("%10s ", "acquired");
-       printf("%10s ", "contended");
+       pr_info("%20s ", "Name");
+       pr_info("%10s ", "acquired");
+       pr_info("%10s ", "contended");
 
-       printf("%15s ", "total wait (ns)");
-       printf("%15s ", "max wait (ns)");
-       printf("%15s ", "min wait (ns)");
+       pr_info("%15s ", "total wait (ns)");
+       pr_info("%15s ", "max wait (ns)");
+       pr_info("%15s ", "min wait (ns)");
 
-       printf("\n\n");
+       pr_info("\n\n");
 
        bad = total = 0;
        while ((st = pop_from_result())) {
 
                if (strlen(st->name) < 16) {
                        /* output raw name */
-                       printf("%20s ", st->name);
+                       pr_info("%20s ", st->name);
                } else {
                        strncpy(cut_name, st->name, 16);
                        cut_name[16] = '.';
                        cut_name[18] = '.';
                        cut_name[19] = '\0';
                        /* cut off name for saving output style */
-                       printf("%20s ", cut_name);
+                       pr_info("%20s ", cut_name);
                }
 
-               printf("%10u ", st->nr_acquired);
-               printf("%10u ", st->nr_contended);
+               pr_info("%10u ", st->nr_acquired);
+               pr_info("%10u ", st->nr_contended);
 
-               printf("%15llu ", st->wait_time_total);
-               printf("%15llu ", st->wait_time_max);
-               printf("%15llu ", st->wait_time_min == ULLONG_MAX ?
+               pr_info("%15llu ", st->wait_time_total);
+               pr_info("%15llu ", st->wait_time_max);
+               pr_info("%15llu ", st->wait_time_min == ULLONG_MAX ?
                       0 : st->wait_time_min);
-               printf("\n");
+               pr_info("\n");
        }
 
        {
                const char *name[4] =
                        { "acquire", "acquired", "contended", "release" };
 
-               printf("\n=== output for debug===\n\n");
-               printf("bad:%d, total:%d\n", bad, total);
-               printf("bad rate:%f\n", (double)(bad / total));
+               pr_debug("\n=== output for debug===\n\n");
+               pr_debug("bad:%d, total:%d\n", bad, total);
+               pr_debug("bad rate:%f\n", (double)(bad / total));
 
-               printf("histogram of events caused bad sequence\n");
+               pr_debug("histogram of events caused bad sequence\n");
                for (i = 0; i < 4; i++)
-                       printf(" %10s: %d\n", name[i], bad_hist[i]);
+                       pr_debug(" %10s: %d\n", name[i], bad_hist[i]);
        }
 }
 
+static int                     info_threads;
+static int                     info_map;
+
+static void dump_threads(void)
+{
+       struct thread_stat *st;
+       struct rb_node *node;
+       struct thread *t;
+
+       pr_info("%10s: comm\n", "Thread ID");
+
+       node = rb_first(&thread_stats);
+       while (node) {
+               st = container_of(node, struct thread_stat, rb);
+               t = perf_session__findnew(session, st->tid);
+               pr_info("%10d: %s\n", st->tid, t->comm);
+               node = rb_next(node);
+       };
+}
+
 static void dump_map(void)
 {
        unsigned int i;
        struct lock_stat *st;
 
+       pr_info("Address of instance: name of class\n");
        for (i = 0; i < LOCKHASH_SIZE; i++) {
                list_for_each_entry(st, &lockhash_table[i], hash_entry) {
-                       printf("%p: %s\n", st->addr, st->name);
+                       pr_info(" %p: %s\n", st->addr, st->name);
                }
        }
 }
 
+static void dump_info(void)
+{
+       if (info_threads)
+               dump_threads();
+       else if (info_map)
+               dump_map();
+       else
+               die("Unknown type of information\n");
+}
+
 static int process_sample_event(event_t *self, struct perf_session *s)
 {
        struct sample_data data;
        OPT_END()
 };
 
+static const char * const info_usage[] = {
+       "perf lock info [<options>]",
+       NULL
+};
+
+static const struct option info_options[] = {
+       OPT_BOOLEAN('t', "threads", &info_threads,
+                   "dump thread list in perf.data"),
+       OPT_BOOLEAN('m', "map", &info_map,
+                   "map of lock instances (name:address table)"),
+       OPT_END()
+};
+
 static const char * const lock_usage[] = {
        "perf lock [<options>] {record|trace|report}",
        NULL
        } else if (!strcmp(argv[0], "trace")) {
                /* Aliased to 'perf trace' */
                return cmd_trace(argc, argv, prefix);
-       } else if (!strcmp(argv[0], "map")) {
+       } else if (!strcmp(argv[0], "info")) {
+               if (argc) {
+                       argc = parse_options(argc, argv,
+                                            info_options, info_usage, 0);
+                       if (argc)
+                               usage_with_options(info_usage, info_options);
+               }
                /* recycling report_lock_ops */
                trace_handler = &report_lock_ops;
                setup_pager();
                read_events();
-               dump_map();
+               dump_info();
        } else {
                usage_with_options(lock_usage, lock_options);
        }