perf lock: Add 'contention' subcommand · tjh.dev/kernel@528b9ca

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tools

perf

Documentation

perf-lock.txt

builtin-lock.c

+3 -1

tools/perf/Documentation/perf-lock.txt

··· 8 8 SYNOPSIS 9 9 -------- 10 10 [verse] 11 - 'perf lock' {record|report|script|info} 11 + 'perf lock' {record|report|script|info|contention} 12 12 13 13 DESCRIPTION 14 14 ----------- ··· 26 26 27 27 'perf lock info' shows metadata like threads or addresses 28 28 of lock instances. 29 + 30 + 'perf lock contention' shows contention statistics. 29 31 30 32 COMMON OPTIONS 31 33 --------------

+211 -1

tools/perf/builtin-lock.c

··· 145 145 */ 146 146 #define CONTENTION_STACK_SKIP 3 147 147 148 + /* 149 + * flags for lock:contention_begin 150 + * Imported from include/trace/events/lock.h. 151 + */ 152 + #define LCB_F_SPIN (1U << 0) 153 + #define LCB_F_READ (1U << 1) 154 + #define LCB_F_WRITE (1U << 2) 155 + #define LCB_F_RT (1U << 3) 156 + #define LCB_F_PERCPU (1U << 4) 157 + #define LCB_F_MUTEX (1U << 5) 158 + 159 + 148 160 static u64 sched_text_start; 149 161 static u64 sched_text_end; 150 162 static u64 lock_text_start; ··· 1034 1022 return -1; 1035 1023 } 1036 1024 1025 + static u64 callchain_id(struct evsel *evsel, struct perf_sample *sample) 1026 + { 1027 + struct callchain_cursor *cursor = &callchain_cursor; 1028 + struct thread *thread; 1029 + u64 hash = 0; 1030 + int skip = 0; 1031 + int ret; 1032 + 1033 + thread = machine__findnew_thread(&session->machines.host, 1034 + -1, sample->pid); 1035 + if (thread == NULL) 1036 + return -1; 1037 + 1038 + /* use caller function name from the callchain */ 1039 + ret = thread__resolve_callchain(thread, cursor, evsel, sample, 1040 + NULL, NULL, CONTENTION_STACK_DEPTH); 1041 + thread__put(thread); 1042 + 1043 + if (ret != 0) 1044 + return -1; 1045 + 1046 + callchain_cursor_commit(cursor); 1047 + 1048 + while (true) { 1049 + struct callchain_cursor_node *node; 1050 + 1051 + node = callchain_cursor_current(cursor); 1052 + if (node == NULL) 1053 + break; 1054 + 1055 + /* skip first few entries - for lock functions */ 1056 + if (++skip <= CONTENTION_STACK_SKIP) 1057 + goto next; 1058 + 1059 + if (node->ms.sym && is_lock_function(node->ip)) 1060 + goto next; 1061 + 1062 + hash ^= hash_long((unsigned long)node->ip, 64); 1063 + 1064 + next: 1065 + callchain_cursor_advance(cursor); 1066 + } 1067 + return hash; 1068 + } 1069 + 1037 1070 static int report_lock_contention_begin_event(struct evsel *evsel, 1038 1071 struct perf_sample *sample) 1039 1072 { ··· 1096 1039 key = sample->tid; 1097 1040 break; 1098 1041 case LOCK_AGGR_CALLER: 1042 + key = callchain_id(evsel, sample); 1043 + break; 1099 1044 default: 1100 1045 pr_err("Invalid aggregation mode: %d\n", aggr_mode); 1101 1046 return -EINVAL; ··· 1179 1120 key = sample->tid; 1180 1121 break; 1181 1122 case LOCK_AGGR_CALLER: 1123 + key = callchain_id(evsel, sample); 1124 + break; 1182 1125 default: 1183 1126 pr_err("Invalid aggregation mode: %d\n", aggr_mode); 1184 1127 return -EINVAL; ··· 1243 1182 .contention_begin_event = report_lock_contention_begin_event, 1244 1183 .contention_end_event = report_lock_contention_end_event, 1245 1184 }; 1185 + 1186 + static struct trace_lock_handler contention_lock_ops = { 1187 + .contention_begin_event = report_lock_contention_begin_event, 1188 + .contention_end_event = report_lock_contention_end_event, 1189 + }; 1190 + 1246 1191 1247 1192 static struct trace_lock_handler *trace_handler; 1248 1193 ··· 1495 1428 } 1496 1429 } 1497 1430 1431 + static const char *get_type_str(struct lock_stat *st) 1432 + { 1433 + static const struct { 1434 + unsigned int flags; 1435 + const char *name; 1436 + } table[] = { 1437 + { 0, "semaphore" }, 1438 + { LCB_F_SPIN, "spinlock" }, 1439 + { LCB_F_SPIN | LCB_F_READ, "rwlock:R" }, 1440 + { LCB_F_SPIN | LCB_F_WRITE, "rwlock:W"}, 1441 + { LCB_F_READ, "rwsem:R" }, 1442 + { LCB_F_WRITE, "rwsem:W" }, 1443 + { LCB_F_RT, "rtmutex" }, 1444 + { LCB_F_RT | LCB_F_READ, "rwlock-rt:R" }, 1445 + { LCB_F_RT | LCB_F_WRITE, "rwlock-rt:W"}, 1446 + { LCB_F_PERCPU | LCB_F_READ, "pcpu-sem:R" }, 1447 + { LCB_F_PERCPU | LCB_F_WRITE, "pcpu-sem:W" }, 1448 + { LCB_F_MUTEX, "mutex" }, 1449 + { LCB_F_MUTEX | LCB_F_SPIN, "mutex" }, 1450 + }; 1451 + 1452 + for (unsigned int i = 0; i < ARRAY_SIZE(table); i++) { 1453 + if (table[i].flags == st->flags) 1454 + return table[i].name; 1455 + } 1456 + return "unknown"; 1457 + } 1458 + 1459 + static void sort_contention_result(void) 1460 + { 1461 + sort_result(); 1462 + } 1463 + 1464 + static void print_contention_result(void) 1465 + { 1466 + struct lock_stat *st; 1467 + struct lock_key *key; 1468 + int bad, total; 1469 + 1470 + list_for_each_entry(key, &lock_keys, list) 1471 + pr_info("%*s ", key->len, key->header); 1472 + 1473 + pr_info(" %10s %s\n\n", "type", "caller"); 1474 + 1475 + bad = total = 0; 1476 + while ((st = pop_from_result())) { 1477 + total++; 1478 + if (st->broken) 1479 + bad++; 1480 + 1481 + list_for_each_entry(key, &lock_keys, list) { 1482 + key->print(key, st); 1483 + pr_info(" "); 1484 + } 1485 + 1486 + pr_info(" %10s %s\n", get_type_str(st), st->name); 1487 + } 1488 + 1489 + print_bad_events(bad, total); 1490 + } 1491 + 1498 1492 static const struct evsel_str_handler lock_tracepoints[] = { 1499 1493 { "lock:lock_acquire", evsel__process_lock_acquire, }, /* CONFIG_LOCKDEP */ 1500 1494 { "lock:lock_acquired", evsel__process_lock_acquired, }, /* CONFIG_LOCKDEP, CONFIG_LOCK_STAT */ ··· 1635 1507 perf_session__delete(session); 1636 1508 return err; 1637 1509 } 1510 + 1511 + static int __cmd_contention(void) 1512 + { 1513 + int err = -EINVAL; 1514 + struct perf_tool eops = { 1515 + .sample = process_sample_event, 1516 + .comm = perf_event__process_comm, 1517 + .mmap = perf_event__process_mmap, 1518 + .ordered_events = true, 1519 + }; 1520 + struct perf_data data = { 1521 + .path = input_name, 1522 + .mode = PERF_DATA_MODE_READ, 1523 + .force = force, 1524 + }; 1525 + 1526 + session = perf_session__new(&data, &eops); 1527 + if (IS_ERR(session)) { 1528 + pr_err("Initializing perf session failed\n"); 1529 + return PTR_ERR(session); 1530 + } 1531 + 1532 + /* for lock function check */ 1533 + symbol_conf.sort_by_name = true; 1534 + symbol__init(&session->header.env); 1535 + 1536 + if (!perf_session__has_traces(session, "lock record")) 1537 + goto out_delete; 1538 + 1539 + if (!evlist__find_evsel_by_str(session->evlist, "lock:contention_begin")) { 1540 + pr_err("lock contention evsel not found\n"); 1541 + goto out_delete; 1542 + } 1543 + 1544 + if (perf_session__set_tracepoints_handlers(session, contention_tracepoints)) { 1545 + pr_err("Initializing perf session tracepoint handlers failed\n"); 1546 + goto out_delete; 1547 + } 1548 + 1549 + if (setup_output_field("contended,wait_total,wait_max,avg_wait")) 1550 + goto out_delete; 1551 + 1552 + sort_key = "wait_total"; 1553 + if (select_key()) 1554 + goto out_delete; 1555 + 1556 + aggr_mode = LOCK_AGGR_CALLER; 1557 + 1558 + err = perf_session__process_events(session); 1559 + if (err) 1560 + goto out_delete; 1561 + 1562 + setup_pager(); 1563 + 1564 + sort_contention_result(); 1565 + print_contention_result(); 1566 + 1567 + out_delete: 1568 + perf_session__delete(session); 1569 + return err; 1570 + } 1571 + 1638 1572 1639 1573 static int __cmd_record(int argc, const char **argv) 1640 1574 { ··· 1816 1626 OPT_PARENT(lock_options) 1817 1627 }; 1818 1628 1629 + const struct option contention_options[] = { 1630 + OPT_PARENT(lock_options) 1631 + }; 1632 + 1819 1633 const char * const info_usage[] = { 1820 1634 "perf lock info [<options>]", 1821 1635 NULL 1822 1636 }; 1823 1637 const char *const lock_subcommands[] = { "record", "report", "script", 1824 - "info", NULL }; 1638 + "info", "contention", 1639 + "contention", NULL }; 1825 1640 const char *lock_usage[] = { 1826 1641 NULL, 1827 1642 NULL 1828 1643 }; 1829 1644 const char * const report_usage[] = { 1830 1645 "perf lock report [<options>]", 1646 + NULL 1647 + }; 1648 + const char * const contention_usage[] = { 1649 + "perf lock contention [<options>]", 1831 1650 NULL 1832 1651 }; 1833 1652 unsigned int i; ··· 1874 1675 /* recycling report_lock_ops */ 1875 1676 trace_handler = &report_lock_ops; 1876 1677 rc = __cmd_report(true); 1678 + } else if (strlen(argv[0]) > 2 && strstarts("contention", argv[0])) { 1679 + trace_handler = &contention_lock_ops; 1680 + if (argc) { 1681 + argc = parse_options(argc, argv, contention_options, 1682 + contention_usage, 0); 1683 + if (argc) { 1684 + usage_with_options(contention_usage, 1685 + contention_options); 1686 + } 1687 + } 1688 + rc = __cmd_contention(); 1877 1689 } else { 1878 1690 usage_with_options(lock_usage, lock_options); 1879 1691 }

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