1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "event_selection_set.h" 18 19 #include <android-base/logging.h> 20 21 #include "environment.h" 22 #include "event_attr.h" 23 #include "event_type.h" 24 #include "IOEventLoop.h" 25 #include "perf_regs.h" 26 #include "utils.h" 27 28 constexpr uint64_t DEFAULT_SAMPLE_FREQ_FOR_NONTRACEPOINT_EVENT = 4000; 29 constexpr uint64_t DEFAULT_SAMPLE_PERIOD_FOR_TRACEPOINT_EVENT = 1; 30 31 bool IsBranchSamplingSupported() { 32 const EventType* type = FindEventTypeByName("cpu-cycles"); 33 if (type == nullptr) { 34 return false; 35 } 36 perf_event_attr attr = CreateDefaultPerfEventAttr(*type); 37 attr.sample_type |= PERF_SAMPLE_BRANCH_STACK; 38 attr.branch_sample_type = PERF_SAMPLE_BRANCH_ANY; 39 return IsEventAttrSupported(attr); 40 } 41 42 bool IsDwarfCallChainSamplingSupported() { 43 const EventType* type = FindEventTypeByName("cpu-cycles"); 44 if (type == nullptr) { 45 return false; 46 } 47 perf_event_attr attr = CreateDefaultPerfEventAttr(*type); 48 attr.sample_type |= 49 PERF_SAMPLE_CALLCHAIN | PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER; 50 attr.exclude_callchain_user = 1; 51 attr.sample_regs_user = GetSupportedRegMask(GetBuildArch()); 52 attr.sample_stack_user = 8192; 53 return IsEventAttrSupported(attr); 54 } 55 56 bool EventSelectionSet::BuildAndCheckEventSelection( 57 const std::string& event_name, EventSelection* selection) { 58 std::unique_ptr<EventTypeAndModifier> event_type = ParseEventType(event_name); 59 if (event_type == nullptr) { 60 return false; 61 } 62 if (for_stat_cmd_) { 63 if (event_type->event_type.name == "cpu-clock" || 64 event_type->event_type.name == "task-clock") { 65 if (event_type->exclude_user || event_type->exclude_kernel) { 66 LOG(ERROR) << "Modifier u and modifier k used in event type " 67 << event_type->event_type.name 68 << " are not supported by the kernel."; 69 return false; 70 } 71 } 72 } 73 selection->event_type_modifier = *event_type; 74 selection->event_attr = CreateDefaultPerfEventAttr(event_type->event_type); 75 selection->event_attr.exclude_user = event_type->exclude_user; 76 selection->event_attr.exclude_kernel = event_type->exclude_kernel; 77 selection->event_attr.exclude_hv = event_type->exclude_hv; 78 selection->event_attr.exclude_host = event_type->exclude_host; 79 selection->event_attr.exclude_guest = event_type->exclude_guest; 80 selection->event_attr.precise_ip = event_type->precise_ip; 81 if (!IsEventAttrSupported(selection->event_attr)) { 82 LOG(ERROR) << "Event type '" << event_type->name 83 << "' is not supported on the device"; 84 return false; 85 } 86 selection->event_fds.clear(); 87 88 for (const auto& group : groups_) { 89 for (const auto& sel : group) { 90 if (sel.event_type_modifier.name == selection->event_type_modifier.name) { 91 LOG(ERROR) << "Event type '" << sel.event_type_modifier.name 92 << "' appears more than once"; 93 return false; 94 } 95 } 96 } 97 return true; 98 } 99 100 bool EventSelectionSet::AddEventType(const std::string& event_name) { 101 return AddEventGroup(std::vector<std::string>(1, event_name)); 102 } 103 104 bool EventSelectionSet::AddEventGroup( 105 const std::vector<std::string>& event_names) { 106 EventSelectionGroup group; 107 for (const auto& event_name : event_names) { 108 EventSelection selection; 109 if (!BuildAndCheckEventSelection(event_name, &selection)) { 110 return false; 111 } 112 group.push_back(std::move(selection)); 113 } 114 groups_.push_back(std::move(group)); 115 UnionSampleType(); 116 return true; 117 } 118 119 std::vector<const EventType*> EventSelectionSet::GetTracepointEvents() const { 120 std::vector<const EventType*> result; 121 for (const auto& group : groups_) { 122 for (const auto& selection : group) { 123 if (selection.event_type_modifier.event_type.type == 124 PERF_TYPE_TRACEPOINT) { 125 result.push_back(&selection.event_type_modifier.event_type); 126 } 127 } 128 } 129 return result; 130 } 131 132 bool EventSelectionSet::HasInplaceSampler() const { 133 for (const auto& group : groups_) { 134 for (const auto& sel : group) { 135 if (sel.event_attr.type == SIMPLEPERF_TYPE_USER_SPACE_SAMPLERS && 136 sel.event_attr.config == SIMPLEPERF_CONFIG_INPLACE_SAMPLER) { 137 return true; 138 } 139 } 140 } 141 return false; 142 } 143 144 std::vector<EventAttrWithId> EventSelectionSet::GetEventAttrWithId() const { 145 std::vector<EventAttrWithId> result; 146 for (const auto& group : groups_) { 147 for (const auto& selection : group) { 148 EventAttrWithId attr_id; 149 attr_id.attr = &selection.event_attr; 150 for (const auto& fd : selection.event_fds) { 151 attr_id.ids.push_back(fd->Id()); 152 } 153 if (!selection.inplace_samplers.empty()) { 154 attr_id.ids.push_back(selection.inplace_samplers[0]->Id()); 155 } 156 result.push_back(attr_id); 157 } 158 } 159 return result; 160 } 161 162 // Union the sample type of different event attrs can make reading sample 163 // records in perf.data easier. 164 void EventSelectionSet::UnionSampleType() { 165 uint64_t sample_type = 0; 166 for (const auto& group : groups_) { 167 for (const auto& selection : group) { 168 sample_type |= selection.event_attr.sample_type; 169 } 170 } 171 for (auto& group : groups_) { 172 for (auto& selection : group) { 173 selection.event_attr.sample_type = sample_type; 174 } 175 } 176 } 177 178 void EventSelectionSet::SetEnableOnExec(bool enable) { 179 for (auto& group : groups_) { 180 for (auto& selection : group) { 181 // If sampling is enabled on exec, then it is disabled at startup, 182 // otherwise it should be enabled at startup. Don't use 183 // ioctl(PERF_EVENT_IOC_ENABLE) to enable it after perf_event_open(). 184 // Because some android kernels can't handle ioctl() well when cpu-hotplug 185 // happens. See http://b/25193162. 186 if (enable) { 187 selection.event_attr.enable_on_exec = 1; 188 selection.event_attr.disabled = 1; 189 } else { 190 selection.event_attr.enable_on_exec = 0; 191 selection.event_attr.disabled = 0; 192 } 193 } 194 } 195 } 196 197 bool EventSelectionSet::GetEnableOnExec() { 198 for (const auto& group : groups_) { 199 for (const auto& selection : group) { 200 if (selection.event_attr.enable_on_exec == 0) { 201 return false; 202 } 203 } 204 } 205 return true; 206 } 207 208 void EventSelectionSet::SampleIdAll() { 209 for (auto& group : groups_) { 210 for (auto& selection : group) { 211 selection.event_attr.sample_id_all = 1; 212 } 213 } 214 } 215 216 void EventSelectionSet::SetSampleFreq(uint64_t sample_freq) { 217 for (auto& group : groups_) { 218 for (auto& selection : group) { 219 selection.event_attr.freq = 1; 220 selection.event_attr.sample_freq = sample_freq; 221 } 222 } 223 } 224 225 void EventSelectionSet::SetSamplePeriod(uint64_t sample_period) { 226 for (auto& group : groups_) { 227 for (auto& selection : group) { 228 selection.event_attr.freq = 0; 229 selection.event_attr.sample_period = sample_period; 230 } 231 } 232 } 233 234 void EventSelectionSet::UseDefaultSampleFreq() { 235 for (auto& group : groups_) { 236 for (auto& selection : group) { 237 if (selection.event_type_modifier.event_type.type == 238 PERF_TYPE_TRACEPOINT) { 239 selection.event_attr.freq = 0; 240 selection.event_attr.sample_period = 241 DEFAULT_SAMPLE_PERIOD_FOR_TRACEPOINT_EVENT; 242 } else { 243 selection.event_attr.freq = 1; 244 selection.event_attr.sample_freq = 245 DEFAULT_SAMPLE_FREQ_FOR_NONTRACEPOINT_EVENT; 246 } 247 } 248 } 249 } 250 251 bool EventSelectionSet::SetBranchSampling(uint64_t branch_sample_type) { 252 if (branch_sample_type != 0 && 253 (branch_sample_type & 254 (PERF_SAMPLE_BRANCH_ANY | PERF_SAMPLE_BRANCH_ANY_CALL | 255 PERF_SAMPLE_BRANCH_ANY_RETURN | PERF_SAMPLE_BRANCH_IND_CALL)) == 0) { 256 LOG(ERROR) << "Invalid branch_sample_type: 0x" << std::hex 257 << branch_sample_type; 258 return false; 259 } 260 if (branch_sample_type != 0 && !IsBranchSamplingSupported()) { 261 LOG(ERROR) << "branch stack sampling is not supported on this device."; 262 return false; 263 } 264 for (auto& group : groups_) { 265 for (auto& selection : group) { 266 perf_event_attr& attr = selection.event_attr; 267 if (branch_sample_type != 0) { 268 attr.sample_type |= PERF_SAMPLE_BRANCH_STACK; 269 } else { 270 attr.sample_type &= ~PERF_SAMPLE_BRANCH_STACK; 271 } 272 attr.branch_sample_type = branch_sample_type; 273 } 274 } 275 return true; 276 } 277 278 void EventSelectionSet::EnableFpCallChainSampling() { 279 for (auto& group : groups_) { 280 for (auto& selection : group) { 281 selection.event_attr.sample_type |= PERF_SAMPLE_CALLCHAIN; 282 } 283 } 284 } 285 286 bool EventSelectionSet::EnableDwarfCallChainSampling(uint32_t dump_stack_size) { 287 if (!IsDwarfCallChainSamplingSupported()) { 288 LOG(ERROR) << "dwarf callchain sampling is not supported on this device."; 289 return false; 290 } 291 for (auto& group : groups_) { 292 for (auto& selection : group) { 293 selection.event_attr.sample_type |= PERF_SAMPLE_CALLCHAIN | 294 PERF_SAMPLE_REGS_USER | 295 PERF_SAMPLE_STACK_USER; 296 selection.event_attr.exclude_callchain_user = 1; 297 selection.event_attr.sample_regs_user = 298 GetSupportedRegMask(GetMachineArch()); 299 selection.event_attr.sample_stack_user = dump_stack_size; 300 } 301 } 302 return true; 303 } 304 305 void EventSelectionSet::SetInherit(bool enable) { 306 for (auto& group : groups_) { 307 for (auto& selection : group) { 308 selection.event_attr.inherit = (enable ? 1 : 0); 309 } 310 } 311 } 312 313 bool EventSelectionSet::NeedKernelSymbol() const { 314 for (const auto& group : groups_) { 315 for (const auto& selection : group) { 316 if (!selection.event_type_modifier.exclude_kernel) { 317 return true; 318 } 319 } 320 } 321 return false; 322 } 323 324 static bool CheckIfCpusOnline(const std::vector<int>& cpus) { 325 std::vector<int> online_cpus = GetOnlineCpus(); 326 for (const auto& cpu : cpus) { 327 if (std::find(online_cpus.begin(), online_cpus.end(), cpu) == 328 online_cpus.end()) { 329 LOG(ERROR) << "cpu " << cpu << " is not online."; 330 return false; 331 } 332 } 333 return true; 334 } 335 336 bool EventSelectionSet::OpenEventFilesOnGroup(EventSelectionGroup& group, 337 pid_t tid, int cpu, 338 std::string* failed_event_type) { 339 std::vector<std::unique_ptr<EventFd>> event_fds; 340 // Given a tid and cpu, events on the same group should be all opened 341 // successfully or all failed to open. 342 EventFd* group_fd = nullptr; 343 for (auto& selection : group) { 344 std::unique_ptr<EventFd> event_fd = 345 EventFd::OpenEventFile(selection.event_attr, tid, cpu, group_fd); 346 if (event_fd != nullptr) { 347 LOG(VERBOSE) << "OpenEventFile for " << event_fd->Name(); 348 event_fds.push_back(std::move(event_fd)); 349 } else { 350 if (failed_event_type != nullptr) { 351 *failed_event_type = selection.event_type_modifier.name; 352 return false; 353 } 354 } 355 if (group_fd == nullptr) { 356 group_fd = event_fd.get(); 357 } 358 } 359 for (size_t i = 0; i < group.size(); ++i) { 360 group[i].event_fds.push_back(std::move(event_fds[i])); 361 } 362 return true; 363 } 364 365 static std::map<pid_t, std::set<pid_t>> PrepareThreads(const std::set<pid_t>& processes, 366 const std::set<pid_t>& threads) { 367 std::map<pid_t, std::set<pid_t>> result; 368 for (auto& pid : processes) { 369 std::vector<pid_t> tids = GetThreadsInProcess(pid); 370 std::set<pid_t>& threads_in_process = result[pid]; 371 threads_in_process.insert(tids.begin(), tids.end()); 372 } 373 for (auto& tid : threads) { 374 // tid = -1 means monitoring all threads. 375 if (tid == -1) { 376 result[-1].insert(-1); 377 } else { 378 pid_t pid; 379 if (GetProcessForThread(tid, &pid)) { 380 result[pid].insert(tid); 381 } 382 } 383 } 384 return result; 385 } 386 387 bool EventSelectionSet::OpenEventFiles(const std::vector<int>& on_cpus) { 388 std::vector<int> cpus = on_cpus; 389 if (!cpus.empty()) { 390 // cpus = {-1} means open an event file for all cpus. 391 if (!(cpus.size() == 1 && cpus[0] == -1) && !CheckIfCpusOnline(cpus)) { 392 return false; 393 } 394 } else { 395 cpus = GetOnlineCpus(); 396 } 397 std::map<pid_t, std::set<pid_t>> process_map = PrepareThreads(processes_, threads_); 398 for (auto& group : groups_) { 399 if (IsUserSpaceSamplerGroup(group)) { 400 if (!OpenUserSpaceSamplersOnGroup(group, process_map)) { 401 return false; 402 } 403 } else { 404 for (const auto& pair : process_map) { 405 for (const auto& tid : pair.second) { 406 size_t success_cpu_count = 0; 407 std::string failed_event_type; 408 for (const auto& cpu : cpus) { 409 if (OpenEventFilesOnGroup(group, tid, cpu, &failed_event_type)) { 410 success_cpu_count++; 411 } 412 } 413 // As the online cpus can be enabled or disabled at runtime, we may not 414 // open event file for all cpus successfully. But we should open at 415 // least one cpu successfully. 416 if (success_cpu_count == 0) { 417 PLOG(ERROR) << "failed to open perf event file for event_type " 418 << failed_event_type << " for " 419 << (tid == -1 ? "all threads" : "thread " + std::to_string(tid)) 420 << " on all cpus"; 421 return false; 422 } 423 } 424 } 425 } 426 } 427 return true; 428 } 429 430 bool EventSelectionSet::IsUserSpaceSamplerGroup(EventSelectionGroup& group) { 431 return group.size() == 1 && group[0].event_attr.type == SIMPLEPERF_TYPE_USER_SPACE_SAMPLERS; 432 } 433 434 bool EventSelectionSet::OpenUserSpaceSamplersOnGroup(EventSelectionGroup& group, 435 const std::map<pid_t, std::set<pid_t>>& process_map) { 436 CHECK_EQ(group.size(), 1u); 437 for (auto& selection : group) { 438 if (selection.event_attr.type == SIMPLEPERF_TYPE_USER_SPACE_SAMPLERS && 439 selection.event_attr.config == SIMPLEPERF_CONFIG_INPLACE_SAMPLER) { 440 for (auto& pair : process_map) { 441 std::unique_ptr<InplaceSamplerClient> sampler = InplaceSamplerClient::Create( 442 selection.event_attr, pair.first, pair.second); 443 if (sampler == nullptr) { 444 return false; 445 } 446 selection.inplace_samplers.push_back(std::move(sampler)); 447 } 448 } 449 } 450 return true; 451 } 452 453 static bool ReadCounter(const EventFd* event_fd, CounterInfo* counter) { 454 if (!event_fd->ReadCounter(&counter->counter)) { 455 return false; 456 } 457 counter->tid = event_fd->ThreadId(); 458 counter->cpu = event_fd->Cpu(); 459 return true; 460 } 461 462 bool EventSelectionSet::ReadCounters(std::vector<CountersInfo>* counters) { 463 counters->clear(); 464 for (size_t i = 0; i < groups_.size(); ++i) { 465 for (auto& selection : groups_[i]) { 466 CountersInfo counters_info; 467 counters_info.group_id = i; 468 counters_info.event_name = selection.event_type_modifier.event_type.name; 469 counters_info.event_modifier = selection.event_type_modifier.modifier; 470 counters_info.counters = selection.hotplugged_counters; 471 for (auto& event_fd : selection.event_fds) { 472 CounterInfo counter; 473 if (!ReadCounter(event_fd.get(), &counter)) { 474 return false; 475 } 476 counters_info.counters.push_back(counter); 477 } 478 counters->push_back(counters_info); 479 } 480 } 481 return true; 482 } 483 484 bool EventSelectionSet::MmapEventFiles(size_t min_mmap_pages, 485 size_t max_mmap_pages) { 486 for (size_t i = max_mmap_pages; i >= min_mmap_pages; i >>= 1) { 487 if (MmapEventFiles(i, i == min_mmap_pages)) { 488 LOG(VERBOSE) << "Mapped buffer size is " << i << " pages."; 489 mmap_pages_ = i; 490 return true; 491 } 492 for (auto& group : groups_) { 493 for (auto& selection : group) { 494 for (auto& event_fd : selection.event_fds) { 495 event_fd->DestroyMappedBuffer(); 496 } 497 } 498 } 499 } 500 return false; 501 } 502 503 bool EventSelectionSet::MmapEventFiles(size_t mmap_pages, bool report_error) { 504 // Allocate a mapped buffer for each cpu. 505 std::map<int, EventFd*> cpu_map; 506 for (auto& group : groups_) { 507 for (auto& selection : group) { 508 for (auto& event_fd : selection.event_fds) { 509 auto it = cpu_map.find(event_fd->Cpu()); 510 if (it != cpu_map.end()) { 511 if (!event_fd->ShareMappedBuffer(*(it->second), report_error)) { 512 return false; 513 } 514 } else { 515 if (!event_fd->CreateMappedBuffer(mmap_pages, report_error)) { 516 return false; 517 } 518 cpu_map[event_fd->Cpu()] = event_fd.get(); 519 } 520 } 521 } 522 } 523 return true; 524 } 525 526 bool EventSelectionSet::PrepareToReadMmapEventData(const std::function<bool(Record*)>& callback) { 527 // Add read Events for perf event files having mapped buffer. 528 for (auto& group : groups_) { 529 for (auto& selection : group) { 530 for (auto& event_fd : selection.event_fds) { 531 if (event_fd->HasMappedBuffer()) { 532 if (!event_fd->StartPolling(*loop_, [this]() { 533 return ReadMmapEventData(); 534 })) { 535 return false; 536 } 537 } 538 } 539 for (auto& sampler : selection.inplace_samplers) { 540 if (!sampler->StartPolling(*loop_, callback, 541 [&] { return CheckMonitoredTargets(); })) { 542 return false; 543 } 544 } 545 } 546 } 547 548 // Prepare record callback function. 549 record_callback_ = callback; 550 return true; 551 } 552 553 // When reading from mmap buffers, we prefer reading from all buffers at once 554 // rather than reading one buffer at a time. Because by reading all buffers 555 // at once, we can merge records from different buffers easily in memory. 556 // Otherwise, we have to sort records with greater effort. 557 bool EventSelectionSet::ReadMmapEventData() { 558 size_t head_size = 0; 559 std::vector<RecordBufferHead>& heads = record_buffer_heads_; 560 if (heads.empty()) { 561 heads.resize(1); 562 } 563 heads[0].current_pos = 0; 564 size_t buffer_pos = 0; 565 566 for (auto& group : groups_) { 567 for (auto& selection : group) { 568 for (auto& event_fd : selection.event_fds) { 569 if (event_fd->HasMappedBuffer()) { 570 if (event_fd->GetAvailableMmapData(record_buffer_, buffer_pos) != 0) { 571 heads[head_size].end_pos = buffer_pos; 572 heads[head_size].attr = &selection.event_attr; 573 head_size++; 574 if (heads.size() == head_size) { 575 heads.resize(head_size + 1); 576 } 577 heads[head_size].current_pos = buffer_pos; 578 } 579 } 580 } 581 } 582 } 583 584 if (head_size == 0) { 585 return true; 586 } 587 if (head_size == 1) { 588 // Only one buffer has data, process it directly. 589 std::vector<std::unique_ptr<Record>> records = 590 ReadRecordsFromBuffer(*heads[0].attr, 591 record_buffer_.data(), buffer_pos); 592 for (auto& r : records) { 593 if (!record_callback_(r.get())) { 594 return false; 595 } 596 } 597 } else { 598 // Use a priority queue to merge records from different buffers. As 599 // records from the same buffer are already ordered by time, we only 600 // need to merge the first record from all buffers. And each time a 601 // record is popped from the queue, we put the next record from its 602 // buffer into the queue. 603 auto comparator = [&](RecordBufferHead* h1, RecordBufferHead* h2) { 604 return h1->timestamp > h2->timestamp; 605 }; 606 std::priority_queue<RecordBufferHead*, std::vector<RecordBufferHead*>, decltype(comparator)> q(comparator); 607 for (size_t i = 0; i < head_size; ++i) { 608 RecordBufferHead& h = heads[i]; 609 h.r = ReadRecordFromBuffer(*h.attr, &record_buffer_[h.current_pos]); 610 h.timestamp = h.r->Timestamp(); 611 h.current_pos += h.r->size(); 612 q.push(&h); 613 } 614 while (!q.empty()) { 615 RecordBufferHead* h = q.top(); 616 q.pop(); 617 if (!record_callback_(h->r.get())) { 618 return false; 619 } 620 if (h->current_pos < h->end_pos) { 621 h->r = ReadRecordFromBuffer(*h->attr, &record_buffer_[h->current_pos]); 622 h->timestamp = h->r->Timestamp(); 623 h->current_pos += h->r->size(); 624 q.push(h); 625 } 626 } 627 } 628 return true; 629 } 630 631 bool EventSelectionSet::FinishReadMmapEventData() { 632 if (!ReadMmapEventData()) { 633 return false; 634 } 635 if (!HasInplaceSampler()) { 636 return true; 637 } 638 // Inplace sampler server uses a buffer to cache samples before sending them, so we need to 639 // explicitly ask it to send the cached samples. 640 loop_.reset(new IOEventLoop); 641 size_t inplace_sampler_count = 0; 642 auto close_callback = [&]() { 643 if (--inplace_sampler_count == 0) { 644 return loop_->ExitLoop(); 645 } 646 return true; 647 }; 648 for (auto& group : groups_) { 649 for (auto& sel : group) { 650 for (auto& sampler : sel.inplace_samplers) { 651 if (!sampler->IsClosed()) { 652 if (!sampler->StopProfiling(*loop_, close_callback)) { 653 return false; 654 } 655 inplace_sampler_count++; 656 } 657 } 658 } 659 } 660 if (inplace_sampler_count == 0) { 661 return true; 662 } 663 664 // Set a timeout to exit the loop. 665 timeval tv; 666 tv.tv_sec = 1; 667 tv.tv_usec = 0; 668 if (!loop_->AddPeriodicEvent(tv, [&]() { return loop_->ExitLoop(); })) { 669 return false; 670 } 671 return loop_->RunLoop(); 672 } 673 674 bool EventSelectionSet::HandleCpuHotplugEvents(const std::vector<int>& monitored_cpus, 675 double check_interval_in_sec) { 676 monitored_cpus_.insert(monitored_cpus.begin(), monitored_cpus.end()); 677 online_cpus_ = GetOnlineCpus(); 678 if (!loop_->AddPeriodicEvent(SecondToTimeval(check_interval_in_sec), 679 [&]() { return DetectCpuHotplugEvents(); })) { 680 return false; 681 } 682 return true; 683 } 684 685 bool EventSelectionSet::DetectCpuHotplugEvents() { 686 std::vector<int> new_cpus = GetOnlineCpus(); 687 for (const auto& cpu : online_cpus_) { 688 if (std::find(new_cpus.begin(), new_cpus.end(), cpu) == new_cpus.end()) { 689 if (monitored_cpus_.empty() || 690 monitored_cpus_.find(cpu) != monitored_cpus_.end()) { 691 LOG(INFO) << "Cpu " << cpu << " is offlined"; 692 if (!HandleCpuOfflineEvent(cpu)) { 693 return false; 694 } 695 } 696 } 697 } 698 for (const auto& cpu : new_cpus) { 699 if (std::find(online_cpus_.begin(), online_cpus_.end(), cpu) == 700 online_cpus_.end()) { 701 if (monitored_cpus_.empty() || 702 monitored_cpus_.find(cpu) != monitored_cpus_.end()) { 703 LOG(INFO) << "Cpu " << cpu << " is onlined"; 704 if (!HandleCpuOnlineEvent(cpu)) { 705 return false; 706 } 707 } 708 } 709 } 710 online_cpus_ = new_cpus; 711 return true; 712 } 713 714 bool EventSelectionSet::HandleCpuOfflineEvent(int cpu) { 715 if (!for_stat_cmd_) { 716 // Read mmap data here, so we won't lose the existing records of the 717 // offlined cpu. 718 if (!ReadMmapEventData()) { 719 return false; 720 } 721 } 722 for (auto& group : groups_) { 723 for (auto& selection : group) { 724 for (auto it = selection.event_fds.begin(); 725 it != selection.event_fds.end();) { 726 if ((*it)->Cpu() == cpu) { 727 if (for_stat_cmd_) { 728 CounterInfo counter; 729 if (!ReadCounter(it->get(), &counter)) { 730 return false; 731 } 732 selection.hotplugged_counters.push_back(counter); 733 } else { 734 if ((*it)->HasMappedBuffer()) { 735 if (!(*it)->StopPolling()) { 736 return false; 737 } 738 } 739 } 740 it = selection.event_fds.erase(it); 741 } else { 742 ++it; 743 } 744 } 745 } 746 } 747 return true; 748 } 749 750 bool EventSelectionSet::HandleCpuOnlineEvent(int cpu) { 751 // We need to start profiling when opening new event files. 752 SetEnableOnExec(false); 753 std::map<pid_t, std::set<pid_t>> process_map = PrepareThreads(processes_, threads_); 754 for (auto& group : groups_) { 755 if (IsUserSpaceSamplerGroup(group)) { 756 continue; 757 } 758 for (const auto& pair : process_map) { 759 for (const auto& tid : pair.second) { 760 std::string failed_event_type; 761 if (!OpenEventFilesOnGroup(group, tid, cpu, &failed_event_type)) { 762 // If failed to open event files, maybe the cpu has been offlined. 763 PLOG(WARNING) << "failed to open perf event file for event_type " 764 << failed_event_type << " for " 765 << (tid == -1 ? "all threads" : "thread " + std::to_string(tid)) 766 << " on cpu " << cpu; 767 } 768 } 769 } 770 } 771 if (!for_stat_cmd_) { 772 // Prepare mapped buffer. 773 if (!CreateMappedBufferForCpu(cpu)) { 774 return false; 775 } 776 // Send a EventIdRecord. 777 std::vector<uint64_t> event_id_data; 778 uint64_t attr_id = 0; 779 for (const auto& group : groups_) { 780 for (const auto& selection : group) { 781 for (const auto& event_fd : selection.event_fds) { 782 if (event_fd->Cpu() == cpu) { 783 event_id_data.push_back(attr_id); 784 event_id_data.push_back(event_fd->Id()); 785 } 786 } 787 ++attr_id; 788 } 789 } 790 EventIdRecord r(event_id_data); 791 if (!record_callback_(&r)) { 792 return false; 793 } 794 } 795 return true; 796 } 797 798 bool EventSelectionSet::CreateMappedBufferForCpu(int cpu) { 799 EventFd* fd_with_buffer = nullptr; 800 for (auto& group : groups_) { 801 for (auto& selection : group) { 802 for (auto& event_fd : selection.event_fds) { 803 if (event_fd->Cpu() != cpu) { 804 continue; 805 } 806 if (fd_with_buffer == nullptr) { 807 if (!event_fd->CreateMappedBuffer(mmap_pages_, true)) { 808 return false; 809 } 810 fd_with_buffer = event_fd.get(); 811 } else { 812 if (!event_fd->ShareMappedBuffer(*fd_with_buffer, true)) { 813 fd_with_buffer->DestroyMappedBuffer(); 814 return false; 815 } 816 } 817 } 818 } 819 } 820 if (fd_with_buffer != nullptr && 821 !fd_with_buffer->StartPolling(*loop_, [this]() { 822 return ReadMmapEventData(); 823 })) { 824 return false; 825 } 826 return true; 827 } 828 829 bool EventSelectionSet::StopWhenNoMoreTargets(double check_interval_in_sec) { 830 return loop_->AddPeriodicEvent(SecondToTimeval(check_interval_in_sec), 831 [&]() { return CheckMonitoredTargets(); }); 832 } 833 834 bool EventSelectionSet::CheckMonitoredTargets() { 835 if (!HasSampler()) { 836 return loop_->ExitLoop(); 837 } 838 for (const auto& tid : threads_) { 839 if (IsThreadAlive(tid)) { 840 return true; 841 } 842 } 843 for (const auto& pid : processes_) { 844 if (IsThreadAlive(pid)) { 845 return true; 846 } 847 } 848 return loop_->ExitLoop(); 849 } 850 851 bool EventSelectionSet::HasSampler() { 852 for (auto& group : groups_) { 853 for (auto& sel : group) { 854 if (!sel.event_fds.empty()) { 855 return true; 856 } 857 for (auto& sampler : sel.inplace_samplers) { 858 if (!sampler->IsClosed()) { 859 return true; 860 } 861 } 862 } 863 } 864 return false; 865 } 866