/* * Copyright (C) 2015 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "profile_saver.h" #include <sys/resource.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include "android-base/strings.h" #include "art_method-inl.h" #include "base/enums.h" #include "base/systrace.h" #include "base/time_utils.h" #include "compiler_filter.h" #include "gc/collector_type.h" #include "gc/gc_cause.h" #include "gc/scoped_gc_critical_section.h" #include "oat_file_manager.h" #include "scoped_thread_state_change-inl.h" namespace art { ProfileSaver* ProfileSaver::instance_ = nullptr; pthread_t ProfileSaver::profiler_pthread_ = 0U; ProfileSaver::ProfileSaver(const ProfileSaverOptions& options, const std::string& output_filename, jit::JitCodeCache* jit_code_cache, const std::vector<std::string>& code_paths) : jit_code_cache_(jit_code_cache), shutting_down_(false), last_time_ns_saver_woke_up_(0), jit_activity_notifications_(0), wait_lock_("ProfileSaver wait lock"), period_condition_("ProfileSaver period condition", wait_lock_), total_bytes_written_(0), total_number_of_writes_(0), total_number_of_code_cache_queries_(0), total_number_of_skipped_writes_(0), total_number_of_failed_writes_(0), total_ms_of_sleep_(0), total_ns_of_work_(0), max_number_of_profile_entries_cached_(0), total_number_of_hot_spikes_(0), total_number_of_wake_ups_(0), options_(options) { DCHECK(options_.IsEnabled()); AddTrackedLocations(output_filename, code_paths); } ProfileSaver::~ProfileSaver() { for (auto& it : profile_cache_) { delete it.second; } } void ProfileSaver::Run() { Thread* self = Thread::Current(); // Fetch the resolved classes for the app images after sleeping for // options_.GetSaveResolvedClassesDelayMs(). // TODO(calin) This only considers the case of the primary profile file. // Anything that gets loaded in the same VM will not have their resolved // classes save (unless they started before the initial saving was done). { MutexLock mu(self, wait_lock_); const uint64_t end_time = NanoTime() + MsToNs(options_.GetSaveResolvedClassesDelayMs()); while (true) { const uint64_t current_time = NanoTime(); if (current_time >= end_time) { break; } period_condition_.TimedWait(self, NsToMs(end_time - current_time), 0); } total_ms_of_sleep_ += options_.GetSaveResolvedClassesDelayMs(); } FetchAndCacheResolvedClassesAndMethods(); // Loop for the profiled methods. while (!ShuttingDown(self)) { uint64_t sleep_start = NanoTime(); { uint64_t sleep_time = 0; { MutexLock mu(self, wait_lock_); period_condition_.Wait(self); sleep_time = NanoTime() - sleep_start; } // Check if the thread was woken up for shutdown. if (ShuttingDown(self)) { break; } total_number_of_wake_ups_++; // We might have been woken up by a huge number of notifications to guarantee saving. // If we didn't meet the minimum saving period go back to sleep (only if missed by // a reasonable margin). uint64_t min_save_period_ns = MsToNs(options_.GetMinSavePeriodMs()); while (min_save_period_ns * 0.9 > sleep_time) { { MutexLock mu(self, wait_lock_); period_condition_.TimedWait(self, NsToMs(min_save_period_ns - sleep_time), 0); sleep_time = NanoTime() - sleep_start; } // Check if the thread was woken up for shutdown. if (ShuttingDown(self)) { break; } total_number_of_wake_ups_++; } } total_ms_of_sleep_ += NsToMs(NanoTime() - sleep_start); if (ShuttingDown(self)) { break; } uint16_t number_of_new_methods = 0; uint64_t start_work = NanoTime(); bool profile_saved_to_disk = ProcessProfilingInfo(/*force_save*/false, &number_of_new_methods); // Update the notification counter based on result. Note that there might be contention on this // but we don't care about to be 100% precise. if (!profile_saved_to_disk) { // If we didn't save to disk it may be because we didn't have enough new methods. // Set the jit activity notifications to number_of_new_methods so we can wake up earlier // if needed. jit_activity_notifications_ = number_of_new_methods; } total_ns_of_work_ += NanoTime() - start_work; } } void ProfileSaver::NotifyJitActivity() { MutexLock mu(Thread::Current(), *Locks::profiler_lock_); if (instance_ == nullptr || instance_->shutting_down_) { return; } instance_->NotifyJitActivityInternal(); } void ProfileSaver::WakeUpSaver() { jit_activity_notifications_ = 0; last_time_ns_saver_woke_up_ = NanoTime(); period_condition_.Signal(Thread::Current()); } void ProfileSaver::NotifyJitActivityInternal() { // Unlikely to overflow but if it happens, // we would have waken up the saver long before that. jit_activity_notifications_++; // Note that we are not as precise as we could be here but we don't want to wake the saver // every time we see a hot method. if (jit_activity_notifications_ > options_.GetMinNotificationBeforeWake()) { MutexLock wait_mutex(Thread::Current(), wait_lock_); if ((NanoTime() - last_time_ns_saver_woke_up_) > MsToNs(options_.GetMinSavePeriodMs())) { WakeUpSaver(); } else if (jit_activity_notifications_ > options_.GetMaxNotificationBeforeWake()) { // Make sure to wake up the saver if we see a spike in the number of notifications. // This is a precaution to avoid losing a big number of methods in case // this is a spike with no jit after. total_number_of_hot_spikes_++; WakeUpSaver(); } } } // Get resolved methods that have a profile info or more than kStartupMethodSamples samples. // Excludes native methods and classes in the boot image. class GetMethodsVisitor : public ClassVisitor { public: GetMethodsVisitor(std::vector<MethodReference>* methods, uint32_t startup_method_samples) : methods_(methods), startup_method_samples_(startup_method_samples) {} virtual bool operator()(ObjPtr<mirror::Class> klass) REQUIRES_SHARED(Locks::mutator_lock_) { if (Runtime::Current()->GetHeap()->ObjectIsInBootImageSpace(klass) || !klass->IsResolved() || klass->IsErroneousResolved()) { return true; } for (ArtMethod& method : klass->GetMethods(kRuntimePointerSize)) { if (!method.IsNative()) { if (method.GetCounter() >= startup_method_samples_ || method.GetProfilingInfo(kRuntimePointerSize) != nullptr) { // Have samples, add to profile. const DexFile* dex_file = method.GetInterfaceMethodIfProxy(kRuntimePointerSize)->GetDexFile(); methods_->push_back(MethodReference(dex_file, method.GetDexMethodIndex())); } } } return true; } private: std::vector<MethodReference>* const methods_; uint32_t startup_method_samples_; }; void ProfileSaver::FetchAndCacheResolvedClassesAndMethods() { ScopedTrace trace(__PRETTY_FUNCTION__); // Resolve any new registered locations. ResolveTrackedLocations(); Thread* const self = Thread::Current(); std::vector<MethodReference> methods; std::set<DexCacheResolvedClasses> resolved_classes; { ScopedObjectAccess soa(self); gc::ScopedGCCriticalSection sgcs(self, gc::kGcCauseProfileSaver, gc::kCollectorTypeCriticalSection); ClassLinker* const class_linker = Runtime::Current()->GetClassLinker(); resolved_classes = class_linker->GetResolvedClasses(/*ignore boot classes*/ true); { ScopedTrace trace2("Get hot methods"); GetMethodsVisitor visitor(&methods, options_.GetStartupMethodSamples()); class_linker->VisitClasses(&visitor); VLOG(profiler) << "Methods with samples greater than " << options_.GetStartupMethodSamples() << " = " << methods.size(); } } MutexLock mu(self, *Locks::profiler_lock_); uint64_t total_number_of_profile_entries_cached = 0; for (const auto& it : tracked_dex_base_locations_) { std::set<DexCacheResolvedClasses> resolved_classes_for_location; const std::string& filename = it.first; const std::set<std::string>& locations = it.second; std::vector<ProfileMethodInfo> profile_methods_for_location; for (const MethodReference& ref : methods) { if (locations.find(ref.dex_file->GetBaseLocation()) != locations.end()) { profile_methods_for_location.emplace_back(ref.dex_file, ref.dex_method_index); } } for (const DexCacheResolvedClasses& classes : resolved_classes) { if (locations.find(classes.GetBaseLocation()) != locations.end()) { VLOG(profiler) << "Added " << classes.GetClasses().size() << " classes for location " << classes.GetBaseLocation() << " (" << classes.GetDexLocation() << ")"; resolved_classes_for_location.insert(classes); } else { VLOG(profiler) << "Location not found " << classes.GetBaseLocation() << " (" << classes.GetDexLocation() << ")"; } } auto info_it = profile_cache_.Put( filename, new ProfileCompilationInfo(Runtime::Current()->GetArenaPool())); ProfileCompilationInfo* cached_info = info_it->second; cached_info->AddMethodsAndClasses(profile_methods_for_location, resolved_classes_for_location); total_number_of_profile_entries_cached += resolved_classes_for_location.size(); } max_number_of_profile_entries_cached_ = std::max( max_number_of_profile_entries_cached_, total_number_of_profile_entries_cached); } bool ProfileSaver::ProcessProfilingInfo(bool force_save, /*out*/uint16_t* number_of_new_methods) { ScopedTrace trace(__PRETTY_FUNCTION__); // Resolve any new registered locations. ResolveTrackedLocations(); SafeMap<std::string, std::set<std::string>> tracked_locations; { // Make a copy so that we don't hold the lock while doing I/O. MutexLock mu(Thread::Current(), *Locks::profiler_lock_); tracked_locations = tracked_dex_base_locations_; } bool profile_file_saved = false; if (number_of_new_methods != nullptr) { *number_of_new_methods = 0; } for (const auto& it : tracked_locations) { if (!force_save && ShuttingDown(Thread::Current())) { // The ProfileSaver is in shutdown mode, meaning a stop request was made and // we need to exit cleanly (by waiting for the saver thread to finish). Unless // we have a request for a forced save, do not do any processing so that we // speed up the exit. return true; } const std::string& filename = it.first; const std::set<std::string>& locations = it.second; std::vector<ProfileMethodInfo> profile_methods; { ScopedObjectAccess soa(Thread::Current()); jit_code_cache_->GetProfiledMethods(locations, profile_methods); total_number_of_code_cache_queries_++; } { ProfileCompilationInfo info(Runtime::Current()->GetArenaPool()); if (!info.Load(filename, /*clear_if_invalid*/ true)) { LOG(WARNING) << "Could not forcefully load profile " << filename; continue; } uint64_t last_save_number_of_methods = info.GetNumberOfMethods(); uint64_t last_save_number_of_classes = info.GetNumberOfResolvedClasses(); info.AddMethodsAndClasses(profile_methods, std::set<DexCacheResolvedClasses>()); auto profile_cache_it = profile_cache_.find(filename); if (profile_cache_it != profile_cache_.end()) { info.MergeWith(*(profile_cache_it->second)); } int64_t delta_number_of_methods = info.GetNumberOfMethods() - last_save_number_of_methods; int64_t delta_number_of_classes = info.GetNumberOfResolvedClasses() - last_save_number_of_classes; if (!force_save && delta_number_of_methods < options_.GetMinMethodsToSave() && delta_number_of_classes < options_.GetMinClassesToSave()) { VLOG(profiler) << "Not enough information to save to: " << filename << " Number of methods: " << delta_number_of_methods << " Number of classes: " << delta_number_of_classes; total_number_of_skipped_writes_++; continue; } if (number_of_new_methods != nullptr) { *number_of_new_methods = std::max(static_cast<uint16_t>(delta_number_of_methods), *number_of_new_methods); } uint64_t bytes_written; // Force the save. In case the profile data is corrupted or the the profile // has the wrong version this will "fix" the file to the correct format. if (info.Save(filename, &bytes_written)) { // We managed to save the profile. Clear the cache stored during startup. if (profile_cache_it != profile_cache_.end()) { ProfileCompilationInfo *cached_info = profile_cache_it->second; profile_cache_.erase(profile_cache_it); delete cached_info; } if (bytes_written > 0) { total_number_of_writes_++; total_bytes_written_ += bytes_written; profile_file_saved = true; } else { // At this point we could still have avoided the write. // We load and merge the data from the file lazily at its first ever // save attempt. So, whatever we are trying to save could already be // in the file. total_number_of_skipped_writes_++; } } else { LOG(WARNING) << "Could not save profiling info to " << filename; total_number_of_failed_writes_++; } } // Trim the maps to madvise the pages used for profile info. // It is unlikely we will need them again in the near feature. Runtime::Current()->GetArenaPool()->TrimMaps(); } return profile_file_saved; } void* ProfileSaver::RunProfileSaverThread(void* arg) { Runtime* runtime = Runtime::Current(); bool attached = runtime->AttachCurrentThread("Profile Saver", /*as_daemon*/true, runtime->GetSystemThreadGroup(), /*create_peer*/true); if (!attached) { CHECK(runtime->IsShuttingDown(Thread::Current())); return nullptr; } ProfileSaver* profile_saver = reinterpret_cast<ProfileSaver*>(arg); profile_saver->Run(); runtime->DetachCurrentThread(); VLOG(profiler) << "Profile saver shutdown"; return nullptr; } static bool ShouldProfileLocation(const std::string& location) { OatFileManager& oat_manager = Runtime::Current()->GetOatFileManager(); const OatFile* oat_file = oat_manager.FindOpenedOatFileFromDexLocation(location); if (oat_file == nullptr) { // This can happen if we fallback to run code directly from the APK. // Profile it with the hope that the background dexopt will get us back into // a good state. VLOG(profiler) << "Asked to profile a location without an oat file:" << location; return true; } CompilerFilter::Filter filter = oat_file->GetCompilerFilter(); if ((filter == CompilerFilter::kSpeed) || (filter == CompilerFilter::kEverything)) { VLOG(profiler) << "Skip profiling oat file because it's already speed|everything compiled: " << location << " oat location: " << oat_file->GetLocation(); return false; } return true; } void ProfileSaver::Start(const ProfileSaverOptions& options, const std::string& output_filename, jit::JitCodeCache* jit_code_cache, const std::vector<std::string>& code_paths) { DCHECK(options.IsEnabled()); DCHECK(Runtime::Current()->GetJit() != nullptr); DCHECK(!output_filename.empty()); DCHECK(jit_code_cache != nullptr); std::vector<std::string> code_paths_to_profile; for (const std::string& location : code_paths) { if (ShouldProfileLocation(location)) { code_paths_to_profile.push_back(location); } } if (code_paths_to_profile.empty()) { VLOG(profiler) << "No code paths should be profiled."; return; } MutexLock mu(Thread::Current(), *Locks::profiler_lock_); if (instance_ != nullptr) { // If we already have an instance, make sure it uses the same jit_code_cache. // This may be called multiple times via Runtime::registerAppInfo (e.g. for // apps which share the same runtime). DCHECK_EQ(instance_->jit_code_cache_, jit_code_cache); // Add the code_paths to the tracked locations. instance_->AddTrackedLocations(output_filename, code_paths_to_profile); return; } VLOG(profiler) << "Starting profile saver using output file: " << output_filename << ". Tracking: " << android::base::Join(code_paths_to_profile, ':'); instance_ = new ProfileSaver(options, output_filename, jit_code_cache, code_paths_to_profile); // Create a new thread which does the saving. CHECK_PTHREAD_CALL( pthread_create, (&profiler_pthread_, nullptr, &RunProfileSaverThread, reinterpret_cast<void*>(instance_)), "Profile saver thread"); #if defined(ART_TARGET_ANDROID) // At what priority to schedule the saver threads. 9 is the lowest foreground priority on device. static constexpr int kProfileSaverPthreadPriority = 9; int result = setpriority( PRIO_PROCESS, pthread_gettid_np(profiler_pthread_), kProfileSaverPthreadPriority); if (result != 0) { PLOG(ERROR) << "Failed to setpriority to :" << kProfileSaverPthreadPriority; } #endif } void ProfileSaver::Stop(bool dump_info) { ProfileSaver* profile_saver = nullptr; pthread_t profiler_pthread = 0U; { MutexLock profiler_mutex(Thread::Current(), *Locks::profiler_lock_); VLOG(profiler) << "Stopping profile saver thread"; profile_saver = instance_; profiler_pthread = profiler_pthread_; if (instance_ == nullptr) { DCHECK(false) << "Tried to stop a profile saver which was not started"; return; } if (instance_->shutting_down_) { DCHECK(false) << "Tried to stop the profile saver twice"; return; } instance_->shutting_down_ = true; } { // Wake up the saver thread if it is sleeping to allow for a clean exit. MutexLock wait_mutex(Thread::Current(), profile_saver->wait_lock_); profile_saver->period_condition_.Signal(Thread::Current()); } // Wait for the saver thread to stop. CHECK_PTHREAD_CALL(pthread_join, (profiler_pthread, nullptr), "profile saver thread shutdown"); // Force save everything before destroying the instance. instance_->ProcessProfilingInfo(/*force_save*/true, /*number_of_new_methods*/nullptr); { MutexLock profiler_mutex(Thread::Current(), *Locks::profiler_lock_); if (dump_info) { instance_->DumpInfo(LOG_STREAM(INFO)); } instance_ = nullptr; profiler_pthread_ = 0U; } delete profile_saver; } bool ProfileSaver::ShuttingDown(Thread* self) { MutexLock mu(self, *Locks::profiler_lock_); return shutting_down_; } bool ProfileSaver::IsStarted() { MutexLock mu(Thread::Current(), *Locks::profiler_lock_); return instance_ != nullptr; } static void AddTrackedLocationsToMap(const std::string& output_filename, const std::vector<std::string>& code_paths, SafeMap<std::string, std::set<std::string>>* map) { auto it = map->find(output_filename); if (it == map->end()) { map->Put(output_filename, std::set<std::string>(code_paths.begin(), code_paths.end())); } else { it->second.insert(code_paths.begin(), code_paths.end()); } } void ProfileSaver::AddTrackedLocations(const std::string& output_filename, const std::vector<std::string>& code_paths) { // Add the code paths to the list of tracked location. AddTrackedLocationsToMap(output_filename, code_paths, &tracked_dex_base_locations_); // The code paths may contain symlinks which could fool the profiler. // If the dex file is compiled with an absolute location but loaded with symlink // the profiler could skip the dex due to location mismatch. // To avoid this, we add the code paths to the temporary cache of 'to_be_resolved' // locations. When the profiler thread executes we will resolve the paths to their // real paths. // Note that we delay taking the realpath to avoid spending more time than needed // when registering location (as it is done during app launch). AddTrackedLocationsToMap(output_filename, code_paths, &tracked_dex_base_locations_to_be_resolved_); } void ProfileSaver::DumpInstanceInfo(std::ostream& os) { MutexLock mu(Thread::Current(), *Locks::profiler_lock_); if (instance_ != nullptr) { instance_->DumpInfo(os); } } void ProfileSaver::DumpInfo(std::ostream& os) { os << "ProfileSaver total_bytes_written=" << total_bytes_written_ << '\n' << "ProfileSaver total_number_of_writes=" << total_number_of_writes_ << '\n' << "ProfileSaver total_number_of_code_cache_queries=" << total_number_of_code_cache_queries_ << '\n' << "ProfileSaver total_number_of_skipped_writes=" << total_number_of_skipped_writes_ << '\n' << "ProfileSaver total_number_of_failed_writes=" << total_number_of_failed_writes_ << '\n' << "ProfileSaver total_ms_of_sleep=" << total_ms_of_sleep_ << '\n' << "ProfileSaver total_ms_of_work=" << NsToMs(total_ns_of_work_) << '\n' << "ProfileSaver max_number_profile_entries_cached=" << max_number_of_profile_entries_cached_ << '\n' << "ProfileSaver total_number_of_hot_spikes=" << total_number_of_hot_spikes_ << '\n' << "ProfileSaver total_number_of_wake_ups=" << total_number_of_wake_ups_ << '\n'; } void ProfileSaver::ForceProcessProfiles() { ProfileSaver* saver = nullptr; { MutexLock mu(Thread::Current(), *Locks::profiler_lock_); saver = instance_; } // TODO(calin): this is not actually thread safe as the instance_ may have been deleted, // but we only use this in testing when we now this won't happen. // Refactor the way we handle the instance so that we don't end up in this situation. if (saver != nullptr) { saver->ProcessProfilingInfo(/*force_save*/true, /*number_of_new_methods*/nullptr); } } bool ProfileSaver::HasSeenMethod(const std::string& profile, const DexFile* dex_file, uint16_t method_idx) { MutexLock mu(Thread::Current(), *Locks::profiler_lock_); if (instance_ != nullptr) { ProfileCompilationInfo info(Runtime::Current()->GetArenaPool()); if (!info.Load(profile, /*clear_if_invalid*/false)) { return false; } return info.ContainsMethod(MethodReference(dex_file, method_idx)); } return false; } void ProfileSaver::ResolveTrackedLocations() { SafeMap<std::string, std::set<std::string>> locations_to_be_resolved; { // Make a copy so that we don't hold the lock while doing I/O. MutexLock mu(Thread::Current(), *Locks::profiler_lock_); locations_to_be_resolved = tracked_dex_base_locations_to_be_resolved_; tracked_dex_base_locations_to_be_resolved_.clear(); } // Resolve the locations. SafeMap<std::string, std::vector<std::string>> resolved_locations_map; for (const auto& it : locations_to_be_resolved) { const std::string& filename = it.first; const std::set<std::string>& locations = it.second; auto resolved_locations_it = resolved_locations_map.Put( filename, std::vector<std::string>(locations.size())); for (const auto& location : locations) { UniqueCPtr<const char[]> location_real(realpath(location.c_str(), nullptr)); // Note that it's ok if we cannot get the real path. if (location_real != nullptr) { resolved_locations_it->second.emplace_back(location_real.get()); } } } // Add the resolved locations to the tracked collection. MutexLock mu(Thread::Current(), *Locks::profiler_lock_); for (const auto& it : resolved_locations_map) { AddTrackedLocationsToMap(it.first, it.second, &tracked_dex_base_locations_); } } } // namespace art