From 6d72bf47606c2a288b911d682fd96129c9c1466d Mon Sep 17 00:00:00 2001 From: Lang Hames Date: Thu, 9 Jan 2025 16:37:35 +1100 Subject: [PATCH] [ORC][llvm-jitlink] Add SimpleLazyReexportsSpeculator, use in llvm-jitlink. Also adds a new IdleTask type and updates DynamicThreadPoolTaskDispatcher to schedule IdleTasks whenever the total number of threads running is less than the maximum number of MaterializationThreads. A SimpleLazyReexportsSpeculator instance maintains a list of speculation suggestions ((JITDylib, Function) pairs) and registered lazy reexports. When speculation opportunities are available (having been added via addSpeculationSuggestions or when lazy reexports were created) it schedules an IdleTask that triggers the next speculative lookup as soon as resources are available. Speculation suggestions are processed first, followed by lookups for lazy reexport bodies. A callback can be registered at object construction time to record lazy reexport executions as they happen, and these executions can be fed back into the speculator as suggestions on subsequent executions. The llvm-jitlink tool is updated to support speculation when lazy linking is used via three new arguments: -speculate=[none|simple] : When the 'simple' value is specified a SimpleLazyReexportsSpeculator instances is used for speculation. -speculate-order : Specifies a path to a CSV containing (jit dylib name, function name) triples to use as speculative suggestions in the current run. -record-lazy-execs : Specifies a path in which to record lazy function executions as a CSV of (jit dylib name, function name) pairs, suitable for use with -speculate-order. The same path can be passed to -speculate-order and -record-lazy-execs, in which case the file will be overwritten at the end of the execution. No testcase yet: Speculative linking is difficult to test (since by definition execution behavior should be unaffected by speculation) and this is an new prototype of the concept*. Tests will be added in the future once the interface and behavior settle down. * An earlier implementation of the speculation concept can be found in llvm/include/llvm/ExecutionEngine/Orc/Speculation.h. Both systems have the same goal (hiding compilation latency) but different mechanisms. This patch relies entirely on information available in the controller, where the old system could receive additional information from the JIT'd runtime via callbacks. I aim to combine the two in the future, but want to gain more practical experience with speculation first. --- .../Orc/JITLinkReentryTrampolines.h | 3 +- .../llvm/ExecutionEngine/Orc/LazyReexports.h | 102 +++++++- .../llvm/ExecutionEngine/Orc/TaskDispatch.h | 15 ++ .../Orc/JITLinkReentryTrampolines.cpp | 5 +- .../lib/ExecutionEngine/Orc/LazyReexports.cpp | 225 ++++++++++++++++-- llvm/lib/ExecutionEngine/Orc/TaskDispatch.cpp | 61 +++-- llvm/tools/llvm-jitlink/llvm-jitlink.cpp | 150 +++++++++++- llvm/tools/llvm-jitlink/llvm-jitlink.h | 13 +- 8 files changed, 509 insertions(+), 65 deletions(-) diff --git a/llvm/include/llvm/ExecutionEngine/Orc/JITLinkReentryTrampolines.h b/llvm/include/llvm/ExecutionEngine/Orc/JITLinkReentryTrampolines.h index 673019b748b3b..94d2ff0717eb4 100644 --- a/llvm/include/llvm/ExecutionEngine/Orc/JITLinkReentryTrampolines.h +++ b/llvm/include/llvm/ExecutionEngine/Orc/JITLinkReentryTrampolines.h @@ -65,7 +65,8 @@ class JITLinkReentryTrampolines { Expected> createJITLinkLazyReexportsManager(ObjectLinkingLayer &ObjLinkingLayer, RedirectableSymbolManager &RSMgr, - JITDylib &PlatformJD); + JITDylib &PlatformJD, + LazyReexportsManager::Listener *L = nullptr); } // namespace llvm::orc diff --git a/llvm/include/llvm/ExecutionEngine/Orc/LazyReexports.h b/llvm/include/llvm/ExecutionEngine/Orc/LazyReexports.h index c6b5d08544b1e..5111f8283d190 100644 --- a/llvm/include/llvm/ExecutionEngine/Orc/LazyReexports.h +++ b/llvm/include/llvm/ExecutionEngine/Orc/LazyReexports.h @@ -179,6 +179,37 @@ class LazyReexportsManager : public ResourceManager { lazyReexports(LazyReexportsManager &, SymbolAliasMap); public: + struct CallThroughInfo { + JITDylibSP JD; + SymbolStringPtr Name; + SymbolStringPtr BodyName; + }; + + class Listener { + public: + using CallThroughInfo = LazyReexportsManager::CallThroughInfo; + + virtual ~Listener(); + + /// Called under the session lock when new lazy reexports are created. + virtual void onLazyReexportsCreated(JITDylib &JD, ResourceKey K, + const SymbolAliasMap &Reexports) = 0; + + /// Called under the session lock when lazy reexports have their ownership + /// transferred to a new ResourceKey. + virtual void onLazyReexportsTransfered(JITDylib &JD, ResourceKey DstK, + ResourceKey SrcK) = 0; + + /// Called under the session lock when lazy reexports are removed. + virtual Error onLazyReexportsRemoved(JITDylib &JD, ResourceKey K) = 0; + + /// Called outside the session lock when a lazy reexport is called. + /// NOTE: Since this is called outside the session lock there is a chance + /// that the reexport referred to has already been removed. Listeners + /// must be prepared to handle requests for stale reexports. + virtual void onLazyReexportCalled(const CallThroughInfo &CTI) = 0; + }; + using OnTrampolinesReadyFn = unique_function> EntryAddrs)>; using EmitTrampolinesFn = @@ -189,7 +220,7 @@ class LazyReexportsManager : public ResourceManager { /// This will work both in-process and out-of-process. static Expected> Create(EmitTrampolinesFn EmitTrampolines, RedirectableSymbolManager &RSMgr, - JITDylib &PlatformJD); + JITDylib &PlatformJD, Listener *L = nullptr); LazyReexportsManager(LazyReexportsManager &&) = delete; LazyReexportsManager &operator=(LazyReexportsManager &&) = delete; @@ -199,12 +230,6 @@ class LazyReexportsManager : public ResourceManager { ResourceKey SrcK) override; private: - struct CallThroughInfo { - SymbolStringPtr Name; - SymbolStringPtr BodyName; - JITDylibSP JD; - }; - class MU; class Plugin; @@ -213,7 +238,7 @@ class LazyReexportsManager : public ResourceManager { LazyReexportsManager(EmitTrampolinesFn EmitTrampolines, RedirectableSymbolManager &RSMgr, JITDylib &PlatformJD, - Error &Err); + Listener *L, Error &Err); std::unique_ptr createLazyReexports(SymbolAliasMap Reexports); @@ -229,6 +254,7 @@ class LazyReexportsManager : public ResourceManager { ExecutionSession &ES; EmitTrampolinesFn EmitTrampolines; RedirectableSymbolManager &RSMgr; + Listener *L; DenseMap> KeyToReentryAddrs; DenseMap CallThroughs; @@ -242,6 +268,66 @@ lazyReexports(LazyReexportsManager &LRM, SymbolAliasMap Reexports) { return LRM.createLazyReexports(std::move(Reexports)); } +class SimpleLazyReexportsSpeculator : public LazyReexportsManager::Listener { + friend std::shared_ptr std::make_shared(); + +public: + using RecordExecutionFunction = + unique_function; + + static std::shared_ptr + Create(ExecutionSession &ES, RecordExecutionFunction RecordExec = {}) { + class make_shared_helper : public SimpleLazyReexportsSpeculator { + public: + make_shared_helper(ExecutionSession &ES, + RecordExecutionFunction RecordExec) + : SimpleLazyReexportsSpeculator(ES, std::move(RecordExec)) {} + }; + + auto Instance = + std::make_shared(ES, std::move(RecordExec)); + Instance->WeakThis = Instance; + return Instance; + } + + SimpleLazyReexportsSpeculator(SimpleLazyReexportsSpeculator &&) = delete; + SimpleLazyReexportsSpeculator & + operator=(SimpleLazyReexportsSpeculator &&) = delete; + ~SimpleLazyReexportsSpeculator() override; + + void onLazyReexportsCreated(JITDylib &JD, ResourceKey K, + const SymbolAliasMap &Reexports) override; + + void onLazyReexportsTransfered(JITDylib &JD, ResourceKey DstK, + ResourceKey SrcK) override; + + Error onLazyReexportsRemoved(JITDylib &JD, ResourceKey K) override; + + void onLazyReexportCalled(const CallThroughInfo &CTI) override; + + void addSpeculationSuggestions( + std::vector> NewSuggestions); + +private: + SimpleLazyReexportsSpeculator(ExecutionSession &ES, + RecordExecutionFunction RecordExec) + : ES(ES), RecordExec(std::move(RecordExec)) {} + + bool doNextSpeculativeLookup(); + + class SpeculateTask; + + using KeyToFunctionBodiesMap = + DenseMap>; + + ExecutionSession &ES; + RecordExecutionFunction RecordExec; + std::weak_ptr WeakThis; + DenseMap LazyReexports; + std::deque> SpeculateSuggestions; + bool SpeculateTaskActive = false; +}; + } // End namespace orc } // End namespace llvm diff --git a/llvm/include/llvm/ExecutionEngine/Orc/TaskDispatch.h b/llvm/include/llvm/ExecutionEngine/Orc/TaskDispatch.h index d7939864fd609..67164679f9e30 100644 --- a/llvm/include/llvm/ExecutionEngine/Orc/TaskDispatch.h +++ b/llvm/include/llvm/ExecutionEngine/Orc/TaskDispatch.h @@ -92,6 +92,16 @@ makeGenericNamedTask(FnT &&Fn, const char *Desc = nullptr) { Desc); } +/// IdleTask can be used as the basis for low-priority tasks, e.g. speculative +/// lookup. +class IdleTask : public RTTIExtends { +public: + static char ID; + +private: + void anchor() override; +}; + /// Abstract base for classes that dispatch ORC Tasks. class TaskDispatcher { public: @@ -118,9 +128,13 @@ class DynamicThreadPoolTaskDispatcher : public TaskDispatcher { DynamicThreadPoolTaskDispatcher( std::optional MaxMaterializationThreads) : MaxMaterializationThreads(MaxMaterializationThreads) {} + void dispatch(std::unique_ptr T) override; void shutdown() override; private: + bool canRunMaterializationTaskNow(); + bool canRunIdleTaskNow(); + std::mutex DispatchMutex; bool Shutdown = false; size_t Outstanding = 0; @@ -129,6 +143,7 @@ class DynamicThreadPoolTaskDispatcher : public TaskDispatcher { std::optional MaxMaterializationThreads; size_t NumMaterializationThreads = 0; std::deque> MaterializationTaskQueue; + std::deque> IdleTaskQueue; }; #endif // LLVM_ENABLE_THREADS diff --git a/llvm/lib/ExecutionEngine/Orc/JITLinkReentryTrampolines.cpp b/llvm/lib/ExecutionEngine/Orc/JITLinkReentryTrampolines.cpp index be574ef7279c2..d9f859654d41e 100644 --- a/llvm/lib/ExecutionEngine/Orc/JITLinkReentryTrampolines.cpp +++ b/llvm/lib/ExecutionEngine/Orc/JITLinkReentryTrampolines.cpp @@ -173,7 +173,8 @@ void JITLinkReentryTrampolines::emit(ResourceTrackerSP RT, Expected> createJITLinkLazyReexportsManager(ObjectLinkingLayer &ObjLinkingLayer, RedirectableSymbolManager &RSMgr, - JITDylib &PlatformJD) { + JITDylib &PlatformJD, + LazyReexportsManager::Listener *L) { auto JLT = JITLinkReentryTrampolines::Create(ObjLinkingLayer); if (!JLT) return JLT.takeError(); @@ -184,7 +185,7 @@ createJITLinkLazyReexportsManager(ObjectLinkingLayer &ObjLinkingLayer, OnTrampolinesReady) mutable { JLT->emit(std::move(RT), NumTrampolines, std::move(OnTrampolinesReady)); }, - RSMgr, PlatformJD); + RSMgr, PlatformJD, L); } } // namespace llvm::orc diff --git a/llvm/lib/ExecutionEngine/Orc/LazyReexports.cpp b/llvm/lib/ExecutionEngine/Orc/LazyReexports.cpp index df4539ba4329f..7b38621eba824 100644 --- a/llvm/lib/ExecutionEngine/Orc/LazyReexports.cpp +++ b/llvm/lib/ExecutionEngine/Orc/LazyReexports.cpp @@ -280,31 +280,34 @@ class LazyReexportsManager::Plugin : public ObjectLinkingLayer::Plugin { std::mutex M; }; +LazyReexportsManager::Listener::~Listener() = default; + Expected> LazyReexportsManager::Create(EmitTrampolinesFn EmitTrampolines, RedirectableSymbolManager &RSMgr, - JITDylib &PlatformJD) { + JITDylib &PlatformJD, Listener *L) { Error Err = Error::success(); std::unique_ptr LRM(new LazyReexportsManager( - std::move(EmitTrampolines), RSMgr, PlatformJD, Err)); + std::move(EmitTrampolines), RSMgr, PlatformJD, L, Err)); if (Err) return std::move(Err); return std::move(LRM); } Error LazyReexportsManager::handleRemoveResources(JITDylib &JD, ResourceKey K) { - JD.getExecutionSession().runSessionLocked([&]() { + return JD.getExecutionSession().runSessionLocked([&]() -> Error { auto I = KeyToReentryAddrs.find(K); - if (I != KeyToReentryAddrs.end()) { - auto &ReentryAddrs = I->second; - for (auto &ReentryAddr : ReentryAddrs) { - assert(CallThroughs.count(ReentryAddr) && "CallTrhough missing"); - CallThroughs.erase(ReentryAddr); - } - KeyToReentryAddrs.erase(I); + if (I == KeyToReentryAddrs.end()) + return Error::success(); + + auto &ReentryAddrs = I->second; + for (auto &ReentryAddr : ReentryAddrs) { + assert(CallThroughs.count(ReentryAddr) && "CallTrhough missing"); + CallThroughs.erase(ReentryAddr); } + KeyToReentryAddrs.erase(I); + return L ? L->onLazyReexportsRemoved(JD, K) : Error::success(); }); - return Error::success(); } void LazyReexportsManager::handleTransferResources(JITDylib &JD, @@ -323,14 +326,17 @@ void LazyReexportsManager::handleTransferResources(JITDylib &JD, DstAddrs.insert(DstAddrs.end(), SrcAddrs.begin(), SrcAddrs.end()); KeyToReentryAddrs.erase(I); } + if (L) + L->onLazyReexportsTransfered(JD, DstK, SrcK); } } LazyReexportsManager::LazyReexportsManager(EmitTrampolinesFn EmitTrampolines, RedirectableSymbolManager &RSMgr, - JITDylib &PlatformJD, Error &Err) + JITDylib &PlatformJD, Listener *L, + Error &Err) : ES(PlatformJD.getExecutionSession()), - EmitTrampolines(std::move(EmitTrampolines)), RSMgr(RSMgr) { + EmitTrampolines(std::move(EmitTrampolines)), RSMgr(RSMgr), L(L) { using namespace shared; @@ -384,17 +390,22 @@ void LazyReexportsManager::emitRedirectableSymbols( Redirs[Name] = (*ReentryPoints)[I++]; I = 0; - if (auto Err = MR->withResourceKeyDo([&](ResourceKey K) { - for (auto &[Name, AI] : Reexports) { - const auto &ReentryPoint = (*ReentryPoints)[I++]; - CallThroughs[ReentryPoint.getAddress()] = {Name, AI.Aliasee, - &MR->getTargetJITDylib()}; - KeyToReentryAddrs[K].push_back(ReentryPoint.getAddress()); - } - })) { - MR->getExecutionSession().reportError(std::move(Err)); - MR->failMaterialization(); - return; + if (!Reexports.empty()) { + if (auto Err = MR->withResourceKeyDo([&](ResourceKey K) { + auto &JD = MR->getTargetJITDylib(); + auto &ReentryAddrsForK = KeyToReentryAddrs[K]; + for (auto &[Name, AI] : Reexports) { + const auto &ReentryPoint = (*ReentryPoints)[I++]; + CallThroughs[ReentryPoint.getAddress()] = {&JD, Name, AI.Aliasee}; + ReentryAddrsForK.push_back(ReentryPoint.getAddress()); + } + if (L) + L->onLazyReexportsCreated(JD, K, Reexports); + })) { + MR->getExecutionSession().reportError(std::move(Err)); + MR->failMaterialization(); + return; + } } RSMgr.emitRedirectableSymbols(std::move(MR), std::move(Redirs)); @@ -415,6 +426,9 @@ void LazyReexportsManager::resolve(ResolveSendResultFn SendResult, LandingInfo = I->second; }); + if (L) + L->onLazyReexportCalled(LandingInfo); + SymbolInstance LandingSym(LandingInfo.JD, std::move(LandingInfo.BodyName)); LandingSym.lookupAsync([this, JD = std::move(LandingInfo.JD), ReentryName = std::move(LandingInfo.Name), @@ -432,5 +446,168 @@ void LazyReexportsManager::resolve(ResolveSendResultFn SendResult, }); } +class SimpleLazyReexportsSpeculator::SpeculateTask : public IdleTask { +public: + SpeculateTask(std::weak_ptr Speculator) + : Speculator(std::move(Speculator)) {} + + void printDescription(raw_ostream &OS) override { + OS << "Speculative Lookup Task"; + } + + void run() override { + if (auto S = Speculator.lock()) + S->doNextSpeculativeLookup(); + } + +private: + std::weak_ptr Speculator; +}; + +SimpleLazyReexportsSpeculator::~SimpleLazyReexportsSpeculator() { + for (auto &[JD, _] : LazyReexports) + JITDylibSP(JD)->Release(); +} + +void SimpleLazyReexportsSpeculator::onLazyReexportsCreated( + JITDylib &JD, ResourceKey K, const SymbolAliasMap &Reexports) { + if (!LazyReexports.count(&JD)) + JD.Retain(); + auto &BodiesVec = LazyReexports[&JD][K]; + for (auto &[Name, AI] : Reexports) + BodiesVec.push_back(AI.Aliasee); + if (!SpeculateTaskActive) { + SpeculateTaskActive = true; + ES.dispatchTask(std::make_unique(WeakThis)); + } +} + +void SimpleLazyReexportsSpeculator::onLazyReexportsTransfered( + JITDylib &JD, ResourceKey DstK, ResourceKey SrcK) { + + auto I = LazyReexports.find(&JD); + if (I == LazyReexports.end()) + return; + + auto &MapForJD = I->second; + auto J = MapForJD.find(SrcK); + if (J == MapForJD.end()) + return; + + // We have something to transfer. + auto K = MapForJD.find(DstK); + if (K == MapForJD.end()) { + auto Tmp = std::move(J->second); + MapForJD.erase(J); + MapForJD[DstK] = std::move(Tmp); + } else { + auto &SrcNames = J->second; + auto &DstNames = K->second; + DstNames.insert(DstNames.end(), SrcNames.begin(), SrcNames.end()); + MapForJD.erase(J); + } +} + +Error SimpleLazyReexportsSpeculator::onLazyReexportsRemoved(JITDylib &JD, + ResourceKey K) { + + auto I = LazyReexports.find(&JD); + if (I == LazyReexports.end()) + return Error::success(); + + auto &MapForJD = I->second; + MapForJD.erase(K); + + if (MapForJD.empty()) { + LazyReexports.erase(I); + JD.Release(); + } + + return Error::success(); +} + +void SimpleLazyReexportsSpeculator::onLazyReexportCalled( + const CallThroughInfo &CTI) { + if (RecordExec) + RecordExec(CTI); +} + +void SimpleLazyReexportsSpeculator::addSpeculationSuggestions( + std::vector> NewSuggestions) { + ES.runSessionLocked([&]() { + for (auto &[JDName, SymbolName] : NewSuggestions) + SpeculateSuggestions.push_back( + {std::move(JDName), std::move(SymbolName)}); + }); +} + +bool SimpleLazyReexportsSpeculator::doNextSpeculativeLookup() { + // Use existing speculation queue if available, otherwise take the next + // element from LazyReexports. + JITDylibSP SpeculateJD = nullptr; + SymbolStringPtr SpeculateFn; + + auto SpeculateAgain = ES.runSessionLocked([&]() { + while (!SpeculateSuggestions.empty()) { + auto [JDName, SymbolName] = std::move(SpeculateSuggestions.front()); + SpeculateSuggestions.pop_front(); + + if (auto *JD = ES.getJITDylibByName(JDName)) { + SpeculateJD = JD; + SpeculateFn = std::move(SymbolName); + break; + } + } + + if (!SpeculateJD) { + assert(!LazyReexports.empty() && "LazyReexports map is empty"); + auto LRItr = + std::next(LazyReexports.begin(), rand() % LazyReexports.size()); + auto &[JD, KeyToFnBodies] = *LRItr; + + assert(!KeyToFnBodies.empty() && "Key to function bodies map empty"); + auto KeyToFnBodiesItr = + std::next(KeyToFnBodies.begin(), rand() % KeyToFnBodies.size()); + auto &[Key, FnBodies] = *KeyToFnBodiesItr; + + assert(!FnBodies.empty() && "Function bodies list empty"); + auto FnBodyItr = std::next(FnBodies.begin(), rand() % FnBodies.size()); + + SpeculateJD = JITDylibSP(JD); + SpeculateFn = std::move(*FnBodyItr); + + FnBodies.erase(FnBodyItr); + if (FnBodies.empty()) { + KeyToFnBodies.erase(KeyToFnBodiesItr); + if (KeyToFnBodies.empty()) { + LRItr->first->Release(); + LazyReexports.erase(LRItr); + } + } + } + + SpeculateTaskActive = + !SpeculateSuggestions.empty() || !LazyReexports.empty(); + return SpeculateTaskActive; + }); + + LLVM_DEBUG({ + dbgs() << "Issuing speculative lookup for ( " << SpeculateJD->getName() + << ", " << SpeculateFn << " )...\n"; + }); + + ES.lookup( + LookupKind::Static, makeJITDylibSearchOrder(SpeculateJD.get()), + {{std::move(SpeculateFn), SymbolLookupFlags::WeaklyReferencedSymbol}}, + SymbolState::Ready, + [](Expected Result) { consumeError(Result.takeError()); }, + NoDependenciesToRegister); + + if (SpeculateAgain) + ES.dispatchTask(std::make_unique(WeakThis)); + + return false; +} + } // End namespace orc. } // End namespace llvm. diff --git a/llvm/lib/ExecutionEngine/Orc/TaskDispatch.cpp b/llvm/lib/ExecutionEngine/Orc/TaskDispatch.cpp index 1af17e85220db..e87a14f3ea7c4 100644 --- a/llvm/lib/ExecutionEngine/Orc/TaskDispatch.cpp +++ b/llvm/lib/ExecutionEngine/Orc/TaskDispatch.cpp @@ -15,9 +15,13 @@ namespace orc { char Task::ID = 0; char GenericNamedTask::ID = 0; +char IdleTask::ID = 0; + const char *GenericNamedTask::DefaultDescription = "Generic Task"; void Task::anchor() {} +void IdleTask::anchor() {} + TaskDispatcher::~TaskDispatcher() = default; void InPlaceTaskDispatcher::dispatch(std::unique_ptr T) { T->run(); } @@ -26,7 +30,15 @@ void InPlaceTaskDispatcher::shutdown() {} #if LLVM_ENABLE_THREADS void DynamicThreadPoolTaskDispatcher::dispatch(std::unique_ptr T) { - bool IsMaterializationTask = isa(*T); + + enum { Normal, Materialization, Idle } TaskKind; + + if (isa(*T)) + TaskKind = Materialization; + else if (isa(*T)) + TaskKind = Idle; + else + TaskKind = Normal; { std::lock_guard Lock(DispatchMutex); @@ -35,24 +47,24 @@ void DynamicThreadPoolTaskDispatcher::dispatch(std::unique_ptr T) { if (Shutdown) return; - if (IsMaterializationTask) { + if (TaskKind == Materialization) { // If this is a materialization task and there are too many running // already then queue this one up and return early. - if (MaxMaterializationThreads && - NumMaterializationThreads == *MaxMaterializationThreads) { - MaterializationTaskQueue.push_back(std::move(T)); - return; - } + if (!canRunMaterializationTaskNow()) + return MaterializationTaskQueue.push_back(std::move(T)); // Otherwise record that we have a materialization task running. ++NumMaterializationThreads; + } else if (TaskKind == Idle) { + if (!canRunIdleTaskNow()) + return IdleTaskQueue.push_back(std::move(T)); } ++Outstanding; } - std::thread([this, T = std::move(T), IsMaterializationTask]() mutable { + std::thread([this, T = std::move(T), TaskKind]() mutable { while (true) { // Run the task. @@ -67,18 +79,24 @@ void DynamicThreadPoolTaskDispatcher::dispatch(std::unique_ptr T) { // Check the work queue state and either proceed with the next task or // end this thread. std::lock_guard Lock(DispatchMutex); - if (!MaterializationTaskQueue.empty()) { + + if (TaskKind == Materialization) + --NumMaterializationThreads; + --Outstanding; + + if (!MaterializationTaskQueue.empty() && canRunMaterializationTaskNow()) { // If there are any materialization tasks running then steal that work. T = std::move(MaterializationTaskQueue.front()); MaterializationTaskQueue.pop_front(); - if (!IsMaterializationTask) { - ++NumMaterializationThreads; - IsMaterializationTask = true; - } + TaskKind = Materialization; + ++NumMaterializationThreads; + ++Outstanding; + } else if (!IdleTaskQueue.empty() && canRunIdleTaskNow()) { + T = std::move(IdleTaskQueue.front()); + IdleTaskQueue.pop_front(); + TaskKind = Idle; + ++Outstanding; } else { - if (IsMaterializationTask) - --NumMaterializationThreads; - --Outstanding; if (Outstanding == 0) OutstandingCV.notify_all(); return; @@ -92,6 +110,17 @@ void DynamicThreadPoolTaskDispatcher::shutdown() { Shutdown = true; OutstandingCV.wait(Lock, [this]() { return Outstanding == 0; }); } + +bool DynamicThreadPoolTaskDispatcher::canRunMaterializationTaskNow() { + return !MaxMaterializationThreads || + (NumMaterializationThreads < *MaxMaterializationThreads); +} + +bool DynamicThreadPoolTaskDispatcher::canRunIdleTaskNow() { + return !MaxMaterializationThreads || + (Outstanding < *MaxMaterializationThreads); +} + #endif } // namespace orc diff --git a/llvm/tools/llvm-jitlink/llvm-jitlink.cpp b/llvm/tools/llvm-jitlink/llvm-jitlink.cpp index 963c36322c8ab..ece8484fe8c7c 100644 --- a/llvm/tools/llvm-jitlink/llvm-jitlink.cpp +++ b/llvm/tools/llvm-jitlink/llvm-jitlink.cpp @@ -83,13 +83,35 @@ using namespace llvm::orc; static cl::OptionCategory JITLinkCategory("JITLink Options"); +static cl::list InputFiles(cl::Positional, cl::OneOrMore, + cl::desc("input files"), + cl::cat(JITLinkCategory)); + static cl::list LazyLink("lazy", cl::desc("Link the following file lazily"), cl::cat(JITLinkCategory)); -static cl::list InputFiles(cl::Positional, cl::OneOrMore, - cl::desc("input files"), - cl::cat(JITLinkCategory)); +enum class SpeculateKind { None, Simple }; + +cl::opt Speculate( + "speculate", cl::desc("Choose speculation scheme"), + cl::init(SpeculateKind::None), + cl::values(clEnumValN(SpeculateKind::None, "none", "No speculation"), + clEnumValN(SpeculateKind::Simple, "simple", + "Simple speculation")), + cl::cat(JITLinkCategory)); + +cl::opt SpeculateOrder( + "speculate-order", + cl::desc("A CSV file containing (JITDylib, Function) pairs to" + "speculatively look up"), + cl::cat(JITLinkCategory)); + +cl::opt RecordLazyExecs( + "record-lazy-execs", + cl::desc("Write lazy-function executions to a CSV file as (JITDylib, " + "function) pairs"), + cl::cat(JITLinkCategory)); static cl::opt MaterializationThreads( "num-threads", cl::desc("Number of materialization threads to use"), @@ -959,17 +981,50 @@ class PhonyExternalsGenerator : public DefinitionGenerator { }; Expected> -createLazyLinkingSupport(ObjectLinkingLayer &OLL, JITDylib &PlatformJD) { - auto RSMgr = JITLinkRedirectableSymbolManager::Create(OLL); +createLazyLinkingSupport(Session &S) { + auto RSMgr = JITLinkRedirectableSymbolManager::Create(S.ObjLayer); if (!RSMgr) return RSMgr.takeError(); - auto LRMgr = createJITLinkLazyReexportsManager(OLL, **RSMgr, PlatformJD); + std::shared_ptr Speculator; + switch (Speculate) { + case SpeculateKind::None: + break; + case SpeculateKind::Simple: + SimpleLazyReexportsSpeculator::RecordExecutionFunction RecordExecs; + + if (!RecordLazyExecs.empty()) + RecordExecs = [&S](const LazyReexportsManager::CallThroughInfo &CTI) { + S.LazyFnExecOrder.push_back({CTI.JD->getName(), CTI.BodyName}); + }; + + Speculator = + SimpleLazyReexportsSpeculator::Create(S.ES, std::move(RecordExecs)); + break; + } + + auto LRMgr = createJITLinkLazyReexportsManager( + S.ObjLayer, **RSMgr, *S.PlatformJD, Speculator.get()); if (!LRMgr) return LRMgr.takeError(); - return std::make_unique(std::move(*RSMgr), - std::move(*LRMgr), OLL); + return std::make_unique( + std::move(*RSMgr), std::move(Speculator), std::move(*LRMgr), S.ObjLayer); +} + +static Error writeLazyExecOrder(Session &S) { + if (RecordLazyExecs.empty()) + return Error::success(); + + std::error_code EC; + raw_fd_ostream ExecOrderOut(RecordLazyExecs, EC); + if (EC) + return createFileError(RecordLazyExecs, EC); + + for (auto &[JDName, FunctionName] : S.LazyFnExecOrder) + ExecOrderOut << JDName << ", " << FunctionName << "\n"; + + return Error::success(); } Expected> Session::Create(Triple TT, @@ -1017,8 +1072,7 @@ Expected> Session::Create(Triple TT, S->Features = std::move(Features); if (lazyLinkingRequested()) { - if (auto LazyLinking = - createLazyLinkingSupport(S->ObjLayer, *S->PlatformJD)) + if (auto LazyLinking = createLazyLinkingSupport(*S)) S->LazyLinking = std::move(*LazyLinking); else return LazyLinking.takeError(); @@ -1028,6 +1082,9 @@ Expected> Session::Create(Triple TT, } Session::~Session() { + if (auto Err = writeLazyExecOrder(*this)) + ES.reportError(std::move(Err)); + if (auto Err = ES.endSession()) ES.reportError(std::move(Err)); } @@ -1702,6 +1759,23 @@ static Error sanitizeArguments(const Triple &TT, const char *ArgV0) { return make_error( "Lazy linking cannot be used with -harness mode", inconvertibleErrorCode()); + } else if (Speculate != SpeculateKind::None) { + errs() << "Warning: -speculate ignored as there are no -lazy inputs\n"; + Speculate = SpeculateKind::None; + } + + if (Speculate == SpeculateKind::None) { + if (!SpeculateOrder.empty()) { + errs() << "Warning: -speculate-order ignored because speculation is " + "disabled\n"; + SpeculateOrder = ""; + } + + if (!RecordLazyExecs.empty()) { + errs() << "Warning: -record-lazy-execs ignored because speculation is " + "disabled\n"; + RecordLazyExecs = ""; + } } return Error::success(); @@ -2267,6 +2341,59 @@ static Error addLibraries(Session &S, return Error::success(); } +static Error addSpeculationOrder(Session &S) { + + if (SpeculateOrder.empty()) + return Error::success(); + + assert(S.LazyLinking && "SpeculateOrder set, but lazy linking not enabled"); + assert(S.LazyLinking->Speculator && "SpeculatoOrder set, but no speculator"); + + auto SpecOrderBuffer = getFile(SpeculateOrder); + if (!SpecOrderBuffer) + return SpecOrderBuffer.takeError(); + + StringRef LineStream((*SpecOrderBuffer)->getBuffer()); + std::vector> SpecOrder; + + size_t LineNumber = 0; + while (!LineStream.empty()) { + ++LineNumber; + + auto MakeSpecOrderErr = [&](StringRef Reason) { + return make_error("Error in speculation order file \"" + + SpeculateOrder + "\" on line " + + Twine(LineNumber) + ": " + Reason, + inconvertibleErrorCode()); + }; + + StringRef CurLine; + std::tie(CurLine, LineStream) = LineStream.split('\n'); + CurLine = CurLine.trim(); + if (CurLine.empty()) + continue; + + auto [JDName, FuncName] = CurLine.split(','); + + if (FuncName.empty()) + return MakeSpecOrderErr("missing ',' separator"); + + JDName = JDName.trim(); + if (JDName.empty()) + return MakeSpecOrderErr("no value for column 1 (JIT Dylib name)"); + + FuncName = FuncName.trim(); + if (FuncName.empty()) + return MakeSpecOrderErr("no value for column 2 (function name)"); + + SpecOrder.push_back({JDName.str(), S.ES.intern(FuncName)}); + } + + S.LazyLinking->Speculator->addSpeculationSuggestions(std::move(SpecOrder)); + + return Error::success(); +} + static Error addSessionInputs(Session &S) { std::map IdxToJD; DenseSet LazyLinkIdxs; @@ -2299,6 +2426,9 @@ static Error addSessionInputs(Session &S) { if (auto Err = addLibraries(S, IdxToJD, LazyLinkIdxs)) return Err; + if (auto Err = addSpeculationOrder(S)) + return Err; + return Error::success(); } diff --git a/llvm/tools/llvm-jitlink/llvm-jitlink.h b/llvm/tools/llvm-jitlink/llvm-jitlink.h index be3710971729a..92d667e797b88 100644 --- a/llvm/tools/llvm-jitlink/llvm-jitlink.h +++ b/llvm/tools/llvm-jitlink/llvm-jitlink.h @@ -33,13 +33,17 @@ namespace llvm { struct Session { struct LazyLinkingSupport { - LazyLinkingSupport(std::unique_ptr RSMgr, - std::unique_ptr LRMgr, - orc::ObjectLinkingLayer &ObjLinkingLayer) - : RSMgr(std::move(RSMgr)), LRMgr(std::move(LRMgr)), + LazyLinkingSupport( + std::unique_ptr RSMgr, + std::shared_ptr Speculator, + std::unique_ptr LRMgr, + orc::ObjectLinkingLayer &ObjLinkingLayer) + : RSMgr(std::move(RSMgr)), Speculator(std::move(Speculator)), + LRMgr(std::move(LRMgr)), LazyObjLinkingLayer(ObjLinkingLayer, *this->LRMgr) {} std::unique_ptr RSMgr; + std::shared_ptr Speculator; std::unique_ptr LRMgr; orc::LazyObjectLinkingLayer LazyObjLinkingLayer; }; @@ -52,6 +56,7 @@ struct Session { std::unique_ptr LazyLinking; orc::JITDylibSearchOrder JDSearchOrder; SubtargetFeatures Features; + std::vector> LazyFnExecOrder; ~Session();