| // Copyright 2010 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include "v8.h" |
| |
| #include "runtime-profiler.h" |
| |
| #include "assembler.h" |
| #include "code-stubs.h" |
| #include "compilation-cache.h" |
| #include "deoptimizer.h" |
| #include "execution.h" |
| #include "global-handles.h" |
| #include "scopeinfo.h" |
| #include "top.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| class PendingListNode : public Malloced { |
| public: |
| explicit PendingListNode(JSFunction* function); |
| ~PendingListNode() { Destroy(); } |
| |
| PendingListNode* next() const { return next_; } |
| void set_next(PendingListNode* node) { next_ = node; } |
| Handle<JSFunction> function() { return Handle<JSFunction>::cast(function_); } |
| |
| // If the function is garbage collected before we've had the chance |
| // to optimize it the weak handle will be null. |
| bool IsValid() { return !function_.is_null(); } |
| |
| // Returns the number of microseconds this node has been pending. |
| int Delay() const { return static_cast<int>(OS::Ticks() - start_); } |
| |
| private: |
| void Destroy(); |
| static void WeakCallback(v8::Persistent<v8::Value> object, void* data); |
| |
| PendingListNode* next_; |
| Handle<Object> function_; // Weak handle. |
| int64_t start_; |
| }; |
| |
| |
| enum SamplerState { |
| IN_NON_JS_STATE = 0, |
| IN_JS_STATE = 1 |
| }; |
| |
| |
| // Optimization sampler constants. |
| static const int kSamplerFrameCount = 2; |
| static const int kSamplerFrameWeight[kSamplerFrameCount] = { 2, 1 }; |
| static const int kSamplerWindowSize = 16; |
| |
| static const int kSamplerTicksBetweenThresholdAdjustment = 32; |
| |
| static const int kSamplerThresholdInit = 3; |
| static const int kSamplerThresholdMin = 1; |
| static const int kSamplerThresholdDelta = 1; |
| |
| static const int kSamplerThresholdSizeFactorInit = 3; |
| static const int kSamplerThresholdSizeFactorMin = 1; |
| static const int kSamplerThresholdSizeFactorDelta = 1; |
| |
| static const int kSizeLimit = 1500; |
| |
| static int sampler_threshold = kSamplerThresholdInit; |
| static int sampler_threshold_size_factor = kSamplerThresholdSizeFactorInit; |
| |
| static int sampler_ticks_until_threshold_adjustment = |
| kSamplerTicksBetweenThresholdAdjustment; |
| |
| // The ratio of ticks spent in JS code in percent. |
| static Atomic32 js_ratio; |
| |
| // The JSFunctions in the sampler window are not GC safe. Old-space |
| // pointers are not cleared during mark-sweep collection and therefore |
| // the window might contain stale pointers. The window is updated on |
| // scavenges and (parts of it) cleared on mark-sweep and |
| // mark-sweep-compact. |
| static Object* sampler_window[kSamplerWindowSize] = { NULL, }; |
| static int sampler_window_position = 0; |
| static int sampler_window_weight[kSamplerWindowSize] = { 0, }; |
| |
| |
| // Support for pending 'optimize soon' requests. |
| static PendingListNode* optimize_soon_list = NULL; |
| |
| |
| PendingListNode::PendingListNode(JSFunction* function) : next_(NULL) { |
| function_ = GlobalHandles::Create(function); |
| start_ = OS::Ticks(); |
| GlobalHandles::MakeWeak(function_.location(), this, &WeakCallback); |
| } |
| |
| |
| void PendingListNode::Destroy() { |
| if (!IsValid()) return; |
| GlobalHandles::Destroy(function_.location()); |
| function_= Handle<Object>::null(); |
| } |
| |
| |
| void PendingListNode::WeakCallback(v8::Persistent<v8::Value>, void* data) { |
| reinterpret_cast<PendingListNode*>(data)->Destroy(); |
| } |
| |
| |
| static bool IsOptimizable(JSFunction* function) { |
| if (Heap::InNewSpace(function)) return false; |
| Code* code = function->code(); |
| return code->kind() == Code::FUNCTION && code->optimizable(); |
| } |
| |
| |
| static void Optimize(JSFunction* function, bool eager, int delay) { |
| ASSERT(IsOptimizable(function)); |
| if (FLAG_trace_opt) { |
| PrintF("[marking (%s) ", eager ? "eagerly" : "lazily"); |
| function->PrintName(); |
| PrintF(" for recompilation"); |
| if (delay > 0) { |
| PrintF(" (delayed %0.3f ms)", static_cast<double>(delay) / 1000); |
| } |
| PrintF("]\n"); |
| } |
| |
| // The next call to the function will trigger optimization. |
| function->MarkForLazyRecompilation(); |
| } |
| |
| |
| static void AttemptOnStackReplacement(JSFunction* function) { |
| // See AlwaysFullCompiler (in compiler.cc) comment on why we need |
| // Debug::has_break_points(). |
| ASSERT(function->IsMarkedForLazyRecompilation()); |
| if (!FLAG_use_osr || Debug::has_break_points() || function->IsBuiltin()) { |
| return; |
| } |
| |
| SharedFunctionInfo* shared = function->shared(); |
| // If the code is not optimizable or references context slots, don't try OSR. |
| if (!shared->code()->optimizable() || !shared->allows_lazy_compilation()) { |
| return; |
| } |
| |
| // We are not prepared to do OSR for a function that already has an |
| // allocated arguments object. The optimized code would bypass it for |
| // arguments accesses, which is unsound. Don't try OSR. |
| if (shared->scope_info()->HasArgumentsShadow()) return; |
| |
| // We're using on-stack replacement: patch the unoptimized code so that |
| // any back edge in any unoptimized frame will trigger on-stack |
| // replacement for that frame. |
| if (FLAG_trace_osr) { |
| PrintF("[patching stack checks in "); |
| function->PrintName(); |
| PrintF(" for on-stack replacement]\n"); |
| } |
| |
| // Get the stack check stub code object to match against. We aren't |
| // prepared to generate it, but we don't expect to have to. |
| StackCheckStub check_stub; |
| Object* check_code; |
| MaybeObject* maybe_check_code = check_stub.TryGetCode(); |
| if (maybe_check_code->ToObject(&check_code)) { |
| Code* replacement_code = Builtins::builtin(Builtins::OnStackReplacement); |
| Code* unoptimized_code = shared->code(); |
| Deoptimizer::PatchStackCheckCode(unoptimized_code, |
| Code::cast(check_code), |
| replacement_code); |
| } |
| } |
| |
| |
| static void ClearSampleBuffer() { |
| for (int i = 0; i < kSamplerWindowSize; i++) { |
| sampler_window[i] = NULL; |
| sampler_window_weight[i] = 0; |
| } |
| } |
| |
| |
| static void ClearSampleBufferNewSpaceEntries() { |
| for (int i = 0; i < kSamplerWindowSize; i++) { |
| if (Heap::InNewSpace(sampler_window[i])) { |
| sampler_window[i] = NULL; |
| sampler_window_weight[i] = 0; |
| } |
| } |
| } |
| |
| |
| static int LookupSample(JSFunction* function) { |
| int weight = 0; |
| for (int i = 0; i < kSamplerWindowSize; i++) { |
| Object* sample = sampler_window[i]; |
| if (sample != NULL) { |
| if (function == sample) { |
| weight += sampler_window_weight[i]; |
| } |
| } |
| } |
| return weight; |
| } |
| |
| |
| static void AddSample(JSFunction* function, int weight) { |
| ASSERT(IsPowerOf2(kSamplerWindowSize)); |
| sampler_window[sampler_window_position] = function; |
| sampler_window_weight[sampler_window_position] = weight; |
| sampler_window_position = (sampler_window_position + 1) & |
| (kSamplerWindowSize - 1); |
| } |
| |
| |
| void RuntimeProfiler::OptimizeNow() { |
| HandleScope scope; |
| PendingListNode* current = optimize_soon_list; |
| while (current != NULL) { |
| PendingListNode* next = current->next(); |
| if (current->IsValid()) { |
| Handle<JSFunction> function = current->function(); |
| int delay = current->Delay(); |
| if (IsOptimizable(*function)) { |
| Optimize(*function, true, delay); |
| } |
| } |
| delete current; |
| current = next; |
| } |
| optimize_soon_list = NULL; |
| |
| // Run through the JavaScript frames and collect them. If we already |
| // have a sample of the function, we mark it for optimizations |
| // (eagerly or lazily). |
| JSFunction* samples[kSamplerFrameCount]; |
| int sample_count = 0; |
| int frame_count = 0; |
| for (JavaScriptFrameIterator it; |
| frame_count++ < kSamplerFrameCount && !it.done(); |
| it.Advance()) { |
| JavaScriptFrame* frame = it.frame(); |
| JSFunction* function = JSFunction::cast(frame->function()); |
| |
| // Adjust threshold each time we have processed |
| // a certain number of ticks. |
| if (sampler_ticks_until_threshold_adjustment > 0) { |
| sampler_ticks_until_threshold_adjustment--; |
| if (sampler_ticks_until_threshold_adjustment <= 0) { |
| // If the threshold is not already at the minimum |
| // modify and reset the ticks until next adjustment. |
| if (sampler_threshold > kSamplerThresholdMin) { |
| sampler_threshold -= kSamplerThresholdDelta; |
| sampler_ticks_until_threshold_adjustment = |
| kSamplerTicksBetweenThresholdAdjustment; |
| } |
| } |
| } |
| |
| if (function->IsMarkedForLazyRecompilation()) { |
| Code* unoptimized = function->shared()->code(); |
| int nesting = unoptimized->allow_osr_at_loop_nesting_level(); |
| if (nesting == 0) AttemptOnStackReplacement(function); |
| int new_nesting = Min(nesting + 1, Code::kMaxLoopNestingMarker); |
| unoptimized->set_allow_osr_at_loop_nesting_level(new_nesting); |
| } |
| |
| // Do not record non-optimizable functions. |
| if (!IsOptimizable(function)) continue; |
| samples[sample_count++] = function; |
| |
| int function_size = function->shared()->SourceSize(); |
| int threshold_size_factor = (function_size > kSizeLimit) |
| ? sampler_threshold_size_factor |
| : 1; |
| |
| int threshold = sampler_threshold * threshold_size_factor; |
| int current_js_ratio = NoBarrier_Load(&js_ratio); |
| |
| // Adjust threshold depending on the ratio of time spent |
| // in JS code. |
| if (current_js_ratio < 20) { |
| // If we spend less than 20% of the time in JS code, |
| // do not optimize. |
| continue; |
| } else if (current_js_ratio < 75) { |
| // Below 75% of time spent in JS code, only optimize very |
| // frequently used functions. |
| threshold *= 3; |
| } |
| |
| if (LookupSample(function) >= threshold) { |
| Optimize(function, false, 0); |
| CompilationCache::MarkForEagerOptimizing(Handle<JSFunction>(function)); |
| } |
| } |
| |
| // Add the collected functions as samples. It's important not to do |
| // this as part of collecting them because this will interfere with |
| // the sample lookup in case of recursive functions. |
| for (int i = 0; i < sample_count; i++) { |
| AddSample(samples[i], kSamplerFrameWeight[i]); |
| } |
| } |
| |
| |
| void RuntimeProfiler::OptimizeSoon(JSFunction* function) { |
| if (!IsOptimizable(function)) return; |
| PendingListNode* node = new PendingListNode(function); |
| node->set_next(optimize_soon_list); |
| optimize_soon_list = node; |
| } |
| |
| |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| static void UpdateStateRatio(SamplerState current_state) { |
| static const int kStateWindowSize = 128; |
| static SamplerState state_window[kStateWindowSize]; |
| static int state_window_position = 0; |
| static int state_counts[2] = { kStateWindowSize, 0 }; |
| |
| SamplerState old_state = state_window[state_window_position]; |
| state_counts[old_state]--; |
| state_window[state_window_position] = current_state; |
| state_counts[current_state]++; |
| ASSERT(IsPowerOf2(kStateWindowSize)); |
| state_window_position = (state_window_position + 1) & |
| (kStateWindowSize - 1); |
| NoBarrier_Store(&js_ratio, state_counts[IN_JS_STATE] * 100 / |
| kStateWindowSize); |
| } |
| #endif |
| |
| |
| void RuntimeProfiler::NotifyTick() { |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| // Record state sample. |
| SamplerState state = Top::IsInJSState() |
| ? IN_JS_STATE |
| : IN_NON_JS_STATE; |
| UpdateStateRatio(state); |
| StackGuard::RequestRuntimeProfilerTick(); |
| #endif |
| } |
| |
| |
| void RuntimeProfiler::MarkCompactPrologue(bool is_compacting) { |
| if (is_compacting) { |
| // Clear all samples before mark-sweep-compact because every |
| // function might move. |
| ClearSampleBuffer(); |
| } else { |
| // Clear only new space entries on mark-sweep since none of the |
| // old-space functions will move. |
| ClearSampleBufferNewSpaceEntries(); |
| } |
| } |
| |
| |
| bool IsEqual(void* first, void* second) { |
| return first == second; |
| } |
| |
| |
| void RuntimeProfiler::Setup() { |
| ClearSampleBuffer(); |
| // If the ticker hasn't already started, make sure to do so to get |
| // the ticks for the runtime profiler. |
| if (IsEnabled()) Logger::EnsureTickerStarted(); |
| } |
| |
| |
| void RuntimeProfiler::Reset() { |
| sampler_threshold = kSamplerThresholdInit; |
| sampler_ticks_until_threshold_adjustment = |
| kSamplerTicksBetweenThresholdAdjustment; |
| sampler_threshold_size_factor = kSamplerThresholdSizeFactorInit; |
| } |
| |
| |
| void RuntimeProfiler::TearDown() { |
| // Nothing to do. |
| } |
| |
| |
| Object** RuntimeProfiler::SamplerWindowAddress() { |
| return sampler_window; |
| } |
| |
| |
| int RuntimeProfiler::SamplerWindowSize() { |
| return kSamplerWindowSize; |
| } |
| |
| |
| bool RuntimeProfilerRateLimiter::SuspendIfNecessary() { |
| #ifdef ENABLE_LOGGING_AND_PROFILING |
| static const int kNonJSTicksThreshold = 100; |
| // We suspend the runtime profiler thread when not running |
| // JavaScript. If the CPU profiler is active we must not do this |
| // because it samples both JavaScript and C++ code. |
| if (RuntimeProfiler::IsEnabled() && |
| !CpuProfiler::is_profiling() && |
| !(FLAG_prof && FLAG_prof_auto)) { |
| if (Top::IsInJSState()) { |
| non_js_ticks_ = 0; |
| } else { |
| if (non_js_ticks_ < kNonJSTicksThreshold) { |
| ++non_js_ticks_; |
| } else { |
| if (Top::WaitForJSState()) return true; |
| } |
| } |
| } |
| #endif |
| return false; |
| } |
| |
| |
| } } // namespace v8::internal |