| // Copyright 2012 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 "bootstrapper.h" |
| #include "code-stubs.h" |
| #include "compilation-cache.h" |
| #include "execution.h" |
| #include "full-codegen.h" |
| #include "global-handles.h" |
| #include "isolate-inl.h" |
| #include "mark-compact.h" |
| #include "platform.h" |
| #include "scopeinfo.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| // Optimization sampler constants. |
| static const int kSamplerFrameCount = 2; |
| |
| // Constants for statistical profiler. |
| static const int kSamplerFrameWeight[kSamplerFrameCount] = { 2, 1 }; |
| |
| 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 kSizeLimit = 1500; |
| |
| // Constants for counter based profiler. |
| |
| // Number of times a function has to be seen on the stack before it is |
| // optimized. |
| static const int kProfilerTicksBeforeOptimization = 2; |
| // If the function optimization was disabled due to high deoptimization count, |
| // but the function is hot and has been seen on the stack this number of times, |
| // then we try to reenable optimization for this function. |
| static const int kProfilerTicksBeforeReenablingOptimization = 250; |
| // If a function does not have enough type info (according to |
| // FLAG_type_info_threshold), but has seen a huge number of ticks, |
| // optimize it as it is. |
| static const int kTicksWhenNotEnoughTypeInfo = 100; |
| // We only have one byte to store the number of ticks. |
| STATIC_ASSERT(kProfilerTicksBeforeOptimization < 256); |
| STATIC_ASSERT(kProfilerTicksBeforeReenablingOptimization < 256); |
| STATIC_ASSERT(kTicksWhenNotEnoughTypeInfo < 256); |
| |
| // Maximum size in bytes of generate code for a function to allow OSR. |
| static const int kOSRCodeSizeAllowanceBase = |
| 100 * FullCodeGenerator::kCodeSizeMultiplier; |
| |
| static const int kOSRCodeSizeAllowancePerTick = |
| 3 * FullCodeGenerator::kCodeSizeMultiplier; |
| |
| // Maximum size in bytes of generated code for a function to be optimized |
| // the very first time it is seen on the stack. |
| static const int kMaxSizeEarlyOpt = |
| 5 * FullCodeGenerator::kCodeSizeMultiplier; |
| |
| |
| RuntimeProfiler::RuntimeProfiler(Isolate* isolate) |
| : isolate_(isolate), |
| sampler_threshold_(kSamplerThresholdInit), |
| sampler_threshold_size_factor_(kSamplerThresholdSizeFactorInit), |
| sampler_ticks_until_threshold_adjustment_( |
| kSamplerTicksBetweenThresholdAdjustment), |
| sampler_window_position_(0), |
| any_ic_changed_(false), |
| code_generated_(false) { |
| ClearSampleBuffer(); |
| } |
| |
| |
| static void GetICCounts(Code* shared_code, |
| int* ic_with_type_info_count, |
| int* ic_total_count, |
| int* percentage) { |
| *ic_total_count = 0; |
| *ic_with_type_info_count = 0; |
| Object* raw_info = shared_code->type_feedback_info(); |
| if (raw_info->IsTypeFeedbackInfo()) { |
| TypeFeedbackInfo* info = TypeFeedbackInfo::cast(raw_info); |
| *ic_with_type_info_count = info->ic_with_type_info_count(); |
| *ic_total_count = info->ic_total_count(); |
| } |
| *percentage = *ic_total_count > 0 |
| ? 100 * *ic_with_type_info_count / *ic_total_count |
| : 100; |
| } |
| |
| |
| void RuntimeProfiler::Optimize(JSFunction* function, const char* reason) { |
| ASSERT(function->IsOptimizable()); |
| |
| if (FLAG_trace_opt && function->PassesFilter(FLAG_hydrogen_filter)) { |
| PrintF("[marking "); |
| function->ShortPrint(); |
| PrintF(" for recompilation, reason: %s", reason); |
| if (FLAG_type_info_threshold > 0) { |
| int typeinfo, total, percentage; |
| GetICCounts(function->shared()->code(), &typeinfo, &total, &percentage); |
| PrintF(", ICs with typeinfo: %d/%d (%d%%)", typeinfo, total, percentage); |
| } |
| PrintF("]\n"); |
| } |
| |
| |
| if (FLAG_concurrent_recompilation && !isolate_->bootstrapper()->IsActive()) { |
| if (FLAG_concurrent_osr && |
| isolate_->optimizing_compiler_thread()->IsQueuedForOSR(function)) { |
| // Do not attempt regular recompilation if we already queued this for OSR. |
| // TODO(yangguo): This is necessary so that we don't install optimized |
| // code on a function that is already optimized, since OSR and regular |
| // recompilation race. This goes away as soon as OSR becomes one-shot. |
| return; |
| } |
| ASSERT(!function->IsInRecompileQueue()); |
| function->MarkForConcurrentRecompilation(); |
| } else { |
| // The next call to the function will trigger optimization. |
| function->MarkForLazyRecompilation(); |
| } |
| } |
| |
| |
| void RuntimeProfiler::AttemptOnStackReplacement(JSFunction* function) { |
| // See AlwaysFullCompiler (in compiler.cc) comment on why we need |
| // Debug::has_break_points(). |
| if (!FLAG_use_osr || |
| isolate_->DebuggerHasBreakPoints() || |
| function->IsBuiltin()) { |
| return; |
| } |
| |
| SharedFunctionInfo* shared = function->shared(); |
| // If the code is not optimizable, don't try OSR. |
| if (!shared->code()->optimizable()) 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->uses_arguments()) 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("[OSR - patching back edges in "); |
| function->PrintName(); |
| PrintF("]\n"); |
| } |
| |
| BackEdgeTable::Patch(isolate_, shared->code()); |
| } |
| |
| |
| void RuntimeProfiler::ClearSampleBuffer() { |
| memset(sampler_window_, 0, sizeof(sampler_window_)); |
| memset(sampler_window_weight_, 0, sizeof(sampler_window_weight_)); |
| } |
| |
| |
| int RuntimeProfiler::LookupSample(JSFunction* function) { |
| int weight = 0; |
| for (int i = 0; i < kSamplerWindowSize; i++) { |
| Object* sample = sampler_window_[i]; |
| if (sample != NULL) { |
| bool fits = FLAG_lookup_sample_by_shared |
| ? (function->shared() == JSFunction::cast(sample)->shared()) |
| : (function == JSFunction::cast(sample)); |
| if (fits) { |
| weight += sampler_window_weight_[i]; |
| } |
| } |
| } |
| return weight; |
| } |
| |
| |
| void RuntimeProfiler::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(isolate_); |
| |
| if (isolate_->DebuggerHasBreakPoints()) return; |
| |
| DisallowHeapAllocation no_gc; |
| |
| // 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; |
| int frame_count_limit = FLAG_watch_ic_patching ? FLAG_frame_count |
| : kSamplerFrameCount; |
| for (JavaScriptFrameIterator it(isolate_); |
| frame_count++ < frame_count_limit && !it.done(); |
| it.Advance()) { |
| JavaScriptFrame* frame = it.frame(); |
| JSFunction* function = frame->function(); |
| |
| if (!FLAG_watch_ic_patching) { |
| // 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; |
| } |
| } |
| } |
| } |
| |
| SharedFunctionInfo* shared = function->shared(); |
| Code* shared_code = shared->code(); |
| |
| if (shared_code->kind() != Code::FUNCTION) continue; |
| if (function->IsInRecompileQueue()) continue; |
| |
| if (FLAG_always_osr && |
| shared_code->allow_osr_at_loop_nesting_level() == 0) { |
| // Testing mode: always try an OSR compile for every function. |
| for (int i = 0; i < Code::kMaxLoopNestingMarker; i++) { |
| // TODO(titzer): fix AttemptOnStackReplacement to avoid this dumb loop. |
| shared_code->set_allow_osr_at_loop_nesting_level(i); |
| AttemptOnStackReplacement(function); |
| } |
| // Fall through and do a normal optimized compile as well. |
| } else if (!frame->is_optimized() && |
| (function->IsMarkedForLazyRecompilation() || |
| function->IsMarkedForConcurrentRecompilation() || |
| function->IsOptimized())) { |
| // Attempt OSR if we are still running unoptimized code even though the |
| // the function has long been marked or even already been optimized. |
| int ticks = shared_code->profiler_ticks(); |
| int allowance = kOSRCodeSizeAllowanceBase + |
| ticks * kOSRCodeSizeAllowancePerTick; |
| if (shared_code->CodeSize() > allowance) { |
| if (ticks < 255) shared_code->set_profiler_ticks(ticks + 1); |
| } else { |
| int nesting = shared_code->allow_osr_at_loop_nesting_level(); |
| if (nesting < Code::kMaxLoopNestingMarker) { |
| int new_nesting = nesting + 1; |
| shared_code->set_allow_osr_at_loop_nesting_level(new_nesting); |
| AttemptOnStackReplacement(function); |
| } |
| } |
| continue; |
| } |
| |
| // Only record top-level code on top of the execution stack and |
| // avoid optimizing excessively large scripts since top-level code |
| // will be executed only once. |
| const int kMaxToplevelSourceSize = 10 * 1024; |
| if (shared->is_toplevel() && |
| (frame_count > 1 || shared->SourceSize() > kMaxToplevelSourceSize)) { |
| continue; |
| } |
| |
| // Do not record non-optimizable functions. |
| if (shared->optimization_disabled()) { |
| if (shared->deopt_count() >= FLAG_max_opt_count) { |
| // If optimization was disabled due to many deoptimizations, |
| // then check if the function is hot and try to reenable optimization. |
| int ticks = shared_code->profiler_ticks(); |
| if (ticks >= kProfilerTicksBeforeReenablingOptimization) { |
| shared_code->set_profiler_ticks(0); |
| shared->TryReenableOptimization(); |
| } else { |
| shared_code->set_profiler_ticks(ticks + 1); |
| } |
| } |
| continue; |
| } |
| if (!function->IsOptimizable()) continue; |
| |
| if (FLAG_watch_ic_patching) { |
| int ticks = shared_code->profiler_ticks(); |
| |
| if (ticks >= kProfilerTicksBeforeOptimization) { |
| int typeinfo, total, percentage; |
| GetICCounts(shared_code, &typeinfo, &total, &percentage); |
| if (percentage >= FLAG_type_info_threshold) { |
| // If this particular function hasn't had any ICs patched for enough |
| // ticks, optimize it now. |
| Optimize(function, "hot and stable"); |
| } else if (ticks >= kTicksWhenNotEnoughTypeInfo) { |
| Optimize(function, "not much type info but very hot"); |
| } else { |
| shared_code->set_profiler_ticks(ticks + 1); |
| if (FLAG_trace_opt_verbose) { |
| PrintF("[not yet optimizing "); |
| function->PrintName(); |
| PrintF(", not enough type info: %d/%d (%d%%)]\n", |
| typeinfo, total, percentage); |
| } |
| } |
| } else if (!any_ic_changed_ && |
| shared_code->instruction_size() < kMaxSizeEarlyOpt) { |
| // If no IC was patched since the last tick and this function is very |
| // small, optimistically optimize it now. |
| Optimize(function, "small function"); |
| } else { |
| shared_code->set_profiler_ticks(ticks + 1); |
| } |
| } else { // !FLAG_watch_ic_patching |
| 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; |
| |
| if (LookupSample(function) >= threshold) { |
| Optimize(function, "sampler window lookup"); |
| } |
| } |
| } |
| if (FLAG_watch_ic_patching) { |
| any_ic_changed_ = false; |
| } else { // !FLAG_watch_ic_patching |
| // 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::SetUp() { |
| if (!FLAG_watch_ic_patching) { |
| ClearSampleBuffer(); |
| } |
| } |
| |
| |
| void RuntimeProfiler::Reset() { |
| if (!FLAG_watch_ic_patching) { |
| sampler_threshold_ = kSamplerThresholdInit; |
| sampler_threshold_size_factor_ = kSamplerThresholdSizeFactorInit; |
| sampler_ticks_until_threshold_adjustment_ = |
| kSamplerTicksBetweenThresholdAdjustment; |
| } |
| } |
| |
| |
| void RuntimeProfiler::TearDown() { |
| // Nothing to do. |
| } |
| |
| |
| // Update the pointers in the sampler window after a GC. |
| void RuntimeProfiler::UpdateSamplesAfterScavenge() { |
| for (int i = 0; i < kSamplerWindowSize; i++) { |
| Object* function = sampler_window_[i]; |
| if (function != NULL && isolate_->heap()->InNewSpace(function)) { |
| MapWord map_word = HeapObject::cast(function)->map_word(); |
| if (map_word.IsForwardingAddress()) { |
| sampler_window_[i] = map_word.ToForwardingAddress(); |
| } else { |
| sampler_window_[i] = NULL; |
| } |
| } |
| } |
| } |
| |
| |
| void RuntimeProfiler::RemoveDeadSamples() { |
| for (int i = 0; i < kSamplerWindowSize; i++) { |
| Object* function = sampler_window_[i]; |
| if (function != NULL && |
| !Marking::MarkBitFrom(HeapObject::cast(function)).Get()) { |
| sampler_window_[i] = NULL; |
| } |
| } |
| } |
| |
| |
| void RuntimeProfiler::UpdateSamplesAfterCompact(ObjectVisitor* visitor) { |
| for (int i = 0; i < kSamplerWindowSize; i++) { |
| visitor->VisitPointer(&sampler_window_[i]); |
| } |
| } |
| |
| |
| } } // namespace v8::internal |