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Implement missing functionality for job based recompilation

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BUG=v8:3608
R=bmeurer@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/816363003

Cr-Commit-Position: refs/heads/master@{#25925}
This commit is contained in:
jochen 2014-12-22 05:52:56 -08:00 committed by Commit bot
parent 1ec1f5957f
commit 88feffc2ab
3 changed files with 133 additions and 82 deletions
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1
src/flag-definitions.h
View File

@ -356,7 +356,6 @@ DEFINE_BOOL(job_based_recompilation, false,
"post tasks to v8::Platform instead of using a thread for "
"concurrent recompilation")
DEFINE_IMPLICATION(job_based_recompilation, concurrent_recompilation)
DEFINE_NEG_IMPLICATION(job_based_recompilation, block_concurrent_recompilation)
DEFINE_BOOL(trace_concurrent_recompilation, false,
"track concurrent recompilation")
DEFINE_INT(concurrent_recompilation_queue_length, 8,

195
src/optimizing-compiler-thread.cc
View File

@ -15,10 +15,34 @@
namespace v8 {
namespace internal {
namespace {
void DisposeOptimizedCompileJob(OptimizedCompileJob* job,
bool restore_function_code) {
// The recompile job is allocated in the CompilationInfo's zone.
CompilationInfo* info = job->info();
if (restore_function_code) {
if (info->is_osr()) {
if (!job->IsWaitingForInstall()) {
// Remove stack check that guards OSR entry on original code.
Handle<Code> code = info->unoptimized_code();
uint32_t offset = code->TranslateAstIdToPcOffset(info->osr_ast_id());
BackEdgeTable::RemoveStackCheck(code, offset);
}
} else {
Handle<JSFunction> function = info->closure();
function->ReplaceCode(function->shared()->code());
}
}
delete info;
}
} // namespace
class OptimizingCompilerThread::CompileTask : public v8::Task {
public:
CompileTask(Isolate* isolate, OptimizedCompileJob* job)
: isolate_(isolate), job_(job) {}
explicit CompileTask(Isolate* isolate) : isolate_(isolate) {}
virtual ~CompileTask() {}
@ -29,30 +53,41 @@ class OptimizingCompilerThread::CompileTask : public v8::Task {
DisallowHandleAllocation no_handles;
DisallowHandleDereference no_deref;
// The function may have already been optimized by OSR. Simply continue.
OptimizedCompileJob::Status status = job_->OptimizeGraph();
USE(status); // Prevent an unused-variable error in release mode.
DCHECK(status != OptimizedCompileJob::FAILED);
TimerEventScope<TimerEventRecompileConcurrent> timer(isolate_);
// The function may have already been optimized by OSR. Simply continue.
// Use a mutex to make sure that functions marked for install
// are always also queued.
{
base::LockGuard<base::Mutex> lock_guard(
&isolate_->optimizing_compiler_thread()->output_queue_mutex_);
isolate_->optimizing_compiler_thread()->output_queue_.Enqueue(job_);
OptimizingCompilerThread* thread = isolate_->optimizing_compiler_thread();
if (thread->recompilation_delay_ != 0) {
base::OS::Sleep(thread->recompilation_delay_);
}
isolate_->stack_guard()->RequestInstallCode();
{
base::LockGuard<base::Mutex> lock_guard(
&isolate_->optimizing_compiler_thread()->input_queue_mutex_);
isolate_->optimizing_compiler_thread()->input_queue_length_--;
StopFlag flag;
OptimizedCompileJob* job = thread->NextInput(&flag);
if (flag == CONTINUE) {
thread->CompileNext(job);
} else {
AllowHandleDereference allow_handle_dereference;
if (!job->info()->is_osr()) {
DisposeOptimizedCompileJob(job, true);
}
}
isolate_->optimizing_compiler_thread()->input_queue_semaphore_.Signal();
bool signal = false;
{
base::LockGuard<base::RecursiveMutex> lock(&thread->task_count_mutex_);
if (--thread->task_count_ == 0) {
if (static_cast<StopFlag>(base::Acquire_Load(&thread->stop_thread_)) ==
FLUSH) {
base::Release_Store(&thread->stop_thread_,
static_cast<base::AtomicWord>(CONTINUE));
signal = true;
}
}
}
if (signal) thread->stop_semaphore_.Signal();
}
Isolate* isolate_;
OptimizedCompileJob* job_;
DISALLOW_COPY_AND_ASSIGN(CompileTask);
};
@ -93,8 +128,8 @@ void OptimizingCompilerThread::Run() {
input_queue_semaphore_.Wait();
TimerEventScope<TimerEventRecompileConcurrent> timer(isolate_);
if (FLAG_concurrent_recompilation_delay != 0) {
base::OS::Sleep(FLAG_concurrent_recompilation_delay);
if (recompilation_delay_ != 0) {
base::OS::Sleep(recompilation_delay_);
}
switch (static_cast<StopFlag>(base::Acquire_Load(&stop_thread_))) {
@ -121,7 +156,7 @@ void OptimizingCompilerThread::Run() {
base::ElapsedTimer compiling_timer;
if (tracing_enabled_) compiling_timer.Start();
CompileNext();
CompileNext(NextInput());
if (tracing_enabled_) {
time_spent_compiling_ += compiling_timer.Elapsed();
@ -130,20 +165,27 @@ void OptimizingCompilerThread::Run() {
}
OptimizedCompileJob* OptimizingCompilerThread::NextInput() {
OptimizedCompileJob* OptimizingCompilerThread::NextInput(StopFlag* flag) {
base::LockGuard<base::Mutex> access_input_queue_(&input_queue_mutex_);
DCHECK(!job_based_recompilation_);
if (input_queue_length_ == 0) return NULL;
if (input_queue_length_ == 0) {
if (flag) {
UNREACHABLE();
*flag = CONTINUE;
}
return NULL;
}
OptimizedCompileJob* job = input_queue_[InputQueueIndex(0)];
DCHECK_NE(NULL, job);
input_queue_shift_ = InputQueueIndex(1);
input_queue_length_--;
if (flag) {
*flag = static_cast<StopFlag>(base::Acquire_Load(&stop_thread_));
}
return job;
}
void OptimizingCompilerThread::CompileNext() {
OptimizedCompileJob* job = NextInput();
void OptimizingCompilerThread::CompileNext(OptimizedCompileJob* job) {
DCHECK_NE(NULL, job);
// The function may have already been optimized by OSR. Simply continue.
@ -154,36 +196,17 @@ void OptimizingCompilerThread::CompileNext() {
// The function may have already been optimized by OSR. Simply continue.
// Use a mutex to make sure that functions marked for install
// are always also queued.
if (job_based_recompilation_) output_queue_mutex_.Lock();
output_queue_.Enqueue(job);
if (job_based_recompilation_) output_queue_mutex_.Unlock();
isolate_->stack_guard()->RequestInstallCode();
}
static void DisposeOptimizedCompileJob(OptimizedCompileJob* job,
bool restore_function_code) {
// The recompile job is allocated in the CompilationInfo's zone.
CompilationInfo* info = job->info();
if (restore_function_code) {
if (info->is_osr()) {
if (!job->IsWaitingForInstall()) {
// Remove stack check that guards OSR entry on original code.
Handle<Code> code = info->unoptimized_code();
uint32_t offset = code->TranslateAstIdToPcOffset(info->osr_ast_id());
BackEdgeTable::RemoveStackCheck(code, offset);
}
} else {
Handle<JSFunction> function = info->closure();
function->ReplaceCode(function->shared()->code());
}
}
delete info;
}
void OptimizingCompilerThread::FlushInputQueue(bool restore_function_code) {
DCHECK(!job_based_recompilation_);
OptimizedCompileJob* job;
while ((job = NextInput())) {
DCHECK(!job_based_recompilation_);
// This should not block, since we have one signal on the input queue
// semaphore corresponding to each element in the input queue.
input_queue_semaphore_.Wait();
@ -196,6 +219,7 @@ void OptimizingCompilerThread::FlushInputQueue(bool restore_function_code) {
void OptimizingCompilerThread::FlushOutputQueue(bool restore_function_code) {
base::LockGuard<base::Mutex> access_output_queue_(&output_queue_mutex_);
OptimizedCompileJob* job;
while (output_queue_.Dequeue(&job)) {
// OSR jobs are dealt with separately.
@ -218,12 +242,20 @@ void OptimizingCompilerThread::FlushOsrBuffer(bool restore_function_code) {
void OptimizingCompilerThread::Flush() {
DCHECK(!IsOptimizerThread());
base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(FLUSH));
if (FLAG_block_concurrent_recompilation) Unblock();
if (!job_based_recompilation_) {
input_queue_semaphore_.Signal();
stop_semaphore_.Wait();
bool block = true;
if (job_based_recompilation_) {
base::LockGuard<base::RecursiveMutex> lock(&task_count_mutex_);
block = task_count_ > 0 || blocked_jobs_ > 0;
if (block) {
base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(FLUSH));
}
if (FLAG_block_concurrent_recompilation) Unblock();
} else {
base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(FLUSH));
if (FLAG_block_concurrent_recompilation) Unblock();
}
if (!job_based_recompilation_) input_queue_semaphore_.Signal();
if (block) stop_semaphore_.Wait();
FlushOutputQueue(true);
if (FLAG_concurrent_osr) FlushOsrBuffer(true);
if (tracing_enabled_) {
@ -234,25 +266,25 @@ void OptimizingCompilerThread::Flush() {
void OptimizingCompilerThread::Stop() {
DCHECK(!IsOptimizerThread());
base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(STOP));
if (FLAG_block_concurrent_recompilation) Unblock();
if (!job_based_recompilation_) {
input_queue_semaphore_.Signal();
stop_semaphore_.Wait();
}
bool block = true;
if (job_based_recompilation_) {
while (true) {
{
base::LockGuard<base::Mutex> access_input_queue(&input_queue_mutex_);
if (!input_queue_length_) break;
}
input_queue_semaphore_.Wait();
base::LockGuard<base::RecursiveMutex> lock(&task_count_mutex_);
block = task_count_ > 0 || blocked_jobs_ > 0;
if (block) {
base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(FLUSH));
}
} else if (FLAG_concurrent_recompilation_delay != 0) {
if (FLAG_block_concurrent_recompilation) Unblock();
} else {
base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(STOP));
if (FLAG_block_concurrent_recompilation) Unblock();
}
if (!job_based_recompilation_) input_queue_semaphore_.Signal();
if (block) stop_semaphore_.Wait();
if (recompilation_delay_ != 0) {
// At this point the optimizing compiler thread's event loop has stopped.
// There is no need for a mutex when reading input_queue_length_.
while (input_queue_length_ > 0) CompileNext();
while (input_queue_length_ > 0) CompileNext(NextInput());
InstallOptimizedFunctions();
} else {
FlushInputQueue(false);
@ -263,6 +295,7 @@ void OptimizingCompilerThread::Stop() {
if (tracing_enabled_) {
double percentage = time_spent_compiling_.PercentOf(time_spent_total_);
if (job_based_recompilation_) percentage = 100.0;
PrintF(" ** Compiler thread did %.2f%% useful work\n", percentage);
}
@ -333,11 +366,13 @@ void OptimizingCompilerThread::QueueForOptimization(OptimizedCompileJob* job) {
input_queue_[InputQueueIndex(input_queue_length_)] = job;
input_queue_length_++;
}
if (job_based_recompilation_) {
V8::GetCurrentPlatform()->CallOnBackgroundThread(
new CompileTask(isolate_, job), v8::Platform::kShortRunningTask);
} else if (FLAG_block_concurrent_recompilation) {
if (FLAG_block_concurrent_recompilation) {
blocked_jobs_++;
} else if (job_based_recompilation_) {
base::LockGuard<base::RecursiveMutex> lock(&task_count_mutex_);
++task_count_;
V8::GetCurrentPlatform()->CallOnBackgroundThread(
new CompileTask(isolate_), v8::Platform::kShortRunningTask);
} else {
input_queue_semaphore_.Signal();
}
@ -346,11 +381,17 @@ void OptimizingCompilerThread::QueueForOptimization(OptimizedCompileJob* job) {
void OptimizingCompilerThread::Unblock() {
DCHECK(!IsOptimizerThread());
if (job_based_recompilation_) {
return;
{
base::LockGuard<base::RecursiveMutex> lock(&task_count_mutex_);
task_count_ += blocked_jobs_;
}
while (blocked_jobs_ > 0) {
input_queue_semaphore_.Signal();
if (job_based_recompilation_) {
V8::GetCurrentPlatform()->CallOnBackgroundThread(
new CompileTask(isolate_), v8::Platform::kShortRunningTask);
} else {
input_queue_semaphore_.Signal();
}
blocked_jobs_--;
}
}

19
src/optimizing-compiler-thread.h
View File

@ -35,11 +35,13 @@ class OptimizingCompilerThread : public base::Thread {
input_queue_shift_(0),
osr_buffer_capacity_(FLAG_concurrent_recompilation_queue_length + 4),
osr_buffer_cursor_(0),
task_count_(0),
osr_hits_(0),
osr_attempts_(0),
blocked_jobs_(0),
tracing_enabled_(FLAG_trace_concurrent_recompilation),
job_based_recompilation_(FLAG_job_based_recompilation) {
job_based_recompilation_(FLAG_job_based_recompilation),
recompilation_delay_(FLAG_concurrent_recompilation_delay) {
base::NoBarrier_Store(&stop_thread_,
static_cast<base::AtomicWord>(CONTINUE));
input_queue_ = NewArray<OptimizedCompileJob*>(input_queue_capacity_);
@ -93,8 +95,8 @@ class OptimizingCompilerThread : public base::Thread {
void FlushInputQueue(bool restore_function_code);
void FlushOutputQueue(bool restore_function_code);
void FlushOsrBuffer(bool restore_function_code);
void CompileNext();
OptimizedCompileJob* NextInput();
void CompileNext(OptimizedCompileJob* job);
OptimizedCompileJob* NextInput(StopFlag* flag = NULL);
// Add a recompilation task for OSR to the cyclic buffer, awaiting OSR entry.
// Tasks evicted from the cyclic buffer are discarded.
@ -138,18 +140,27 @@ class OptimizingCompilerThread : public base::Thread {
base::TimeDelta time_spent_compiling_;
base::TimeDelta time_spent_total_;
int task_count_;
// TODO(jochen): This is currently a RecursiveMutex since both Flush/Stop and
// Unblock try to get it, but the former methods both can call Unblock. Once
// job based recompilation is on by default, and the dedicated thread can be
// removed, this should be refactored to not use a RecursiveMutex.
base::RecursiveMutex task_count_mutex_;
int osr_hits_;
int osr_attempts_;
int blocked_jobs_;
// Copies of FLAG_trace_concurrent_recompilation and
// Copies of FLAG_trace_concurrent_recompilation,
// FLAG_concurrent_recompilation_delay and
// FLAG_job_based_recompilation that will be used from the background thread.
//
// Since flags might get modified while the background thread is running, it
// is not safe to access them directly.
bool tracing_enabled_;
bool job_based_recompilation_;
int recompilation_delay_;
};
} } // namespace v8::internal