v8/src/cpu-profiler.cc

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// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/v8.h"
#include "src/cpu-profiler-inl.h"
#include "src/compiler.h"
#include "src/deoptimizer.h"
#include "src/frames-inl.h"
#include "src/hashmap.h"
#include "src/log-inl.h"
#include "src/vm-state-inl.h"
#include "include/v8-profiler.h"
namespace v8 {
namespace internal {
static const int kProfilerStackSize = 64 * KB;
ProfilerEventsProcessor::ProfilerEventsProcessor(ProfileGenerator* generator,
Sampler* sampler,
base::TimeDelta period)
: Thread(Thread::Options("v8:ProfEvntProc", kProfilerStackSize)),
generator_(generator),
Support higher CPU profiler sampling rate on posix systems New flag is added that allows to specify CPU profiler sampling rate in microseconds as command line argument. It was tested to work fine with 100us interval(currently it is 1ms). Default values are kept the same as in the current implementation. The new implementation is enabled only on POSIX platforms which use signals to collect samples. Other platforms that pause thread being sampled are to follow. SIGPROF signals are now sent on the profiler event processor thread to make sure that the processing thread does fall far behind the sampling. The patch is based on the previous one that was rolled out in r13851. The main difference is that the circular queue is not modified for now. On Linux sampling for CPU profiler is initiated on the profiler event processor thread, other platforms to follow. CPU profiler continues to use SamplingCircularQueue, we will probably replace it with a single sample buffer when Mac and Win ports support profiling on the event processing thread. When --prof option is specified profiling is initiated either on the profiler event processor thread if CPU profiler is on or on the SignalSender thread as it used to be if no CPU profiles are being collected. ProfilerEventsProcessor::ProcessEventsAndDoSample now waits in a tight loop, processing collected samples until sampling interval expires. To save CPU resources I'm planning to change that to use nanosleep as only one sample is expected in the queue at any point. BUG=v8:2814 R=bmeurer@chromium.org Review URL: https://codereview.chromium.org/21101002 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16310 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-08-26 07:17:12 +00:00
sampler_(sampler),
running_(1),
period_(period),
last_code_event_id_(0),
last_processed_code_event_id_(0) {}
void ProfilerEventsProcessor::Enqueue(const CodeEventsContainer& event) {
event.generic.order = ++last_code_event_id_;
events_buffer_.Enqueue(event);
}
void ProfilerEventsProcessor::AddDeoptStack(Isolate* isolate, Address from,
int fp_to_sp_delta) {
TickSampleEventRecord record(last_code_event_id_);
RegisterState regs;
Address fp = isolate->c_entry_fp(isolate->thread_local_top());
regs.sp = fp - fp_to_sp_delta;
regs.fp = fp;
regs.pc = from;
record.sample.Init(isolate, regs, TickSample::kSkipCEntryFrame);
ticks_from_vm_buffer_.Enqueue(record);
}
void ProfilerEventsProcessor::AddCurrentStack(Isolate* isolate) {
TickSampleEventRecord record(last_code_event_id_);
RegisterState regs;
StackFrameIterator it(isolate);
if (!it.done()) {
StackFrame* frame = it.frame();
regs.sp = frame->sp();
regs.fp = frame->fp();
regs.pc = frame->pc();
}
record.sample.Init(isolate, regs, TickSample::kSkipCEntryFrame);
ticks_from_vm_buffer_.Enqueue(record);
}
void ProfilerEventsProcessor::StopSynchronously() {
if (!base::NoBarrier_AtomicExchange(&running_, 0)) return;
Join();
}
bool ProfilerEventsProcessor::ProcessCodeEvent() {
CodeEventsContainer record;
if (events_buffer_.Dequeue(&record)) {
switch (record.generic.type) {
#define PROFILER_TYPE_CASE(type, clss) \
case CodeEventRecord::type: \
record.clss##_.UpdateCodeMap(generator_->code_map()); \
break;
CODE_EVENTS_TYPE_LIST(PROFILER_TYPE_CASE)
#undef PROFILER_TYPE_CASE
default: return true; // Skip record.
}
last_processed_code_event_id_ = record.generic.order;
return true;
}
return false;
}
ProfilerEventsProcessor::SampleProcessingResult
ProfilerEventsProcessor::ProcessOneSample() {
if (!ticks_from_vm_buffer_.IsEmpty()
&& ticks_from_vm_buffer_.Peek()->order ==
last_processed_code_event_id_) {
TickSampleEventRecord record;
ticks_from_vm_buffer_.Dequeue(&record);
generator_->RecordTickSample(record.sample);
return OneSampleProcessed;
}
const TickSampleEventRecord* record = ticks_buffer_.Peek();
if (record == NULL) {
if (ticks_from_vm_buffer_.IsEmpty()) return NoSamplesInQueue;
return FoundSampleForNextCodeEvent;
}
if (record->order != last_processed_code_event_id_) {
return FoundSampleForNextCodeEvent;
}
generator_->RecordTickSample(record->sample);
ticks_buffer_.Remove();
return OneSampleProcessed;
Support higher CPU profiler sampling rate on posix systems New flag is added that allows to specify CPU profiler sampling rate in microseconds as command line argument. It was tested to work fine with 100us interval(currently it is 1ms). Default values are kept the same as in the current implementation. The new implementation is enabled only on POSIX platforms which use signals to collect samples. Other platforms that pause thread being sampled are to follow. SIGPROF signals are now sent on the profiler event processor thread to make sure that the processing thread does fall far behind the sampling. The patch is based on the previous one that was rolled out in r13851. The main difference is that the circular queue is not modified for now. On Linux sampling for CPU profiler is initiated on the profiler event processor thread, other platforms to follow. CPU profiler continues to use SamplingCircularQueue, we will probably replace it with a single sample buffer when Mac and Win ports support profiling on the event processing thread. When --prof option is specified profiling is initiated either on the profiler event processor thread if CPU profiler is on or on the SignalSender thread as it used to be if no CPU profiles are being collected. ProfilerEventsProcessor::ProcessEventsAndDoSample now waits in a tight loop, processing collected samples until sampling interval expires. To save CPU resources I'm planning to change that to use nanosleep as only one sample is expected in the queue at any point. BUG=v8:2814 R=bmeurer@chromium.org Review URL: https://codereview.chromium.org/21101002 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16310 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-08-26 07:17:12 +00:00
}
void ProfilerEventsProcessor::Run() {
while (!!base::NoBarrier_Load(&running_)) {
base::TimeTicks nextSampleTime =
base::TimeTicks::HighResolutionNow() + period_;
base::TimeTicks now;
SampleProcessingResult result;
// Keep processing existing events until we need to do next sample
// or the ticks buffer is empty.
do {
result = ProcessOneSample();
if (result == FoundSampleForNextCodeEvent) {
// All ticks of the current last_processed_code_event_id_ are
// processed, proceed to the next code event.
ProcessCodeEvent();
}
now = base::TimeTicks::HighResolutionNow();
} while (result != NoSamplesInQueue && now < nextSampleTime);
if (nextSampleTime > now) {
#if V8_OS_WIN
// Do not use Sleep on Windows as it is very imprecise.
// Could be up to 16ms jitter, which is unacceptable for the purpose.
while (base::TimeTicks::HighResolutionNow() < nextSampleTime) {
}
#else
base::OS::Sleep(nextSampleTime - now);
#endif
}
// Schedule next sample. sampler_ is NULL in tests.
if (sampler_) sampler_->DoSample();
}
// Process remaining tick events.
do {
SampleProcessingResult result;
do {
result = ProcessOneSample();
} while (result == OneSampleProcessed);
} while (ProcessCodeEvent());
}
void* ProfilerEventsProcessor::operator new(size_t size) {
return AlignedAlloc(size, V8_ALIGNOF(ProfilerEventsProcessor));
}
void ProfilerEventsProcessor::operator delete(void* ptr) {
AlignedFree(ptr);
}
int CpuProfiler::GetProfilesCount() {
// The count of profiles doesn't depend on a security token.
return profiles_->profiles()->length();
}
CpuProfile* CpuProfiler::GetProfile(int index) {
return profiles_->profiles()->at(index);
}
void CpuProfiler::DeleteAllProfiles() {
if (is_profiling_) StopProcessor();
ResetProfiles();
}
void CpuProfiler::DeleteProfile(CpuProfile* profile) {
profiles_->RemoveProfile(profile);
delete profile;
if (profiles_->profiles()->is_empty() && !is_profiling_) {
// If this was the last profile, clean up all accessory data as well.
ResetProfiles();
}
}
static bool FilterOutCodeCreateEvent(Logger::LogEventsAndTags tag) {
return FLAG_prof_browser_mode
&& (tag != Logger::CALLBACK_TAG
&& tag != Logger::FUNCTION_TAG
&& tag != Logger::LAZY_COMPILE_TAG
&& tag != Logger::REG_EXP_TAG
&& tag != Logger::SCRIPT_TAG);
}
void CpuProfiler::CallbackEvent(Name* name, Address entry_point) {
if (FilterOutCodeCreateEvent(Logger::CALLBACK_TAG)) return;
CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
rec->start = entry_point;
rec->entry = profiles_->NewCodeEntry(
Logger::CALLBACK_TAG,
profiles_->GetName(name));
rec->size = 1;
processor_->Enqueue(evt_rec);
}
void CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag,
Code* code,
const char* name) {
if (FilterOutCodeCreateEvent(tag)) return;
CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
rec->start = code->address();
The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers. During generation code and relocation info are generated simultaneously. When code generation is done you each code object has associated "relocation info". Relocation information lets V8 to mark interesting places in the generated code: the pointers that might need to be relocated (after garbage collection), correspondences between the machine program counter and source locations for stack walking. This patch: 1. Add more source positions info in reloc info to make it suitable for source level mapping. The amount of data should not be increased dramatically because (1) V8 already marks interesting places in the generated code and (2) V8 does not write redundant information (it writes a pair (pc_offset, pos) only if pos is changed and skips other). I measured it on Octane benchmark - for unoptimized code the number of source positions may achieve 2x ('lin_solve' from NavierStokes benchmark). 2. When a sample happens, CPU profiler finds a code object by pc, then use its reloc info to match the sample to a source line. If a source line is found that hit counter is increased by one for this line. 3. Add a new public V8 API to get the hit source lines by CDT CPU profiler. Note that it's expected a minor patch in Blink to pack the source level info in JSON to be shown. 4.Add a test that checks how the samples are distributed through source lines. It tests two cases: (1) relocation info created during code generation and (2) relocation info associated with precompiled function's version. Patch from Denis Pravdin <denis.pravdin@intel.com>; R=svenpanne@chromium.org, yurys@chromium.org Review URL: https://codereview.chromium.org/682143003 Patch from Weiliang <weiliang.lin@intel.com>. Cr-Commit-Position: refs/heads/master@{#25182} git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25182 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-11-06 09:16:34 +00:00
rec->entry = profiles_->NewCodeEntry(
tag, profiles_->GetFunctionName(name), CodeEntry::kEmptyNamePrefix,
CodeEntry::kEmptyResourceName, CpuProfileNode::kNoLineNumberInfo,
CpuProfileNode::kNoColumnNumberInfo, NULL, code->instruction_start());
rec->size = code->ExecutableSize();
processor_->Enqueue(evt_rec);
}
void CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag,
Code* code,
Name* name) {
if (FilterOutCodeCreateEvent(tag)) return;
CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
rec->start = code->address();
The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers. During generation code and relocation info are generated simultaneously. When code generation is done you each code object has associated "relocation info". Relocation information lets V8 to mark interesting places in the generated code: the pointers that might need to be relocated (after garbage collection), correspondences between the machine program counter and source locations for stack walking. This patch: 1. Add more source positions info in reloc info to make it suitable for source level mapping. The amount of data should not be increased dramatically because (1) V8 already marks interesting places in the generated code and (2) V8 does not write redundant information (it writes a pair (pc_offset, pos) only if pos is changed and skips other). I measured it on Octane benchmark - for unoptimized code the number of source positions may achieve 2x ('lin_solve' from NavierStokes benchmark). 2. When a sample happens, CPU profiler finds a code object by pc, then use its reloc info to match the sample to a source line. If a source line is found that hit counter is increased by one for this line. 3. Add a new public V8 API to get the hit source lines by CDT CPU profiler. Note that it's expected a minor patch in Blink to pack the source level info in JSON to be shown. 4.Add a test that checks how the samples are distributed through source lines. It tests two cases: (1) relocation info created during code generation and (2) relocation info associated with precompiled function's version. Patch from Denis Pravdin <denis.pravdin@intel.com>; R=svenpanne@chromium.org, yurys@chromium.org Review URL: https://codereview.chromium.org/682143003 Patch from Weiliang <weiliang.lin@intel.com>. Cr-Commit-Position: refs/heads/master@{#25182} git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25182 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-11-06 09:16:34 +00:00
rec->entry = profiles_->NewCodeEntry(
tag, profiles_->GetFunctionName(name), CodeEntry::kEmptyNamePrefix,
CodeEntry::kEmptyResourceName, CpuProfileNode::kNoLineNumberInfo,
CpuProfileNode::kNoColumnNumberInfo, NULL, code->instruction_start());
rec->size = code->ExecutableSize();
processor_->Enqueue(evt_rec);
}
void CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag, Code* code,
SharedFunctionInfo* shared,
CompilationInfo* info, Name* script_name) {
if (FilterOutCodeCreateEvent(tag)) return;
CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
rec->start = code->address();
rec->entry = profiles_->NewCodeEntry(
tag, profiles_->GetFunctionName(shared->DebugName()),
The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers. During generation code and relocation info are generated simultaneously. When code generation is done you each code object has associated "relocation info". Relocation information lets V8 to mark interesting places in the generated code: the pointers that might need to be relocated (after garbage collection), correspondences between the machine program counter and source locations for stack walking. This patch: 1. Add more source positions info in reloc info to make it suitable for source level mapping. The amount of data should not be increased dramatically because (1) V8 already marks interesting places in the generated code and (2) V8 does not write redundant information (it writes a pair (pc_offset, pos) only if pos is changed and skips other). I measured it on Octane benchmark - for unoptimized code the number of source positions may achieve 2x ('lin_solve' from NavierStokes benchmark). 2. When a sample happens, CPU profiler finds a code object by pc, then use its reloc info to match the sample to a source line. If a source line is found that hit counter is increased by one for this line. 3. Add a new public V8 API to get the hit source lines by CDT CPU profiler. Note that it's expected a minor patch in Blink to pack the source level info in JSON to be shown. 4.Add a test that checks how the samples are distributed through source lines. It tests two cases: (1) relocation info created during code generation and (2) relocation info associated with precompiled function's version. Patch from Denis Pravdin <denis.pravdin@intel.com>; R=svenpanne@chromium.org, yurys@chromium.org Review URL: https://codereview.chromium.org/682143003 Patch from Weiliang <weiliang.lin@intel.com>. Cr-Commit-Position: refs/heads/master@{#25182} git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25182 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-11-06 09:16:34 +00:00
CodeEntry::kEmptyNamePrefix, profiles_->GetName(script_name),
CpuProfileNode::kNoLineNumberInfo, CpuProfileNode::kNoColumnNumberInfo,
NULL, code->instruction_start());
if (info) {
rec->entry->set_no_frame_ranges(info->ReleaseNoFrameRanges());
rec->entry->set_inlined_function_infos(info->inlined_function_infos());
}
rec->entry->FillFunctionInfo(shared);
rec->size = code->ExecutableSize();
processor_->Enqueue(evt_rec);
}
void CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag, Code* code,
SharedFunctionInfo* shared,
CompilationInfo* info, Name* script_name,
int line, int column) {
if (FilterOutCodeCreateEvent(tag)) return;
CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
rec->start = code->address();
The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers. During generation code and relocation info are generated simultaneously. When code generation is done you each code object has associated "relocation info". Relocation information lets V8 to mark interesting places in the generated code: the pointers that might need to be relocated (after garbage collection), correspondences between the machine program counter and source locations for stack walking. This patch: 1. Add more source positions info in reloc info to make it suitable for source level mapping. The amount of data should not be increased dramatically because (1) V8 already marks interesting places in the generated code and (2) V8 does not write redundant information (it writes a pair (pc_offset, pos) only if pos is changed and skips other). I measured it on Octane benchmark - for unoptimized code the number of source positions may achieve 2x ('lin_solve' from NavierStokes benchmark). 2. When a sample happens, CPU profiler finds a code object by pc, then use its reloc info to match the sample to a source line. If a source line is found that hit counter is increased by one for this line. 3. Add a new public V8 API to get the hit source lines by CDT CPU profiler. Note that it's expected a minor patch in Blink to pack the source level info in JSON to be shown. 4.Add a test that checks how the samples are distributed through source lines. It tests two cases: (1) relocation info created during code generation and (2) relocation info associated with precompiled function's version. Patch from Denis Pravdin <denis.pravdin@intel.com>; R=svenpanne@chromium.org, yurys@chromium.org Review URL: https://codereview.chromium.org/682143003 Patch from Weiliang <weiliang.lin@intel.com>. Cr-Commit-Position: refs/heads/master@{#25182} git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25182 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-11-06 09:16:34 +00:00
Script* script = Script::cast(shared->script());
JITLineInfoTable* line_table = NULL;
if (script) {
line_table = new JITLineInfoTable();
for (RelocIterator it(code); !it.done(); it.next()) {
RelocInfo::Mode mode = it.rinfo()->rmode();
if (RelocInfo::IsPosition(mode)) {
int position = static_cast<int>(it.rinfo()->data());
if (position >= 0) {
int pc_offset = static_cast<int>(it.rinfo()->pc() - code->address());
int line_number = script->GetLineNumber(position) + 1;
line_table->SetPosition(pc_offset, line_number);
The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers. During generation code and relocation info are generated simultaneously. When code generation is done you each code object has associated "relocation info". Relocation information lets V8 to mark interesting places in the generated code: the pointers that might need to be relocated (after garbage collection), correspondences between the machine program counter and source locations for stack walking. This patch: 1. Add more source positions info in reloc info to make it suitable for source level mapping. The amount of data should not be increased dramatically because (1) V8 already marks interesting places in the generated code and (2) V8 does not write redundant information (it writes a pair (pc_offset, pos) only if pos is changed and skips other). I measured it on Octane benchmark - for unoptimized code the number of source positions may achieve 2x ('lin_solve' from NavierStokes benchmark). 2. When a sample happens, CPU profiler finds a code object by pc, then use its reloc info to match the sample to a source line. If a source line is found that hit counter is increased by one for this line. 3. Add a new public V8 API to get the hit source lines by CDT CPU profiler. Note that it's expected a minor patch in Blink to pack the source level info in JSON to be shown. 4.Add a test that checks how the samples are distributed through source lines. It tests two cases: (1) relocation info created during code generation and (2) relocation info associated with precompiled function's version. Patch from Denis Pravdin <denis.pravdin@intel.com>; R=svenpanne@chromium.org, yurys@chromium.org Review URL: https://codereview.chromium.org/682143003 Patch from Weiliang <weiliang.lin@intel.com>. Cr-Commit-Position: refs/heads/master@{#25182} git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25182 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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}
}
}
}
rec->entry = profiles_->NewCodeEntry(
tag, profiles_->GetFunctionName(shared->DebugName()),
CodeEntry::kEmptyNamePrefix, profiles_->GetName(script_name), line,
The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers. During generation code and relocation info are generated simultaneously. When code generation is done you each code object has associated "relocation info". Relocation information lets V8 to mark interesting places in the generated code: the pointers that might need to be relocated (after garbage collection), correspondences between the machine program counter and source locations for stack walking. This patch: 1. Add more source positions info in reloc info to make it suitable for source level mapping. The amount of data should not be increased dramatically because (1) V8 already marks interesting places in the generated code and (2) V8 does not write redundant information (it writes a pair (pc_offset, pos) only if pos is changed and skips other). I measured it on Octane benchmark - for unoptimized code the number of source positions may achieve 2x ('lin_solve' from NavierStokes benchmark). 2. When a sample happens, CPU profiler finds a code object by pc, then use its reloc info to match the sample to a source line. If a source line is found that hit counter is increased by one for this line. 3. Add a new public V8 API to get the hit source lines by CDT CPU profiler. Note that it's expected a minor patch in Blink to pack the source level info in JSON to be shown. 4.Add a test that checks how the samples are distributed through source lines. It tests two cases: (1) relocation info created during code generation and (2) relocation info associated with precompiled function's version. Patch from Denis Pravdin <denis.pravdin@intel.com>; R=svenpanne@chromium.org, yurys@chromium.org Review URL: https://codereview.chromium.org/682143003 Patch from Weiliang <weiliang.lin@intel.com>. Cr-Commit-Position: refs/heads/master@{#25182} git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25182 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-11-06 09:16:34 +00:00
column, line_table, code->instruction_start());
if (info) {
rec->entry->set_no_frame_ranges(info->ReleaseNoFrameRanges());
rec->entry->set_inlined_function_infos(info->inlined_function_infos());
}
rec->entry->FillFunctionInfo(shared);
rec->size = code->ExecutableSize();
processor_->Enqueue(evt_rec);
}
void CpuProfiler::CodeCreateEvent(Logger::LogEventsAndTags tag,
Code* code,
int args_count) {
if (FilterOutCodeCreateEvent(tag)) return;
CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
rec->start = code->address();
rec->entry = profiles_->NewCodeEntry(
The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers. During generation code and relocation info are generated simultaneously. When code generation is done you each code object has associated "relocation info". Relocation information lets V8 to mark interesting places in the generated code: the pointers that might need to be relocated (after garbage collection), correspondences between the machine program counter and source locations for stack walking. This patch: 1. Add more source positions info in reloc info to make it suitable for source level mapping. The amount of data should not be increased dramatically because (1) V8 already marks interesting places in the generated code and (2) V8 does not write redundant information (it writes a pair (pc_offset, pos) only if pos is changed and skips other). I measured it on Octane benchmark - for unoptimized code the number of source positions may achieve 2x ('lin_solve' from NavierStokes benchmark). 2. When a sample happens, CPU profiler finds a code object by pc, then use its reloc info to match the sample to a source line. If a source line is found that hit counter is increased by one for this line. 3. Add a new public V8 API to get the hit source lines by CDT CPU profiler. Note that it's expected a minor patch in Blink to pack the source level info in JSON to be shown. 4.Add a test that checks how the samples are distributed through source lines. It tests two cases: (1) relocation info created during code generation and (2) relocation info associated with precompiled function's version. Patch from Denis Pravdin <denis.pravdin@intel.com>; R=svenpanne@chromium.org, yurys@chromium.org Review URL: https://codereview.chromium.org/682143003 Patch from Weiliang <weiliang.lin@intel.com>. Cr-Commit-Position: refs/heads/master@{#25182} git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25182 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-11-06 09:16:34 +00:00
tag, profiles_->GetName(args_count), "args_count: ",
CodeEntry::kEmptyResourceName, CpuProfileNode::kNoLineNumberInfo,
CpuProfileNode::kNoColumnNumberInfo, NULL, code->instruction_start());
rec->size = code->ExecutableSize();
processor_->Enqueue(evt_rec);
}
void CpuProfiler::CodeMoveEvent(Address from, Address to) {
CodeEventsContainer evt_rec(CodeEventRecord::CODE_MOVE);
CodeMoveEventRecord* rec = &evt_rec.CodeMoveEventRecord_;
rec->from = from;
rec->to = to;
processor_->Enqueue(evt_rec);
}
void CpuProfiler::CodeDisableOptEvent(Code* code, SharedFunctionInfo* shared) {
CodeEventsContainer evt_rec(CodeEventRecord::CODE_DISABLE_OPT);
CodeDisableOptEventRecord* rec = &evt_rec.CodeDisableOptEventRecord_;
rec->start = code->address();
rec->bailout_reason = GetBailoutReason(shared->disable_optimization_reason());
processor_->Enqueue(evt_rec);
}
void CpuProfiler::CodeDeoptEvent(Code* code, Address pc, int fp_to_sp_delta) {
CodeEventsContainer evt_rec(CodeEventRecord::CODE_DEOPT);
CodeDeoptEventRecord* rec = &evt_rec.CodeDeoptEventRecord_;
Deoptimizer::DeoptInfo info = Deoptimizer::GetDeoptInfo(code, pc);
rec->start = code->address();
rec->deopt_reason = Deoptimizer::GetDeoptReason(info.deopt_reason);
rec->position = info.position;
rec->pc_offset = pc - code->instruction_start();
processor_->Enqueue(evt_rec);
processor_->AddDeoptStack(isolate_, pc, fp_to_sp_delta);
}
void CpuProfiler::CodeDeleteEvent(Address from) {
}
void CpuProfiler::GetterCallbackEvent(Name* name, Address entry_point) {
if (FilterOutCodeCreateEvent(Logger::CALLBACK_TAG)) return;
CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
rec->start = entry_point;
rec->entry = profiles_->NewCodeEntry(
Logger::CALLBACK_TAG,
profiles_->GetName(name),
"get ");
rec->size = 1;
processor_->Enqueue(evt_rec);
}
void CpuProfiler::RegExpCodeCreateEvent(Code* code, String* source) {
if (FilterOutCodeCreateEvent(Logger::REG_EXP_TAG)) return;
CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
rec->start = code->address();
rec->entry = profiles_->NewCodeEntry(
The idea behind of this solution is to use the existing "relocation info" instead of consumption the CodeLinePosition events emitted by the V8 compilers. During generation code and relocation info are generated simultaneously. When code generation is done you each code object has associated "relocation info". Relocation information lets V8 to mark interesting places in the generated code: the pointers that might need to be relocated (after garbage collection), correspondences between the machine program counter and source locations for stack walking. This patch: 1. Add more source positions info in reloc info to make it suitable for source level mapping. The amount of data should not be increased dramatically because (1) V8 already marks interesting places in the generated code and (2) V8 does not write redundant information (it writes a pair (pc_offset, pos) only if pos is changed and skips other). I measured it on Octane benchmark - for unoptimized code the number of source positions may achieve 2x ('lin_solve' from NavierStokes benchmark). 2. When a sample happens, CPU profiler finds a code object by pc, then use its reloc info to match the sample to a source line. If a source line is found that hit counter is increased by one for this line. 3. Add a new public V8 API to get the hit source lines by CDT CPU profiler. Note that it's expected a minor patch in Blink to pack the source level info in JSON to be shown. 4.Add a test that checks how the samples are distributed through source lines. It tests two cases: (1) relocation info created during code generation and (2) relocation info associated with precompiled function's version. Patch from Denis Pravdin <denis.pravdin@intel.com>; R=svenpanne@chromium.org, yurys@chromium.org Review URL: https://codereview.chromium.org/682143003 Patch from Weiliang <weiliang.lin@intel.com>. Cr-Commit-Position: refs/heads/master@{#25182} git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25182 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-11-06 09:16:34 +00:00
Logger::REG_EXP_TAG, profiles_->GetName(source), "RegExp: ",
CodeEntry::kEmptyResourceName, CpuProfileNode::kNoLineNumberInfo,
CpuProfileNode::kNoColumnNumberInfo, NULL, code->instruction_start());
rec->size = code->ExecutableSize();
processor_->Enqueue(evt_rec);
}
void CpuProfiler::SetterCallbackEvent(Name* name, Address entry_point) {
if (FilterOutCodeCreateEvent(Logger::CALLBACK_TAG)) return;
CodeEventsContainer evt_rec(CodeEventRecord::CODE_CREATION);
CodeCreateEventRecord* rec = &evt_rec.CodeCreateEventRecord_;
rec->start = entry_point;
rec->entry = profiles_->NewCodeEntry(
Logger::CALLBACK_TAG,
profiles_->GetName(name),
"set ");
rec->size = 1;
processor_->Enqueue(evt_rec);
}
CpuProfiler::CpuProfiler(Isolate* isolate)
: isolate_(isolate),
sampling_interval_(base::TimeDelta::FromMicroseconds(
FLAG_cpu_profiler_sampling_interval)),
profiles_(new CpuProfilesCollection(isolate->heap())),
generator_(NULL),
processor_(NULL),
is_profiling_(false) {
}
CpuProfiler::CpuProfiler(Isolate* isolate,
CpuProfilesCollection* test_profiles,
ProfileGenerator* test_generator,
ProfilerEventsProcessor* test_processor)
: isolate_(isolate),
sampling_interval_(base::TimeDelta::FromMicroseconds(
FLAG_cpu_profiler_sampling_interval)),
profiles_(test_profiles),
generator_(test_generator),
processor_(test_processor),
is_profiling_(false) {
}
CpuProfiler::~CpuProfiler() {
DCHECK(!is_profiling_);
delete profiles_;
}
void CpuProfiler::set_sampling_interval(base::TimeDelta value) {
DCHECK(!is_profiling_);
sampling_interval_ = value;
}
void CpuProfiler::ResetProfiles() {
delete profiles_;
profiles_ = new CpuProfilesCollection(isolate()->heap());
}
void CpuProfiler::StartProfiling(const char* title, bool record_samples) {
if (profiles_->StartProfiling(title, record_samples)) {
StartProcessorIfNotStarted();
}
}
void CpuProfiler::StartProfiling(String* title, bool record_samples) {
StartProfiling(profiles_->GetName(title), record_samples);
}
void CpuProfiler::StartProcessorIfNotStarted() {
if (processor_ != NULL) {
processor_->AddCurrentStack(isolate_);
return;
}
Logger* logger = isolate_->logger();
// Disable logging when using the new implementation.
saved_is_logging_ = logger->is_logging_;
logger->is_logging_ = false;
generator_ = new ProfileGenerator(profiles_);
Sampler* sampler = logger->sampler();
processor_ = new ProfilerEventsProcessor(
generator_, sampler, sampling_interval_);
is_profiling_ = true;
// Enumerate stuff we already have in the heap.
DCHECK(isolate_->heap()->HasBeenSetUp());
if (!FLAG_prof_browser_mode) {
logger->LogCodeObjects();
}
logger->LogCompiledFunctions();
logger->LogAccessorCallbacks();
LogBuiltins();
// Enable stack sampling.
sampler->SetHasProcessingThread(true);
sampler->IncreaseProfilingDepth();
processor_->AddCurrentStack(isolate_);
processor_->StartSynchronously();
}
CpuProfile* CpuProfiler::StopProfiling(const char* title) {
if (!is_profiling_) return NULL;
StopProcessorIfLastProfile(title);
CpuProfile* result = profiles_->StopProfiling(title);
if (result != NULL) {
result->Print();
}
return result;
}
CpuProfile* CpuProfiler::StopProfiling(String* title) {
if (!is_profiling_) return NULL;
const char* profile_title = profiles_->GetName(title);
StopProcessorIfLastProfile(profile_title);
return profiles_->StopProfiling(profile_title);
}
void CpuProfiler::StopProcessorIfLastProfile(const char* title) {
if (profiles_->IsLastProfile(title)) StopProcessor();
}
void CpuProfiler::StopProcessor() {
Logger* logger = isolate_->logger();
Sampler* sampler = reinterpret_cast<Sampler*>(logger->ticker_);
is_profiling_ = false;
processor_->StopSynchronously();
delete processor_;
delete generator_;
processor_ = NULL;
generator_ = NULL;
sampler->SetHasProcessingThread(false);
sampler->DecreaseProfilingDepth();
logger->is_logging_ = saved_is_logging_;
}
void CpuProfiler::LogBuiltins() {
Builtins* builtins = isolate_->builtins();
DCHECK(builtins->is_initialized());
for (int i = 0; i < Builtins::builtin_count; i++) {
CodeEventsContainer evt_rec(CodeEventRecord::REPORT_BUILTIN);
ReportBuiltinEventRecord* rec = &evt_rec.ReportBuiltinEventRecord_;
Builtins::Name id = static_cast<Builtins::Name>(i);
rec->start = builtins->builtin(id)->address();
rec->builtin_id = id;
processor_->Enqueue(evt_rec);
}
}
} // namespace internal
} // namespace v8