To avoid long intervals between taking samples due to processing all accumulated samples at once, the samples are processed one by one and we check if the sampling interval has elapsed after each step rather than after processing all the samples in the queue.
This is a modified version of r16549 whith a fix for test flakiness. The test flakiness introduced by the previous version of this changed was fixed by changing return type of ProfilerEventsProcessor::ProcessOneSample from bool to enum with 3 options. In the main profiling loop we decide that the next code event should be processed when sample with a greater ordinal number is encountered. When processing remaining samples we shouldn't wait for more samples and if the samples queue is empty we just process next code event.
BUG=v8:2814,v8:2871
R=bmeurer@chromium.org, loislo@chromium.org
Review URL: https://codereview.chromium.org/23455036
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16564 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
These classes are meant to replace OS::Ticks() and OS::TimeCurrentMillis(),
which are broken in several ways. The ElapsedTimer class implements a
stopwatch using TimeTicks::HighResNow() for high resolution, monotonic
timing.
Also fix the CpuProfile::GetStartTime() and CpuProfile::GetEndTime()
methods to actually return the time relative to the unix epoch as stated
in the documentation (previously that was relative to some arbitrary
point in time, i.e. boot time).
The previous Windows issues have been resolved, and we now use GetTickCount64()
on Windows Vista and later, falling back to timeGetTime() with rollover
protection for earlier Windows versions.
BUG=v8:2853
R=machenbach@chromium.org, yurys@chromium.org
Review URL: https://codereview.chromium.org/23490015
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16413 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
These classes are meant to replace OS::Ticks() and OS::TimeCurrentMillis(),
which are broken in several ways. The ElapsedTimer class implements a
stopwatch using TimeTicks::HighResNow() for high resolution, monotonic
timing.
Also fix the CpuProfile::GetStartTime() and CpuProfile::GetEndTime()
methods to actually return the time relative to the unix epoch as stated
in the documentation (previously that was relative to some arbitrary
point in time, i.e. boot time).
BUG=v8:2853
R=machenbach@chromium.org
Review URL: https://codereview.chromium.org/23469013
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16398 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
These classes are meant to replace OS::Ticks() and OS::TimeCurrentMillis(),
which are broken in several ways. The ElapsedTimer class implements a
stopwatch using TimeTicks::HighResNow() for high resolution, monotonic
timing.
Also fix the CpuProfile::GetStartTime() and CpuProfile::GetEndTime()
methods to actually return the time relative to the unix epoch as stated
in the documentation (previously that was relative to some arbitrary
point in time, i.e. boot time).
BUG=v8:2853
R=machenbach@chromium.org, yurys@chromium.org
Review URL: https://codereview.chromium.org/23295034
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16388 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
New abstract class CodeEventListener was created.
CodeEventLogger which is the base class for Jit, LowLevel
and CodeAddressMap loggers was inherited from CodeEventListener.
CodeAddressMap class was moved to serializer.cc because serializer is the only user for it. Actually it collects code names and pushes them to the standard log as SnapshotCodeNameEvent. So I extracted this code into separate function CodeNameEvent. It happens that this method works only when Serializer serializes an object. So I added direct log call there.
CodeEventLogger class declaration was moved to the header
because CodeAddressMap needs it.
The code for the nested class CodeEventLogger::NameBuffer was left in the cc file.
CpuProfiler now is inherit CodeEventListener but not used
the loggers infrastructure yet due to the complex initialization schema. I'd like to fix that in a separate cl.
BUG=none
TEST=current test set.
R=yangguo@chromium.org, yurys@chromium.org
Review URL: https://codereview.chromium.org/19724007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15911 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This change fixes data race described in the bug by adding Acquire_Load to SamplingCircularQueue::StartDequeue and Acquire_Store to SamplingCircularQueue::Enqueue.
Also the queue implementation imposed a constraint on the records it stored: the first AtomicWord in each record was a marker. For that purpose TickSampleEventRecord had filter field of type int. This approach is error prone, e.g. on x64 sizeof(AtomicWord) is 8 while sizeof(int) is 4. Moreover the queue needs such marker only at the beginning of chunk. I changed the queue so that it stores the marker explicitly as the first Cell in chunk and removed the filter field.
BUG=251218
R=loislo@chromium.org, yangguo@chromium.org
Review URL: https://codereview.chromium.org/19642002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15750 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
1) report line number even if a script has no resource_name (evals);
a) do that for already compiled functions in log.cc;
b) do that for fresh evals in compiler.cc;
2) Implement the test for LineNumbers and make it fast and stable, otherwise we have to wait for tick samples;
a) move processor_->Join() call into new Processor::StopSynchronously method;
b) Process all the CodeEvents even if we are stopping Processor thread;
c) make getters for generator and processor;
3) Fix the test for Jit that didn't expect line numbers;
4) Minor refactoring:
a) in ProcessTicks;
b) rename enqueue_order_ to last_code_event_id_ for better readability;
c) rename dequeue_order_ to last_processed_code_event_id_ and make it a member for better readability;
BUG=
TEST=test-profile-generator/LineNumber
R=jkummerow@chromium.org, yurys@chromium.org
Review URL: https://codereview.chromium.org/18058008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15530 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When current function is FunctionCall builtin we have no reliable way to determine its caller function (in many cases the top of the sampled stack contains address of the caller but sometimes it does not). Instead of dropping the sample or its two top frames we simply mark the caller frame as '(unresolved function)'. It seems like a better approach that dropping whole sample as knowing the top function and the rest of the stack the user should be able to figure out what the caller was.
This change adds builtin id to CodeEntry objects. It will be used later to add similar top frame analysis for FunctionApply and probably other builtins.
BUG=None
TBR=loislo@chromium.org
Review URL: https://codereview.chromium.org/18422003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15436 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When current function is FunctionCall builtin we have no reliable way to determine its caller function (in many cases the top of the sampled stack contains address of the caller but sometimes it does not). Instead of dropping the sample or its two top frames we simply mark the caller frame as '(unresolved function)'. It seems like a better approach that dropping whole sample as knowing the top function and the rest of the stack the user should be able to figure out what the caller was.
This change adds builtin id to CodeEntry objects. It will be used later to add similar top frame analysis for FunctionApply and probably other builtins.
BUG=None
R=jkummerow@chromium.org, loislo@chromium.org
Review URL: https://codereview.chromium.org/18316004
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15426 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The bodies of methods in ProfilerEventProcessor were moved into CpuProfiler.
Multiple NewCodeEntry methods in CpuProfilesCollection were replaced with one which
simply passes arguments to the CodeEntry constructor.
And CpuProfiler just calls this method when it needs a CodeEntry object.
This NewCodeEntry method is required because CpuProfilesCollection keeps ownership of CodeEntry objects.
BUG=255392
TEST=existing tests
R=yangguo@chromium.org, yurys@chromium.org
Review URL: https://codereview.chromium.org/18053004
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15405 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This change modifies code produced by BaseLoadStubCompiler::GenerateLoadCallback so that instead of calling AccessorGetter direcly it calls InvokeAccessorGetter which changes VM state and calls the actual callback. This way CPU profiler knows which external callback is being executed in this case. Indirect call happens only if CpuProfiler::is_profiling() is true.
This is exactly same change as r15116 with a build fix for test-api.cc
BUG=244580
TBR=danno@chromium.org
Review URL: https://codereview.chromium.org/16858013
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15135 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This reverts commit f323d984a73bab345c4eab5c1907552ccfa7ccaa.
Broke compilation on the bots with an error that doesn't occur locally:
CXX(target) /mnt/data/b/build/slave/v8-linux-debug/build/v8/out/Debug/obj.target/cctest/test/cctest/test-bignum-dtoa.o
../test/cctest/test-api.cc: In function ‘void FastReturnValueCallback(const v8::FunctionCallbackInfo<v8::Value>&) [with T = int]’:
../test/cctest/test-api.cc:1129: error: insufficient contextual information to determine type
../test/cctest/test-api.cc: In function ‘void FastReturnValueCallback(const v8::FunctionCallbackInfo<v8::Value>&) [with T = unsigned int]’:
../test/cctest/test-api.cc:1136: error: insufficient contextual information to determine type
../test/cctest/test-api.cc: In function ‘void FastReturnValueCallback(const v8::FunctionCallbackInfo<v8::Value>&) [with T = double]’:
../test/cctest/test-api.cc:1143: error: insufficient contextual information to determine type
../test/cctest/test-api.cc: In function ‘void FastReturnValueCallback(const v8::FunctionCallbackInfo<v8::Value>&) [with T = bool]’:
../test/cctest/test-api.cc:1150: error: insufficient contextual information to determine type
../test/cctest/test-api.cc: In function ‘void FastReturnValueCallback(const v8::FunctionCallbackInfo<v8::Value>&) [with T = void]’:
../test/cctest/test-api.cc:1157: error: insufficient contextual information to determine type
CXX(target) /mnt/data/b/build/slave/v8-linux-debug/build/v8/out/Debug/obj.target/cctest/test/cctest/test-circular-queue.o
BUG=None
TBR=svenpanne@chromium.org
Review URL: https://codereview.chromium.org/16838013
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15117 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Stack iterator takes return address based on the frame pointer (ebp) and detects JS frames based on value at fp + StandardFrameConstants::kMarkerOffset. So in order the iterator to work correctly this values should be already setup for the current function. Stack frame is constructed at the very beginning of JS function code and destroyed before return. If sample is taken before before the frame construction is completed or after it was destroyed the stack iterator will wrongly think that FP points at the current functions frame base and will skip callers frame. To avoid this we mark code ranges where stack frame doesn't exist and completely ignore such samples.
This fixes cctest/test-cpu-profiler/CollectCpuProfile flakiness.
BUG=v8:2628
R=jkummerow@chromium.org
Review URL: https://codereview.chromium.org/14253015
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14670 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
CPU profiler API is extended with methods that allow to retrieve individual samples from profile. Each sample is presented as a pointer to a node in the top-down profile tree. The samples will let us tie JS performance to time.
BUG=None
Review URL: https://codereview.chromium.org/12919002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13980 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Since symbols and strings share a common representation, most of this change is about consistently replacing 'String' with 'Name' in all places where property names are expected. In particular, no new logic at all is necessary for maps, property dictionaries, or transitions. :) The only places where an actual case distinction is needed have to do with generated type checks, and with conversions of names to strings (especially in logger and profiler).
Left in some TODOs wrt to the API: interceptors and native getters don't accept symbols as property names yet, because that would require extending the external v8.h.
(Baseline CL: https://codereview.chromium.org/12296026/)
R=verwaest@chromium.org,mstarzinger@chromium.org
BUG=v8:2158
Review URL: https://codereview.chromium.org/12330012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13811 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The patch is based on the previous one that was rolled out: https://code.google.com/p/v8/source/detail?r=12985
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 replave 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 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=v8:2364
Review URL: https://codereview.chromium.org/12321046
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13735 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- perform CPU profiler sampling in the sampler thread as we used to;
- skip sampling in the sampling thread if processing thread is running;
- only install SIGPROF handler when CPU profiling is enabled.
BUG=v8:2364
Review URL: https://codereview.chromium.org/11231002
Patch from Sergey Rogulenko <rogulenko@google.com> and Andrey Kosyakov <caseq@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12985 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
