Changeset 222871 in webkit for trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp

Timestamp:

Oct 4, 2017, 1:00:01 PM (8 years ago)

Author:

[email protected]

Message:

Add support for using Probe DFG OSR Exit behind a runtime flag.
​https://bugs.webkit.org/show_bug.cgi?id=177844
<rdar://problem/34801425>

Reviewed by Saam Barati.

Source/JavaScriptCore:

This is based on the code originally posted in ​https://bugs.webkit.org/show_bug.cgi?id=175144
(in r221774 and r221832) with some optimizations and bug fixes added. The probe
based DFG OSR Exit is only enabled if Options::useProbeOSRExit() is true. We're
landing this behind an option switch to make it easier to tune performance using
the probe based OSR exit.

• JavaScriptCore.xcodeproj/project.pbxproj:
• assembler/MacroAssembler.cpp:

(JSC::stdFunctionCallback):

• assembler/MacroAssemblerPrinter.cpp:

(JSC::Printer::printCallback):

• assembler/ProbeContext.cpp:

(JSC::Probe::executeProbe):
(JSC::Probe::flushDirtyStackPages):

• assembler/ProbeContext.h:

(JSC::Probe::Context::Context):
(JSC::Probe::Context::arg):

• assembler/ProbeFrame.h: Added.

(JSC::Probe::Frame::Frame):
(JSC::Probe::Frame::argument):
(JSC::Probe::Frame::operand):
(JSC::Probe::Frame::setArgument):
(JSC::Probe::Frame::setOperand):
(JSC::Probe::Frame::get):
(JSC::Probe::Frame::set):

• assembler/ProbeStack.cpp:

(JSC::Probe::Page::lowWatermarkFromVisitingDirtyChunks):
(JSC::Probe::Stack::Stack):
(JSC::Probe::Stack::lowWatermarkFromVisitingDirtyPages):

• assembler/ProbeStack.h:

(JSC::Probe::Stack::Stack):
(JSC::Probe::Stack::lowWatermark):
(JSC::Probe::Stack::set):
(JSC::Probe::Stack::savedStackPointer const):
(JSC::Probe::Stack::setSavedStackPointer):
(JSC::Probe::Stack::newStackPointer const): Deleted.
(JSC::Probe::Stack::setNewStackPointer): Deleted.

• bytecode/ArrayProfile.h:

(JSC::ArrayProfile::observeArrayMode):

• bytecode/CodeBlock.cpp:

(JSC::CodeBlock::updateOSRExitCounterAndCheckIfNeedToReoptimize):

• bytecode/CodeBlock.h:

(JSC::CodeBlock::addressOfOSRExitCounter): Deleted.

• bytecode/ExecutionCounter.h:

(JSC::ExecutionCounter::hasCrossedThreshold const):
(JSC::ExecutionCounter::setNewThresholdForOSRExit):

• bytecode/MethodOfGettingAValueProfile.cpp:

(JSC::MethodOfGettingAValueProfile::reportValue):

• bytecode/MethodOfGettingAValueProfile.h:
• dfg/DFGDriver.cpp:

(JSC::DFG::compileImpl):

• dfg/DFGJITCompiler.cpp:

(JSC::DFG::JITCompiler::linkOSRExits):
(JSC::DFG::JITCompiler::link):

• dfg/DFGOSRExit.cpp:

(JSC::DFG::jsValueFor):
(JSC::DFG::restoreCalleeSavesFor):
(JSC::DFG::saveCalleeSavesFor):
(JSC::DFG::restoreCalleeSavesFromVMEntryFrameCalleeSavesBuffer):
(JSC::DFG::copyCalleeSavesToVMEntryFrameCalleeSavesBuffer):
(JSC::DFG::saveOrCopyCalleeSavesFor):
(JSC::DFG::createDirectArgumentsDuringExit):
(JSC::DFG::createClonedArgumentsDuringExit):
(JSC::DFG::emitRestoreArguments):
(JSC::DFG::OSRExit::executeOSRExit):
(JSC::DFG::reifyInlinedCallFrames):
(JSC::DFG::adjustAndJumpToTarget):
(JSC::DFG::printOSRExit):

• dfg/DFGOSRExit.h:

(JSC::DFG::OSRExitState::OSRExitState):

• dfg/DFGThunks.cpp:

(JSC::DFG::osrExitThunkGenerator):

• dfg/DFGThunks.h:
• dfg/DFGVariableEventStream.cpp:

(JSC::DFG::tryToSetConstantRecovery):
(JSC::DFG::VariableEventStream::reconstruct const):
(JSC::DFG::VariableEventStream::tryToSetConstantRecovery const): Deleted.

• dfg/DFGVariableEventStream.h:
• profiler/ProfilerOSRExit.h:

(JSC::Profiler::OSRExit::incCount):

• runtime/JSCJSValue.h:
• runtime/JSCJSValueInlines.h:
• runtime/Options.h:

Tools:

Enable --useProbeOSrExit=true for dfg-eager and ftl-no-cjit-validate-sampling-profiler
test configurations.

• Scripts/run-jsc-stress-tests:

File:

• trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp

@@ -2321 +2321 @@
 }
 
+auto CodeBlock::updateOSRExitCounterAndCheckIfNeedToReoptimize(DFG::OSRExitState& exitState) -> OptimizeAction
+{
+    DFG::OSRExitBase& exit = exitState.exit;
+    if (!exitKindMayJettison(exit.m_kind)) {
+        // FIXME: We may want to notice that we're frequently exiting
+        // at an op_catch that we didn't compile an entrypoint for, and
+        // then trigger a reoptimization of this CodeBlock:
+        // https://bugs.webkit.org/show_bug.cgi?id=175842
+        return OptimizeAction::None;
+    }
+
+    exit.m_count++;
+    m_osrExitCounter++;
+
+    CodeBlock* baselineCodeBlock = exitState.baselineCodeBlock;
+    ASSERT(baselineCodeBlock == baselineAlternative());
+    if (UNLIKELY(baselineCodeBlock->jitExecuteCounter().hasCrossedThreshold()))
+        return OptimizeAction::ReoptimizeNow;
+
+    // We want to figure out if there's a possibility that we're in a loop. For the outermost
+    // code block in the inline stack, we handle this appropriately by having the loop OSR trigger
+    // check the exit count of the replacement of the CodeBlock from which we are OSRing. The
+    // problem is the inlined functions, which might also have loops, but whose baseline versions
+    // don't know where to look for the exit count. Figure out if those loops are severe enough
+    // that we had tried to OSR enter. If so, then we should use the loop reoptimization trigger.
+    // Otherwise, we should use the normal reoptimization trigger.
+
+    bool didTryToEnterInLoop = false;
+    for (InlineCallFrame* inlineCallFrame = exit.m_codeOrigin.inlineCallFrame; inlineCallFrame; inlineCallFrame = inlineCallFrame->directCaller.inlineCallFrame) {
+        if (inlineCallFrame->baselineCodeBlock->ownerScriptExecutable()->didTryToEnterInLoop()) {
+            didTryToEnterInLoop = true;
+            break;
+        }
+    }
+
+    uint32_t exitCountThreshold = didTryToEnterInLoop
+        ? exitCountThresholdForReoptimizationFromLoop()
+        : exitCountThresholdForReoptimization();
+
+    if (m_osrExitCounter > exitCountThreshold)
+        return OptimizeAction::ReoptimizeNow;
+
+    // Too few fails. Adjust the execution counter such that the target is to only optimize after a while.
+    baselineCodeBlock->m_jitExecuteCounter.setNewThresholdForOSRExit(exitState.activeThreshold, exitState.memoryUsageAdjustedThreshold);
+    return OptimizeAction::None;
+}
+
 void CodeBlock::optimizeNextInvocation()
 {