Title: [209825] trunk/Source/_javascript_Core
- Revision
- 209825
- Author
- [email protected]
- Date
- 2016-12-14 12:57:20 -0800 (Wed, 14 Dec 2016)
Log Message
Devices with fewer cores should use a more aggressive GC schedule by default
https://bugs.webkit.org/show_bug.cgi?id=165859
Reviewed by Mark Lam.
* heap/Heap.cpp:
(JSC::Heap::markToFixpoint): Log when we have an unexpected delay in wake-up.
* heap/SlotVisitor.cpp:
(JSC::SlotVisitor::drainInParallelPassively): Don't drain passively if there aren't many cores.
* runtime/Options.cpp:
(JSC::overrideDefaults): Change the heuristics if we have fewer cores.
(JSC::Options::initialize):
* runtime/Options.h:
Modified Paths
Diff
Modified: trunk/Source/_javascript_Core/ChangeLog (209824 => 209825)
--- trunk/Source/_javascript_Core/ChangeLog 2016-12-14 20:56:50 UTC (rev 209824)
+++ trunk/Source/_javascript_Core/ChangeLog 2016-12-14 20:57:20 UTC (rev 209825)
@@ -1,3 +1,19 @@
+2016-12-14 Filip Pizlo <[email protected]>
+
+ Devices with fewer cores should use a more aggressive GC schedule by default
+ https://bugs.webkit.org/show_bug.cgi?id=165859
+
+ Reviewed by Mark Lam.
+
+ * heap/Heap.cpp:
+ (JSC::Heap::markToFixpoint): Log when we have an unexpected delay in wake-up.
+ * heap/SlotVisitor.cpp:
+ (JSC::SlotVisitor::drainInParallelPassively): Don't drain passively if there aren't many cores.
+ * runtime/Options.cpp:
+ (JSC::overrideDefaults): Change the heuristics if we have fewer cores.
+ (JSC::Options::initialize):
+ * runtime/Options.h:
+
2016-12-14 Mark Lam <[email protected]>
BytecodeBasicBlock::computeImpl() should not keep iterating blocks if all jump targets have already been found.
Modified: trunk/Source/_javascript_Core/heap/Heap.cpp (209824 => 209825)
--- trunk/Source/_javascript_Core/heap/Heap.cpp 2016-12-14 20:56:50 UTC (rev 209824)
+++ trunk/Source/_javascript_Core/heap/Heap.cpp 2016-12-14 20:57:20 UTC (rev 209825)
@@ -661,17 +661,24 @@
do {
auto decision = scheduler.currentDecision();
if (decision.shouldBeResumed()) {
- ResumeTheWorldScope resumeTheWorldScope(*this);
- drainResult = m_collectorSlotVisitor->drainInParallelPassively(decision.timeToStop());
- if (drainResult == SlotVisitor::SharedDrainResult::Done) {
- // At this point we will stop. But maybe the scheduler does not want
- // that.
- Seconds scheduledIdle = decision.timeToStop() - MonotonicTime::now();
- // It's totally unclear what the value of collectPermittedIdleRatio
- // should be, other than it should be greater than 0. You could even
- // argue for it being greater than 1. We should tune it.
- sleep(scheduledIdle * Options::collectorPermittedIdleRatio());
+ {
+ ResumeTheWorldScope resumeTheWorldScope(*this);
+ drainResult = m_collectorSlotVisitor->drainInParallelPassively(decision.timeToStop());
+ if (drainResult == SlotVisitor::SharedDrainResult::Done) {
+ // At this point we will stop. But maybe the scheduler does not want
+ // that.
+ Seconds scheduledIdle = decision.timeToStop() - MonotonicTime::now();
+ // It's totally unclear what the value of collectPermittedIdleRatio
+ // should be, other than it should be greater than 0. You could even
+ // argue for it being greater than 1. We should tune it.
+ sleep(scheduledIdle * Options::collectorPermittedIdleRatio());
+ }
}
+ if (Options::logGC()) {
+ Seconds wakeUpLatency = MonotonicTime::now() - decision.timeToStop();
+ if (wakeUpLatency >= 1_ms)
+ dataLog("wul!=", wakeUpLatency.milliseconds(), " ms ");
+ }
} else
drainResult = m_collectorSlotVisitor->drainInParallel(decision.timeToResume());
} while (drainResult != SlotVisitor::SharedDrainResult::Done);
Modified: trunk/Source/_javascript_Core/heap/SlotVisitor.cpp (209824 => 209825)
--- trunk/Source/_javascript_Core/heap/SlotVisitor.cpp 2016-12-14 20:56:50 UTC (rev 209824)
+++ trunk/Source/_javascript_Core/heap/SlotVisitor.cpp 2016-12-14 20:57:20 UTC (rev 209825)
@@ -572,13 +572,19 @@
ASSERT(Options::numberOfGCMarkers());
- if (!m_heap.hasHeapAccess() || m_heap.collectorBelievesThatTheWorldIsStopped()) {
+ if (Options::numberOfGCMarkers() < 4
+ || !m_heap.hasHeapAccess()
+ || m_heap.collectorBelievesThatTheWorldIsStopped()) {
// This is an optimization over drainInParallel() when we have a concurrent mutator but
// otherwise it is not profitable.
return drainInParallel(timeout);
}
+
+ LockHolder locker(m_heap.m_markingMutex);
+ m_collectorStack.transferTo(*m_heap.m_sharedCollectorMarkStack);
+ m_mutatorStack.transferTo(*m_heap.m_sharedMutatorMarkStack);
+ m_heap.m_markingConditionVariable.notifyAll();
- LockHolder locker(m_heap.m_markingMutex);
for (;;) {
if (hasElapsed(timeout))
return SharedDrainResult::TimedOut;
Modified: trunk/Source/_javascript_Core/runtime/Options.cpp (209824 => 209825)
--- trunk/Source/_javascript_Core/runtime/Options.cpp 2016-12-14 20:56:50 UTC (rev 209824)
+++ trunk/Source/_javascript_Core/runtime/Options.cpp 2016-12-14 20:57:20 UTC (rev 209825)
@@ -306,6 +306,15 @@
}
}
+static void overrideDefaults()
+{
+ if (WTF::numberOfProcessorCores() < 4) {
+ Options::maximumMutatorUtilization() = 0.6;
+ Options::concurrentGCMaxHeadroom() = 1.4;
+ Options::concurrentGCPeriodMS() = 10;
+ }
+}
+
static void recomputeDependentOptions()
{
#if !defined(NDEBUG)
@@ -435,6 +444,8 @@
name_##Default() = defaultValue_;
JSC_OPTIONS(FOR_EACH_OPTION)
#undef FOR_EACH_OPTION
+
+ overrideDefaults();
// Allow environment vars to override options if applicable.
// The evn var should be the name of the option prefixed with
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