<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>[209825] trunk/Source/JavaScriptCore</title>
</head>
<body>
<style type="text/css"><!--
#msg dl.meta { border: 1px #006 solid; background: #369; padding: 6px; color: #fff; }
#msg dl.meta dt { float: left; width: 6em; font-weight: bold; }
#msg dt:after { content:':';}
#msg dl, #msg dt, #msg ul, #msg li, #header, #footer, #logmsg { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; }
#msg dl a { font-weight: bold}
#msg dl a:link { color:#fc3; }
#msg dl a:active { color:#ff0; }
#msg dl a:visited { color:#cc6; }
h3 { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; font-weight: bold; }
#msg pre { overflow: auto; background: #ffc; border: 1px #fa0 solid; padding: 6px; }
#logmsg { background: #ffc; border: 1px #fa0 solid; padding: 1em 1em 0 1em; }
#logmsg p, #logmsg pre, #logmsg blockquote { margin: 0 0 1em 0; }
#logmsg p, #logmsg li, #logmsg dt, #logmsg dd { line-height: 14pt; }
#logmsg h1, #logmsg h2, #logmsg h3, #logmsg h4, #logmsg h5, #logmsg h6 { margin: .5em 0; }
#logmsg h1:first-child, #logmsg h2:first-child, #logmsg h3:first-child, #logmsg h4:first-child, #logmsg h5:first-child, #logmsg h6:first-child { margin-top: 0; }
#logmsg ul, #logmsg ol { padding: 0; list-style-position: inside; margin: 0 0 0 1em; }
#logmsg ul { text-indent: -1em; padding-left: 1em; }#logmsg ol { text-indent: -1.5em; padding-left: 1.5em; }
#logmsg > ul, #logmsg > ol { margin: 0 0 1em 0; }
#logmsg pre { background: #eee; padding: 1em; }
#logmsg blockquote { border: 1px solid #fa0; border-left-width: 10px; padding: 1em 1em 0 1em; background: white;}
#logmsg dl { margin: 0; }
#logmsg dt { font-weight: bold; }
#logmsg dd { margin: 0; padding: 0 0 0.5em 0; }
#logmsg dd:before { content:'\00bb';}
#logmsg table { border-spacing: 0px; border-collapse: collapse; border-top: 4px solid #fa0; border-bottom: 1px solid #fa0; background: #fff; }
#logmsg table th { text-align: left; font-weight: normal; padding: 0.2em 0.5em; border-top: 1px dotted #fa0; }
#logmsg table td { text-align: right; border-top: 1px dotted #fa0; padding: 0.2em 0.5em; }
#logmsg table thead th { text-align: center; border-bottom: 1px solid #fa0; }
#logmsg table th.Corner { text-align: left; }
#logmsg hr { border: none 0; border-top: 2px dashed #fa0; height: 1px; }
#header, #footer { color: #fff; background: #636; border: 1px #300 solid; padding: 6px; }
#patch { width: 100%; }
#patch h4 {font-family: verdana,arial,helvetica,sans-serif;font-size:10pt;padding:8px;background:#369;color:#fff;margin:0;}
#patch .propset h4, #patch .binary h4 {margin:0;}
#patch pre {padding:0;line-height:1.2em;margin:0;}
#patch .diff {width:100%;background:#eee;padding: 0 0 10px 0;overflow:auto;}
#patch .propset .diff, #patch .binary .diff {padding:10px 0;}
#patch span {display:block;padding:0 10px;}
#patch .modfile, #patch .addfile, #patch .delfile, #patch .propset, #patch .binary, #patch .copfile {border:1px solid #ccc;margin:10px 0;}
#patch ins {background:#dfd;text-decoration:none;display:block;padding:0 10px;}
#patch del {background:#fdd;text-decoration:none;display:block;padding:0 10px;}
#patch .lines, .info {color:#888;background:#fff;}
--></style>
<div id="msg">
<dl class="meta">
<dt>Revision</dt> <dd><a href="http://trac.webkit.org/projects/webkit/changeset/209825">209825</a></dd>
<dt>Author</dt> <dd>fpizlo@apple.com</dd>
<dt>Date</dt> <dd>2016-12-14 12:57:20 -0800 (Wed, 14 Dec 2016)</dd>
</dl>
<h3>Log Message</h3>
<pre>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:</pre>
<h3>Modified Paths</h3>
<ul>
<li><a href="#trunkSourceJavaScriptCoreChangeLog">trunk/Source/JavaScriptCore/ChangeLog</a></li>
<li><a href="#trunkSourceJavaScriptCoreheapHeapcpp">trunk/Source/JavaScriptCore/heap/Heap.cpp</a></li>
<li><a href="#trunkSourceJavaScriptCoreheapSlotVisitorcpp">trunk/Source/JavaScriptCore/heap/SlotVisitor.cpp</a></li>
<li><a href="#trunkSourceJavaScriptCoreruntimeOptionscpp">trunk/Source/JavaScriptCore/runtime/Options.cpp</a></li>
</ul>
</div>
<div id="patch">
<h3>Diff</h3>
<a id="trunkSourceJavaScriptCoreChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/ChangeLog (209824 => 209825)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/ChangeLog 2016-12-14 20:56:50 UTC (rev 209824)
+++ trunk/Source/JavaScriptCore/ChangeLog 2016-12-14 20:57:20 UTC (rev 209825)
</span><span class="lines">@@ -1,3 +1,19 @@
</span><ins>+2016-12-14 Filip Pizlo <fpizlo@apple.com>
+
+ 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:
+
</ins><span class="cx"> 2016-12-14 Mark Lam <mark.lam@apple.com>
</span><span class="cx">
</span><span class="cx"> BytecodeBasicBlock::computeImpl() should not keep iterating blocks if all jump targets have already been found.
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreheapHeapcpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/heap/Heap.cpp (209824 => 209825)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/heap/Heap.cpp 2016-12-14 20:56:50 UTC (rev 209824)
+++ trunk/Source/JavaScriptCore/heap/Heap.cpp 2016-12-14 20:57:20 UTC (rev 209825)
</span><span class="lines">@@ -661,17 +661,24 @@
</span><span class="cx"> do {
</span><span class="cx"> auto decision = scheduler.currentDecision();
</span><span class="cx"> if (decision.shouldBeResumed()) {
</span><del>- 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());
</del><ins>+ {
+ 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());
+ }
</ins><span class="cx"> }
</span><ins>+ if (Options::logGC()) {
+ Seconds wakeUpLatency = MonotonicTime::now() - decision.timeToStop();
+ if (wakeUpLatency >= 1_ms)
+ dataLog("wul!=", wakeUpLatency.milliseconds(), " ms ");
+ }
</ins><span class="cx"> } else
</span><span class="cx"> drainResult = m_collectorSlotVisitor->drainInParallel(decision.timeToResume());
</span><span class="cx"> } while (drainResult != SlotVisitor::SharedDrainResult::Done);
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreheapSlotVisitorcpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/heap/SlotVisitor.cpp (209824 => 209825)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/heap/SlotVisitor.cpp 2016-12-14 20:56:50 UTC (rev 209824)
+++ trunk/Source/JavaScriptCore/heap/SlotVisitor.cpp 2016-12-14 20:57:20 UTC (rev 209825)
</span><span class="lines">@@ -572,13 +572,19 @@
</span><span class="cx">
</span><span class="cx"> ASSERT(Options::numberOfGCMarkers());
</span><span class="cx">
</span><del>- if (!m_heap.hasHeapAccess() || m_heap.collectorBelievesThatTheWorldIsStopped()) {
</del><ins>+ if (Options::numberOfGCMarkers() < 4
+ || !m_heap.hasHeapAccess()
+ || m_heap.collectorBelievesThatTheWorldIsStopped()) {
</ins><span class="cx"> // This is an optimization over drainInParallel() when we have a concurrent mutator but
</span><span class="cx"> // otherwise it is not profitable.
</span><span class="cx"> return drainInParallel(timeout);
</span><span class="cx"> }
</span><ins>+
+ 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();
</ins><span class="cx">
</span><del>- LockHolder locker(m_heap.m_markingMutex);
</del><span class="cx"> for (;;) {
</span><span class="cx"> if (hasElapsed(timeout))
</span><span class="cx"> return SharedDrainResult::TimedOut;
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoreruntimeOptionscpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/runtime/Options.cpp (209824 => 209825)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/runtime/Options.cpp 2016-12-14 20:56:50 UTC (rev 209824)
+++ trunk/Source/JavaScriptCore/runtime/Options.cpp 2016-12-14 20:57:20 UTC (rev 209825)
</span><span class="lines">@@ -306,6 +306,15 @@
</span><span class="cx"> }
</span><span class="cx"> }
</span><span class="cx">
</span><ins>+static void overrideDefaults()
+{
+ if (WTF::numberOfProcessorCores() < 4) {
+ Options::maximumMutatorUtilization() = 0.6;
+ Options::concurrentGCMaxHeadroom() = 1.4;
+ Options::concurrentGCPeriodMS() = 10;
+ }
+}
+
</ins><span class="cx"> static void recomputeDependentOptions()
</span><span class="cx"> {
</span><span class="cx"> #if !defined(NDEBUG)
</span><span class="lines">@@ -435,6 +444,8 @@
</span><span class="cx"> name_##Default() = defaultValue_;
</span><span class="cx"> JSC_OPTIONS(FOR_EACH_OPTION)
</span><span class="cx"> #undef FOR_EACH_OPTION
</span><ins>+
+ overrideDefaults();
</ins><span class="cx">
</span><span class="cx"> // Allow environment vars to override options if applicable.
</span><span class="cx"> // The evn var should be the name of the option prefixed with
</span></span></pre>
</div>
</div>
</body>
</html>