June 2008 - hotspot-gc-dev

Big GC with unknow reason
by Ken--＠newsgroupstats.hk 24 Jun '08

24 Jun '08

First of all, I dunno is it appropriate to ask gc tuning question here. Please forgive me if I post in wrong place. Well, I was chat with Sun GC Tuning Team long time ago and seek for gc tuning advise. The team was dismissed. Today, I google Jon Masamitsu and finally get here. :> So, my question is: Any idea why there was a big gc at 51789? We are using jdk1.6.0_04 on windows32 with this set of vm option: c:\progra~1\Java\jdk1.6.0_04\bin\java -server -verbose:gc -XX:+PrintGCDetails -Xloggc:itrade_gc_gc.log -Xms1024M -Xmx1612M -XX:NewSize=128M -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:SurvivorRatio=6 -XX:CMSInitiatingOccupancyFraction=80 -XX:TargetSurvivorRatio=90 -Dcom.sun.management.jmxremote.port=18000 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false 51789.930: [Full GC 51789.930: [CMS: 403366K->126465K(917504K), 19.1967956 secs] 430862K->126465K(1032192K), [CMS Perm : 23152K->23072K(23296K)], 19.1972027 secs] [Times: user=0.94 sys=0.17, real=19.19 secs] The heap is around 4x% full at that time and the machine has 8G physical memory. From the logs, it show that it spend 19.19 secs (real), what is user/sys/real? Any info about it? I guess the vm is spending many time on memory swapping but task mgr show that the peak is around 4G. Thanks and Regards, Ken http://www.nabble.com/file/p18085880/2008-06-24_155647.gif -- View this message in context: http://www.nabble.com/Big-GC-with-unknow-reason-tp18085880p18085880.html Sent from the OpenJDK Hotspot Garbage Collection mailing list archive at Nabble.com.

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JVM options to get full visibility on generation behavior and GC log analysis tools.
by Alex Aisinzon 23 Jun '08

23 Jun '08

All I spend much time analyzing the behavior of the various generations. Their optimal sizing provides good performance improvements. I have several questions: * I add the following parameters to get good GC logs: "-XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintHeapAtGC -XX:+PrintGCApplicationConcurrentTime -XX:+PrintGCApplicationStoppedTime". I wonder if some additional options are useful. By example, the timestamps only track time since the JVM was started. To correlate an incident with application time stamps, it would be much more useful to have those time stamps use regular dates (2008-06-17 11:58:11,23 by example). * I have not found a good tool to analyze these logs and have to do that analysis by hand. HPJTune (HP) and GCViewer (TagTraum) are sometimes good enough but does not work when using more refined GC options like Parallel New Garbage Collection.. PrintGCStats is a last one that I have not found very useful either. Are there other tools available that someone could recommend? In comparison, the IBM JDK provides a single GC output format by using the verbose:gc option. IBM provides some very good tools to analyze those logs. Thanks in advance for helping tuning the Sun JDK as well as possible. This is for Sun JDK 1.5. Alex Aisinzon _______________________________________________ hotspot-gc-use mailing list hotspot-gc-use(a)openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use

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hg: jdk7/hotspot-gc/hotspot: 15 new changesets
by john.coomes＠sun.com 20 Jun '08

20 Jun '08

Changeset: 6d13fcb3663f Author: kvn Date: 2008-06-13 14:49 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/6d13fcb3663f 6714404: Add UseStringCache switch to enable String caching under AggressiveOpts Summary: Poke String.stringCacheEnabled during vm initialization Reviewed-by: never ! src/share/vm/classfile/vmSymbols.hpp ! src/share/vm/runtime/globals.hpp ! src/share/vm/runtime/thread.cpp Changeset: 44a553b2809d Author: kvn Date: 2008-06-13 15:08 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/44a553b2809d 6714406: Node::dominates() does not always check for TOP Summary: Add missed checks for TOP and missed checks for non-dominating cases Reviewed-by: rasbold, jrose, never ! src/share/vm/opto/memnode.cpp ! src/share/vm/opto/node.cpp Changeset: abe7181cbe8a Author: xdono Date: 2008-06-10 10:22 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/abe7181cbe8a Added tag jdk7-b28 for changeset c14dab40ed9b ! .hgtags Changeset: 4f91c08b3e44 Author: trims Date: 2008-06-17 15:27 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/4f91c08b3e44 Merge Changeset: 6470a2a42f92 Author: xlu Date: 2008-06-10 16:39 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/6470a2a42f92 6647068: libjvm.so is not built PIC Summary: Remove the preferred base address built with libjvm.so and unified the PIC approach on Solaris & Linux. Reviewed-by: never, kamg Contributed-by: xiaobin.lu(a)sun.com ! make/defs.make ! make/linux/makefiles/gcc.make ! make/linux/makefiles/rules.make ! make/solaris/makefiles/rules.make Changeset: f139919897d2 Author: xlu Date: 2008-06-17 09:59 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/f139919897d2 6681796: hotspot build failure on gcc 4.2.x (ubuntu 8.04) w/ openjdk 6 Summary: Fixed the cast from char* to const char* and tried to use const char* as much as possible Reviewed-by: never, kamg Contributed-by: xiaobin.lu(a)sun.com ! src/os/linux/vm/jvm_linux.cpp ! src/os/linux/vm/os_linux.cpp ! src/os/linux/vm/os_linux.hpp Changeset: 66cdb30329a6 Author: blacklion Date: 2008-06-19 06:02 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/66cdb30329a6 Merge Changeset: 86658812ca35 Author: ohair Date: 2008-06-13 14:52 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/86658812ca35 6714043: Minor fix to SS12 makefile changes Reviewed-by: sspitsyn ! make/solaris/makefiles/jvmg.make Changeset: 81675a0d3c75 Author: ohair Date: 2008-06-13 14:53 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/81675a0d3c75 Merge Changeset: 05d7b04bda37 Author: dcubed Date: 2008-06-14 21:53 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/05d7b04bda37 Merge Changeset: d6c28083ace6 Author: dcubed Date: 2008-06-16 13:38 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/d6c28083ace6 Merge Changeset: dfedd0e7fa9c Author: dcubed Date: 2008-06-17 09:33 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/dfedd0e7fa9c Merge Changeset: f20b3fcbb16f Author: dcubed Date: 2008-06-19 09:59 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/f20b3fcbb16f Merge Changeset: e619218327a7 Author: trims Date: 2008-06-20 11:47 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/e619218327a7 6717462: Update build number for HS14 B01 Summary: Change Hotspot version and build number for opening of HS14 Reviewed-by: jcoomes ! make/hotspot_version Changeset: 337e0e51cd6b Author: jcoomes Date: 2008-06-20 13:59 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/337e0e51cd6b Merge

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hg: jdk7/hotspot-gc/hotspot: 6676016: ParallelOldGC leaks memory
by john.coomes＠sun.com 19 Jun '08

19 Jun '08

Changeset: 05712c37c828 Author: jcoomes Date: 2008-06-18 18:36 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/05712c37c828 6676016: ParallelOldGC leaks memory Summary: ensure that GCTask threads release resource and handle memory Reviewed-by: jmasa, chrisphi ! src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp

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hg: jdk7/hotspot-gc/hotspot: 2 new changesets
by jon.masamitsu＠sun.com 12 Jun '08

12 Jun '08

Changeset: 35ca13d63fe8 Author: jmasa Date: 2008-06-10 07:26 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/35ca13d63fe8 6688799: Second fix for Guarantee failure "Unexpected dirty card found" Summary: Expand cardtable without committing over existing regions. Reviewed-by: apetrusenko ! src/share/vm/memory/cardTableModRefBS.cpp Changeset: 4fab66d72627 Author: jmasa Date: 2008-06-12 14:23 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/4fab66d72627 Merge

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hg: jdk7/hotspot-gc/hotspot: 40 new changesets
by john.coomes＠sun.com 10 Jun '08

10 Jun '08

Changeset: 24706b95d959 Author: xdono Date: 2008-04-24 12:12 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/24706b95d959 Added tag jdk7-b26 for changeset ad0b851458ff ! .hgtags Changeset: c70a245cad3a Author: dcubed Date: 2008-05-09 08:55 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/c70a245cad3a 6670684: 4/5 SA command universe did not print out CMS space information Summary: Forward port of Yumin's fix for 6670684 from HSX-11; Yumin verified the port was correct. Reviewed-by: dcubed ! agent/make/Makefile ! agent/src/share/classes/sun/jvm/hotspot/HSDB.java ! agent/src/share/classes/sun/jvm/hotspot/SALauncherLoader.java ! agent/src/share/classes/sun/jvm/hotspot/bugspot/Main.java ! agent/src/share/classes/sun/jvm/hotspot/jdi/SAJDIClassLoader.java + agent/src/share/classes/sun/jvm/hotspot/memory/BinaryTreeDictionary.java ! agent/src/share/classes/sun/jvm/hotspot/memory/CompactibleFreeListSpace.java ! agent/src/share/classes/sun/jvm/hotspot/memory/DefNewGeneration.java + agent/src/share/classes/sun/jvm/hotspot/memory/FreeList.java + agent/src/share/classes/sun/jvm/hotspot/memory/LinearAllocBlock.java ! agent/src/share/classes/sun/jvm/hotspot/ui/AnnotatedMemoryPanel.java ! agent/src/share/classes/sun/jvm/hotspot/ui/CommandProcessorPanel.java ! agent/src/share/classes/sun/jvm/hotspot/ui/DebuggerConsolePanel.java ! agent/src/share/classes/sun/jvm/hotspot/ui/HighPrecisionJScrollBar.java ! agent/src/share/classes/sun/jvm/hotspot/ui/JFrameWrapper.java ! agent/src/share/classes/sun/jvm/hotspot/ui/treetable/JTreeTable.java ! src/share/vm/gc_implementation/concurrentMarkSweep/binaryTreeDictionary.hpp ! src/share/vm/gc_implementation/concurrentMarkSweep/freeList.hpp ! src/share/vm/gc_implementation/concurrentMarkSweep/vmStructs_cms.hpp ! src/share/vm/runtime/vmStructs.cpp Changeset: 6ab92ec09f70 Author: dcubed Date: 2008-05-09 09:11 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/6ab92ec09f70 Merge Changeset: 09c2ba680204 Author: kvn Date: 2008-05-15 22:40 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/09c2ba680204 6700102: c2 assertion "counter_changed,"failed dependencies, but counter didn't change")" with AggressiveOpts Summary: Bytecode Escape Analyzer does not have the check for the case described in 6389127. Reviewed-by: never ! src/share/vm/ci/bcEscapeAnalyzer.cpp Changeset: 723be81c1212 Author: kvn Date: 2008-05-15 22:43 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/723be81c1212 6701887: JDK7 server VM in endless loop in Node::dominates Summary: The method Node::dominates loops in the dead code which does not have a Region node. Reviewed-by: jrose, never ! src/share/vm/opto/c2_globals.hpp ! src/share/vm/opto/memnode.cpp ! src/share/vm/opto/node.cpp Changeset: 5bba3366a9a2 Author: dcubed Date: 2008-05-16 13:42 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/5bba3366a9a2 Merge ! agent/src/share/classes/sun/jvm/hotspot/HSDB.java ! src/share/vm/runtime/vmStructs.cpp Changeset: a3e5744fafda Author: dcubed Date: 2008-05-20 09:47 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/a3e5744fafda Merge Changeset: a49545cab84a Author: ohair Date: 2008-05-27 09:47 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/a49545cab84a 6563752: Build and test JDK7 with Sun Studio 12 Express compilers (prep makefiles) Summary: Allows for building with SS12, no longer requires SS11, warns if not SS11 for now. Once SS12 is validated and performance measurements look ok, SS12 will be the validated compiler. Reviewed-by: sspitsyn, ikrylov ! make/jprt.config ! make/solaris/makefiles/debug.make ! make/solaris/makefiles/dtrace.make ! make/solaris/makefiles/fastdebug.make ! make/solaris/makefiles/jvmg.make ! make/solaris/makefiles/optimized.make ! make/solaris/makefiles/product.make ! make/solaris/makefiles/sparc.make ! make/solaris/makefiles/sparcWorks.make ! make/solaris/makefiles/sparcv9.make Changeset: af059c49e677 Author: ohair Date: 2008-05-28 10:16 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/af059c49e677 6703308: Fix jprt.properties to allow for jdk6 and jdk7 builds Summary: Allows for jprt submit -release option to select jdk version and proper build targets. Reviewed-by: jcoomes ! make/jprt.properties Changeset: 27f13876aef3 Author: iveresov Date: 2008-05-30 03:53 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/27f13876aef3 Merge Changeset: 8aa010f60e0f Author: rasbold Date: 2008-05-20 06:32 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/8aa010f60e0f Merge Changeset: 885ed790ecf0 Author: kvn Date: 2008-05-21 10:45 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/885ed790ecf0 6695810: null oop passed to encode_heap_oop_not_null Summary: fix several problems in C2 related to Escape Analysis and Compressed Oops. Reviewed-by: never, jrose ! src/cpu/sparc/vm/sparc.ad ! src/cpu/x86/vm/x86_64.ad ! src/share/vm/opto/callnode.cpp ! src/share/vm/opto/cfgnode.cpp ! src/share/vm/opto/compile.cpp ! src/share/vm/opto/connode.cpp ! src/share/vm/opto/connode.hpp ! src/share/vm/opto/escape.cpp ! src/share/vm/opto/library_call.cpp ! src/share/vm/opto/macro.cpp ! src/share/vm/opto/matcher.cpp ! src/share/vm/opto/memnode.cpp ! src/share/vm/opto/memnode.hpp ! src/share/vm/opto/node.cpp ! src/share/vm/opto/output.cpp ! src/share/vm/opto/type.cpp ! src/share/vm/opto/type.hpp + test/compiler/6689060/Test.java + test/compiler/6695810/Test.java Changeset: c436414a719e Author: kvn Date: 2008-05-21 13:46 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/c436414a719e 6703890: Compressed Oops: add LoadNKlass node to generate narrow oops (32-bits) compare instructions Summary: Add LoadNKlass and CMoveN nodes, use CmpN and ConN nodes to generate narrow oops compare instructions. Reviewed-by: never, rasbold ! src/cpu/sparc/vm/assembler_sparc.cpp ! src/cpu/sparc/vm/assembler_sparc.hpp ! src/cpu/sparc/vm/relocInfo_sparc.cpp ! src/cpu/sparc/vm/relocInfo_sparc.hpp ! src/cpu/sparc/vm/sparc.ad ! src/cpu/x86/vm/assembler_x86_64.cpp ! src/cpu/x86/vm/assembler_x86_64.hpp ! src/cpu/x86/vm/relocInfo_x86.cpp ! src/cpu/x86/vm/relocInfo_x86.hpp ! src/cpu/x86/vm/x86_64.ad ! src/share/vm/adlc/forms.cpp ! src/share/vm/adlc/formssel.cpp ! src/share/vm/includeDB_core ! src/share/vm/opto/classes.hpp ! src/share/vm/opto/compile.cpp ! src/share/vm/opto/connode.cpp ! src/share/vm/opto/connode.hpp ! src/share/vm/opto/doCall.cpp ! src/share/vm/opto/escape.cpp ! src/share/vm/opto/graphKit.cpp ! src/share/vm/opto/lcm.cpp ! src/share/vm/opto/library_call.cpp ! src/share/vm/opto/loopopts.cpp ! src/share/vm/opto/matcher.cpp ! src/share/vm/opto/memnode.cpp ! src/share/vm/opto/memnode.hpp ! src/share/vm/opto/parse1.cpp ! src/share/vm/opto/parseHelper.cpp ! src/share/vm/runtime/globals.hpp Changeset: 437d03ea40b1 Author: kvn Date: 2008-05-21 16:31 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/437d03ea40b1 6703888: Compressed Oops: use the 32-bits gap after klass in a object Summary: Use the gap also for a narrow oop field and a boxing object value. Reviewed-by: coleenp, never ! src/cpu/sparc/vm/sharedRuntime_sparc.cpp ! src/cpu/sparc/vm/sparc.ad ! src/cpu/x86/vm/sharedRuntime_x86_32.cpp ! src/cpu/x86/vm/sharedRuntime_x86_64.cpp ! src/share/vm/ci/ciInstanceKlass.cpp ! src/share/vm/classfile/classFileParser.cpp ! src/share/vm/classfile/javaClasses.cpp ! src/share/vm/classfile/javaClasses.hpp ! src/share/vm/gc_implementation/includeDB_gc_shared ! src/share/vm/oops/arrayOop.hpp ! src/share/vm/oops/instanceKlass.hpp ! src/share/vm/oops/instanceKlassKlass.cpp ! src/share/vm/oops/instanceOop.hpp Changeset: aaa1137c5ef4 Author: sgoldman Date: 2008-05-28 12:42 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/aaa1137c5ef4 6707485: bytecodeInterpreterWithChecks.xsl is malformed Summary: xsl output tag not at top level Reviewed-by: never, kvn, rasbold Contributed-by: gnu_andrew(a)member.fsf.org ! src/share/vm/interpreter/bytecodeInterpreterWithChecks.xml ! src/share/vm/interpreter/bytecodeInterpreterWithChecks.xsl Changeset: feeb96a45707 Author: coleenp Date: 2008-05-28 21:06 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/feeb96a45707 6696264: assert("narrow oop can never be zero") for GCBasher & ParNewGC Summary: decouple set_klass() with zeroing the gap when compressed. Reviewed-by: kvn, ysr, jrose ! src/cpu/sparc/vm/assembler_sparc.cpp ! src/cpu/sparc/vm/assembler_sparc.hpp ! src/cpu/sparc/vm/templateTable_sparc.cpp ! src/cpu/x86/vm/assembler_x86_64.cpp ! src/cpu/x86/vm/assembler_x86_64.hpp ! src/cpu/x86/vm/templateTable_x86_64.cpp ! src/share/vm/gc_implementation/parNew/parNewGeneration.cpp ! src/share/vm/gc_interface/collectedHeap.inline.hpp ! src/share/vm/interpreter/bytecodeInterpreter.cpp ! src/share/vm/memory/space.cpp ! src/share/vm/oops/oop.hpp ! src/share/vm/oops/oop.inline.hpp Changeset: 7793bd37a336 Author: kvn Date: 2008-05-29 12:04 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/7793bd37a336 6705887: Compressed Oops: generate x64 addressing and implicit null checks with narrow oops Summary: Generate addresses and implicit null checks with narrow oops to avoid decoding. Reviewed-by: jrose, never ! src/cpu/x86/vm/assembler_x86_32.hpp ! src/cpu/x86/vm/assembler_x86_64.hpp ! src/cpu/x86/vm/x86_64.ad ! src/os_cpu/linux_x86/vm/assembler_linux_x86_32.cpp ! src/os_cpu/linux_x86/vm/assembler_linux_x86_64.cpp ! src/os_cpu/solaris_x86/vm/assembler_solaris_x86_32.cpp ! src/os_cpu/solaris_x86/vm/assembler_solaris_x86_64.cpp ! src/os_cpu/windows_x86/vm/assembler_windows_x86_32.cpp ! src/os_cpu/windows_x86/vm/assembler_windows_x86_64.cpp ! src/share/vm/opto/callnode.hpp ! src/share/vm/opto/chaitin.cpp ! src/share/vm/opto/compile.cpp ! src/share/vm/opto/connode.cpp ! src/share/vm/opto/connode.hpp ! src/share/vm/opto/escape.cpp ! src/share/vm/opto/macro.cpp ! src/share/vm/opto/matcher.cpp ! src/share/vm/opto/matcher.hpp ! src/share/vm/opto/memnode.cpp ! src/share/vm/opto/node.hpp Changeset: 9148c65abefc Author: rasbold Date: 2008-05-29 16:22 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/9148c65abefc 6695049: (coll) Create an x86 intrinsic for Arrays.equals Summary: Intrinsify java/util/Arrays.equals(char[], char[]) Reviewed-by: kvn, never ! src/cpu/x86/vm/x86_32.ad ! src/cpu/x86/vm/x86_64.ad ! src/share/vm/classfile/vmSymbols.hpp ! src/share/vm/opto/classes.hpp ! src/share/vm/opto/lcm.cpp ! src/share/vm/opto/library_call.cpp ! src/share/vm/opto/loopnode.cpp ! src/share/vm/opto/matcher.cpp ! src/share/vm/opto/memnode.cpp ! src/share/vm/opto/memnode.hpp ! src/share/vm/runtime/arguments.cpp ! src/share/vm/runtime/globals.hpp Changeset: 02cc988a9fdc Author: rasbold Date: 2008-05-30 07:22 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/02cc988a9fdc Merge Changeset: e3d2692f8442 Author: trims Date: 2008-05-20 19:50 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/e3d2692f8442 Merge Changeset: 0e13255adcb0 Author: trims Date: 2008-05-30 14:30 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/0e13255adcb0 Merge Changeset: c14dab40ed9b Author: xdono Date: 2008-05-22 09:37 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/c14dab40ed9b Added tag jdk7-b27 for changeset e3d2692f8442 ! .hgtags Changeset: 3e4b7b5b2b4b Author: trims Date: 2008-05-30 14:31 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/3e4b7b5b2b4b Merge Changeset: 9077d695a1b0 Author: trims Date: 2008-05-30 14:50 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/9077d695a1b0 6709213: Update Build number for HS13 b02 Summary: Bump up build number to 02 Reviewed-by: jcoomes ! make/hotspot_version Changeset: 510f98a80563 Author: rasbold Date: 2008-06-03 13:14 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/510f98a80563 6709972: runThese failed with assert(false,"bad AD file") Summary: guard AryEqNode construction with has_match_rule() test, set SpecialArraysEquals default off Reviewed-by: kvn, never ! src/share/vm/opto/library_call.cpp ! src/share/vm/runtime/globals.hpp Changeset: f2759c126e9d Author: rasbold Date: 2008-06-03 15:38 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/f2759c126e9d Merge Changeset: 6b648fefb395 Author: kamg Date: 2008-05-22 13:03 -0400 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/6b648fefb395 6705523: Fix for 6695506 will violate spec when used in JDK6 Summary: Make max classfile version number dependent on JDK version Reviewed-by: acorn, never ! src/cpu/sparc/vm/sharedRuntime_sparc.cpp ! src/share/vm/classfile/classFileParser.cpp ! src/share/vm/runtime/java.hpp Changeset: 2a8ec427fbe1 Author: kamg Date: 2008-05-29 14:06 -0400 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/2a8ec427fbe1 6706604: Copyright headers need to be changed to GPL. Summary: Update the copyrights Reviewed-by: ohair ! src/share/vm/interpreter/bytecodeInterpreterWithChecks.xml ! src/share/vm/interpreter/bytecodeInterpreterWithChecks.xsl ! test/compiler/6659207/Test.java ! test/compiler/6661247/Test.java ! test/compiler/6663621/IVTest.java Changeset: 6d172e3548cb Author: coleenp Date: 2008-06-05 17:02 -0400 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/6d172e3548cb 6695819: verify_oopx rax: broken oop in decode_heap_oop Summary: Code in gen_subtype_check was encoding rax as an oop on a path where rax was not an oop. Reviewed-by: never, kvn ! src/cpu/sparc/vm/assembler_sparc.cpp ! src/cpu/x86/vm/assembler_x86_64.cpp ! src/cpu/x86/vm/interp_masm_x86_64.cpp Changeset: 1f809e010142 Author: kamg Date: 2008-06-06 13:43 -0400 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/1f809e010142 Merge ! src/cpu/sparc/vm/assembler_sparc.cpp ! src/cpu/sparc/vm/sharedRuntime_sparc.cpp ! src/cpu/x86/vm/assembler_x86_64.cpp ! src/share/vm/classfile/classFileParser.cpp ! src/share/vm/interpreter/bytecodeInterpreterWithChecks.xml ! src/share/vm/interpreter/bytecodeInterpreterWithChecks.xsl Changeset: b9ebd46331d2 Author: kvn Date: 2008-06-04 14:03 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/b9ebd46331d2 6710654: SAJDI failures with Compressed Oops Summary: Use correct offset for the java.lang.Class _klass field in SA. Reviewed-by: jrose, never ! agent/src/share/classes/sun/jvm/hotspot/oops/OopUtilities.java Changeset: 823298b11afc Author: never Date: 2008-06-04 21:56 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/823298b11afc 6709165: Tests hang or misbahve with HS 13.0-b01 on solaris-sparcv9 Reviewed-by: kvn, jrose ! src/cpu/sparc/vm/sparc.ad Changeset: 44abbb0d4c18 Author: kvn Date: 2008-06-05 13:02 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/44abbb0d4c18 6709093: Compressed Oops: reduce size of compiled methods Summary: exclude UEP size from nmethod code size and use narrow klass oop to load prototype header. Reviewed-by: jrose, never ! src/cpu/sparc/vm/sparc.ad ! src/cpu/x86/vm/assembler_x86_64.cpp ! src/cpu/x86/vm/assembler_x86_64.hpp ! src/cpu/x86/vm/x86_64.ad ! src/share/vm/ci/ciMethod.cpp ! src/share/vm/opto/compile.cpp Changeset: d4dbd9f91680 Author: never Date: 2008-06-05 15:43 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/d4dbd9f91680 6711083: 64bit JVM crashes with Internal Error (type.cpp:763) - ShouldNotReachHere() with enabled COOPs Summary: Add NarrowOop to various xmeet routines Reviewed-by: kvn, sgoldman, jrose, rasbold ! src/share/vm/opto/type.cpp Changeset: 65fe2bd88839 Author: never Date: 2008-06-05 21:44 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/65fe2bd88839 6614100: EXCEPTION_ACCESS_VIOLATION while running Eclipse with 1.6.0_05-ea Reviewed-by: kvn, jrose, rasbold ! src/share/vm/opto/cfgnode.cpp Changeset: 8759d37f2524 Author: rasbold Date: 2008-06-06 11:47 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/8759d37f2524 6711701: disable compressed oops by default Summary: comment out code that turns on compressed oops Reviewed-by: never, phh ! src/share/vm/runtime/arguments.cpp Changeset: cf1821c649d9 Author: never Date: 2008-06-06 14:34 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/cf1821c649d9 Merge ! src/cpu/x86/vm/assembler_x86_64.cpp Changeset: 790e66e5fbac Author: coleenp Date: 2008-06-09 11:51 -0400 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/790e66e5fbac 6687581: Make CMS work with compressed oops Summary: Make FreeChunk read markword instead of LSB in _klass pointer to indicate that it's a FreeChunk for compressed oops. Reviewed-by: ysr, jmasa ! agent/src/share/classes/sun/jvm/hotspot/memory/CompactibleFreeListSpace.java ! agent/src/share/classes/sun/jvm/hotspot/memory/FreeChunk.java ! agent/src/share/classes/sun/jvm/hotspot/oops/Mark.java ! src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp ! src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp ! src/share/vm/gc_implementation/concurrentMarkSweep/freeBlockDictionary.hpp ! src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.cpp + src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.hpp ! src/share/vm/gc_implementation/concurrentMarkSweep/vmStructs_cms.hpp ! src/share/vm/gc_implementation/includeDB_gc_concurrentMarkSweep ! src/share/vm/oops/markOop.hpp ! src/share/vm/runtime/arguments.cpp ! src/share/vm/runtime/vmStructs.cpp Changeset: c0ecab83e6f3 Author: never Date: 2008-06-10 09:57 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/c0ecab83e6f3 Merge ! agent/src/share/classes/sun/jvm/hotspot/memory/CompactibleFreeListSpace.java ! src/share/vm/gc_implementation/concurrentMarkSweep/vmStructs_cms.hpp ! src/share/vm/runtime/vmStructs.cpp Changeset: 3ad4bacbcdbe Author: jcoomes Date: 2008-06-10 11:14 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/3ad4bacbcdbe Merge

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Breadth-first vs. Depth-first
by Martin Buchholz 10 Jun '08

10 Jun '08

JavaOne 2008 technical session PDFs are now available http://developers.sun.com/learning/javaoneonline/j1online.jsp?track=javase&… I enjoyed the discussion of breadh-first vs. depth-first GC copying in the JavaOne talk http://developers.sun.com/learning/javaoneonline/2008/pdf/TS-6434.pdf I'd like to suggest that this is a fruitful avenue for investigation, if hotspot engineers go further than simply switching whole-hog to depth-first. Profiling can find reference fields that are rarely dereferenced, and also ones that are likely to be dereferenced soon after the object itself is accessed. The former can be sequestered by the next copying GC into an unloved-object ghetto, while the latter can be stored contiguously with its parent object. Tricky to implement, and will certainly make GC slower, but might make the runtime of the mutator win big. And should be easier to implement than true object inlining. This ought to be very similar to the moving of dead or cold code fragments inside a method away from the hot code, that hotspot already does. Martin

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Re: GCOverheadLimit does not work ?
by Jon Masamitsu 09 Jun '08

09 Jun '08

David Tavoularis wrote: > Hi Jon, > > I would like to understand the computation of the percentage for the following Full GC example : > > 57587.994: [Full GC [PSYoungGen: 262144K->260978K(317184K)] [PSOldGen: 1310719K->1310719K(1310720K)] 1572863K->1571698K(1627904K) [PSPermGen: 17242K->17242K(20480K)] > Heap after GC : > PSYoungGen total 317184K, used 260978K (eden=262144K, from=OK (out of 55040K)) > PSOldGen total 1310720K, used 1310719K > PSPermGen total 20480K, used 17242K > > So the percentage is computed like this : ((317184K-260978K)+(1310720K-1310719K)+(20480K-17242K))/(317184K+1310720K+20480K)=59445K/1648384K=3.6% > 2% > If you want a definitive answer, please take a look at the sources. As I recall it, the perm gen is not counted so it's more like ((317184K-260978K)+(1310720K-1310719K)) / (317184K+1310720K) = 3.5% > The fix would be to compute it like this : ((262144K-260978K)+(1310720K-1310719K)+(20480K-17242K))/(317184K+1310720K+20480K)=4405K/1648384K=0.3% < 2% > I don't think that is always the right answer. If the survivor space is being used (i.e., objects are copied to it and collected from it), then it should be counted. In a young gen collection I would expect it to be counted all the time but there might be exceptions (e.g., an always tenure policy). When it's a full collection if it was being used it should be counted. I would expect it to be used when there are young gen collections occurring between full collections. If the collections are back-to-back full collections and the survivor space is not being used it might make sense to not count it. Sorry, it's just not clear to me. Counting it sometimes and not counting it others might surprise some users. > > > Is there a WA to this issue ? WA? > > 1. Is is possible to change by property the percentage from 2% to 5% ? -XX:GCHeapFreeLimit=5 > > 2. Maybe I could reduce the young size from 256MB to 128MB, and it will automatically reduce (?) the survivor from 55040K to 27520K ? And the percentage would be in this case 1.9% and the OOM would be triggered. > That might work but what is your goal? This feature is to just alert unsuspecting users to a very bad GC situation. You already know you have a problem here, right? _______________________________________________ hotspot-gc-use mailing list hotspot-gc-use(a)openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use

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Re: GCOverheadLimit does not work ?
by Peter B. Kessler 09 Jun '08

09 Jun '08

There's product(uintx, GCHeapFreeLimit, 2, \ "Minimum percentage of free space after a full GC before an " \ "OutOfMemoryError is thrown (used with GCTimeLimit)") \ But I have to say that I've never gotten it to behave the way I thought it worked. ... peter David Tavoularis wrote: > Hi Jon, > > I would like to understand the computation of the percentage for the following Full GC example : > > 57587.994: [Full GC [PSYoungGen: 262144K->260978K(317184K)] [PSOldGen: 1310719K->1310719K(1310720K)] 1572863K->1571698K(1627904K) [PSPermGen: 17242K->17242K(20480K)] > Heap after GC : > PSYoungGen total 317184K, used 260978K (eden=262144K, from=OK (out of 55040K)) > PSOldGen total 1310720K, used 1310719K > PSPermGen total 20480K, used 17242K > > So the percentage is computed like this : ((317184K-260978K)+(1310720K-1310719K)+(20480K-17242K))/(317184K+1310720K+20480K)=59445K/1648384K=3.6% > 2% > > The fix would be to compute it like this : ((262144K-260978K)+(1310720K-1310719K)+(20480K-17242K))/(317184K+1310720K+20480K)=4405K/1648384K=0.3% < 2% > > > > Is there a WA to this issue ? > > 1. Is is possible to change by property the percentage from 2% to 5% ? > > 2. Maybe I could reduce the young size from 256MB to 128MB, and it will automatically reduce (?) the survivor from 55040K to 27520K ? And the percentage would be in this case 1.9% and the OOM would be triggered. > > > Thanks in advance for your explanations > _______________________________________________ hotspot-gc-use mailing list hotspot-gc-use(a)openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use

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hg: jdk7/hotspot-gc/hotspot: 6711930: NUMA allocator: ParOld can create a hole less than minimal object size in the lgrp chunk
by igor.veresov＠sun.com 09 Jun '08

09 Jun '08

Changeset: d1635bf93939 Author: iveresov Date: 2008-06-09 07:18 -0700 URL: http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/d1635bf93939 6711930: NUMA allocator: ParOld can create a hole less than minimal object size in the lgrp chunk Summary: The fix takes care of three issues that can create a hole less a minimal object in the lgrp chunk Reviewed-by: ysr, apetrusenko ! src/share/vm/gc_implementation/shared/immutableSpace.cpp ! src/share/vm/gc_implementation/shared/immutableSpace.hpp ! src/share/vm/gc_implementation/shared/mutableNUMASpace.cpp ! src/share/vm/gc_implementation/shared/mutableNUMASpace.hpp ! src/share/vm/gc_implementation/shared/mutableSpace.cpp ! src/share/vm/gc_implementation/shared/mutableSpace.hpp

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