Itanium 1.6.0_12 Release Notes

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About Itanium 1.6.0_12

Itanium 1.6.0_12 is a port of JDK 6 update 12 to the Itanium (64 bit) architecture platform.

The full internal version number for this update release is 1.6.0_12-b0404 (where "b" means "build"). The external version number is 6u12. Included in JDK 6u12 for Itanium (64 bit architecture) platform is version 14.0 of the Java HotSpot Server Virtual Machine.

The following JDK, JRE tools are not included in Itanium JDK, JRE 6u12 release:

• Java Plug-in
• Java Web Start
• Java Update
• JavaDB (JavaDB is included only into Linux self-extracting JDK distributive)
• Java VisualVM

Please refer to JDK tools and Utilities for JDK tools description.

Only offline installation is available for JDK, JRE 6u12.

Changes in Itanium 1.6.0_12

• See changes in 1.6.0_12 common for all platforms in Java SE 6 Update 12 Release Notes.
• Serviceability Agent on Linux

  The Serviceability Agent is included in Linux distributions of JDK 6u12 for Itanium only.

  Tools based on read-only subset of JDI API should work with Serviceability Agent on Linux Itanium. The JDK includes a set of such tools: jdb, jinfo, jmap, jstack.

  See known Serviceability Agent issues and limitations section for known bugs in the Seviceability Agent and possible workarounds.

  See also Serviceability components description provided by OpenJDK Serviceability Group.

• Performance improvements

  Itanium 1.6.0_12 contains a number of new features that have resulted in significant performance improvements:

  • Inclusion of control and data speculation optimizations into the global instruction scheduling framework. These optimizations are enabled by default when AggressiveOpts is enabled.
  • Optimized code sequences for floating point constants. This feature is also enabled when AggressiveOpts is enabled.
  • An additional optimized object allocation and initialization code sequence in C2 compiled methods.
  • An additional optimized code sequence for large switch constructs (i.e. those with many ‘case’ labels). This feature is enabled with the command line flag -XX:+UseJumpTables.
  • The following set of command line options are recommended for running high performance server applications:

    
    
    -XX:+AggressiveOpts                     
    -XX:+AggressiveHeap                     
    -XX:ParallelGCThreads=2                     
    -XX:MaxInlineSize=75                     
    -XX:FreqInlineSize=700                     
    -XX:InterpreterProfilePercentage=10                     
    -XX:CompileThreshold=20000                     
    -XX:OnStackReplacePercentage=80                     
    -XX:ReservedCodeCacheSize=128m                     
    -XX:PermSize=256m                     
    -XX:MaxPermSize=256m                     
    -XX:AllocatePrefetchStepSize=128                     
    -XX:AllocatePrefetchStyle=2                     
    -XX:AllocatePrefetchDistance=896                     
    -XX:BiasedLockingStartupDelay=500                     
    -Xmx, -Xms, -Xmn should have sufficiently large values. (For example, -Xms6600m 
    -Xmn5000m -Xmx6600m or -Xms20000m -Xmn18000m -Xmx20000m.)
    
    

Supported System Configurations

JDK, JRE Installation for Microsoft Windows (Itanium)

The installation procedure installs the JDK or JRE 6u12 but not the Java Plugin or Java Web Start (which are not available for 64-bit Windows) or public Java Runtime Environment (when JDK is installed).

To install, download jdk-6u12-windows-ia64.exe or jre-6u12-windows-ia64.exe file and then follow the 32-bit Windows JDK installation or 32-bit Windows JRE installation "Windows Offline Installation" instructions.

Note: If you have jdk/jre-6u12-ea-windows-ia64.exe installed on your computer please uninstall it before jdk/jre-6u12-windows-ia64.exe installation to avoid conflict.

JDK, JRE Installation for Linux (Itanium)

The installation procedure installs the JRE or JDK 6u12 but not the Java Plugin or Java Web Start (which are not available for 64-bit Linux) or the public Java Runtime Environment (when JDK is installed).

The JDK, JRE for Linux 64-bit comes bundled in two install formats - Linux self-extracting files jdk-6u12-linux-ia64.bin, jre-6u12-linux-ia64.bin and Linux RPM in self-extracting files jdk-6u12-linux-ia64-rpm.bin, jre-6u12-linux-ia64-rpm.bin.

To install, download necessary file and then follow the 32-bit Linux JDK installation or 32-bit Linux JRE installation instructions.

Note: If you have jdk/jre-6u12-ea-linux-ia64-rpm.bin installed on your computer please uninstall it before jdk/jre-6u12-linux-ia64-rpm.bin installation to avoid conflict.

Known installation issues

• On Linux systems (specifically, on SLES 9) *-rpm.bin installation can report dmidecode unaligned access:

  
  
  dmidecode(18485): unaligned access to 0x600000000000801a, ip=0x4000000000007390                   
  dmidecode(18485): unaligned access to 0x600000000000801e, ip=0x40000000000073a1                   
  dmidecode(18485): unaligned access to 0x6000000000008065, ip=0x4000000000003151                   
  dmidecode(18485): unaligned access to 0x60000000000080f7, ip=0x4000000000003151 
  

  The bundles install successfully. Message printing can be disabled by command 'prctl --unaligned=silent'.

  The message is a warning for the user that application (dmidecode) works inefficient from performance perspective. The issue is resolved in dmidecode 2.7.

• On Linux systems, when *-rpm.bin file is used for JDK (JRE) installation, JDK (JRE) of lower version can not be installed if on the same system JDK (JRE) of higher version is installed.

  For example, JDK (JRE) 6u11 can not be installed using jdk(jre)-6u11-linux-ia64-rpm.bin file if, on the same machine, JDK (JRE) 6u12 was previously installed using jdk(jre)-6u12-linux-ia64-rpm.bin.

  Installation reports:

  Preparing... ########################################### [100%] package jdk-1.6.0_12-fcs (which is newer than jdk-1.6.0_11-fcs) is already installed JDK (JRE) 6u11 is not installed.

  Workarounds are:

  • Un-install JDK (JRE) 6u12, then, install JDK (JRE) 6u11 using jdk(jre)-6u11-linux-ia64-rpm.bin, or
  • Install JDK (JRE) 6u11 using jdk(jre)-6u11-linux-ia64.bin file
  • If JDK (JRE) 6u12 was installed using jdk(jre)-6u12-linux-ia64.bin, installation of JRE (JDK) 6u11 using jre(jdk)-6u11-linux-ia64.bin passes successfully.
• On Windows systems after installation of JDK (or JRE) the registry key "HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Development Kit\1.6" (for JDK), "HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment\1.6" (for JRE) should contain value "JavaHome" with the full path name of the directory in which JDK (or JRE) of the highest version is installed.

  After installation of Itanium JDK (or JRE) 6u12, "JavaHome" contains the path to the last installed JDK (or JRE) instead of the path to the JDK (or JRE) of the highest installed version. After un-installation the value is removed.

  The workaround is to put the correct value to the Windows registry manually. See Deploying the JRE on Windows for more details about registry values.

• On Windows consecutive JDK/JRE installations/uninstallations can lead (very rare) to:

  Error 1334.The file 'javaw.exe' cannot be installed because the file cannot be found in cabinet file 'Data1.cab'. This could indicate a network error, an error reading from the CD-ROM, or a problem with this package

  or

  Internal Error 2356. Data1.cab

  The second case can block installation/uninstallation, as the installer reports that there is a suspended installation process. A reboot of the system helps. After reboot, please, uninstall the previously installed JDK/JRE. Confirm the message, if it appears:

  Error 1704.An installation for Java(TM) SE Runtime Environment 6 Update 12 is currently suspended. You must undo the changes made by that installation to continue. Do you want to undo those changes?

Known issues and limitations

• The JVM can intermittently crash with SIGILL on Linux RHEL4 Itanium when executed from an NFS mounted directory.

  This is a known bug in kernels of version less than 2.6.22. Processors older than Montecito (e.g. Madison, McKinley) are not affected.

  RHEL4 (Nahant Update 5), kernel 2.6.9-55.EL has this bug. In RHEL5.2(Tikanga), kernel 2.6.18-92.el5 the bug is fixed.

  Possible workarounds are:

  • Run java from a local directory.
  • Migrate to a newer kernel in which this bug is fixed, for example, to RHEL5.2 or RHEL4.6.
  • Apply patch linux-2.6-mm-ia64-flush-i-cache-before-set_pte.patch (from kernel-2.6.18-92.el5.src.rpm) to your kernel.

• The JVM can intermittently crash when executed on Montecito or Montvale microprocessors, SLES 9 (any SP) operating system with Hyper-Threading enabled. The crash is rare. It occurs due to issues in the OS kernel. Typically, the crash is caused by a SIGILL (si_errno=0, si_code=1 (ILL_ILLOPC)) signal.

  Workarounds are:

  • Disable Hyper-Threading either completely (in BIOS) or partially for JVM process only using 'taskset' utility.
  • Use SLES 10.

• The JVM can intermittently crash when executed with best performance options (see "Performance improvements") on Linux. The crash is extremely rare. It has been observed on RHEL 4, 5 two-CPU Madison machines with HugePages turned off. The symptom of the crash is a SIGSEGV signal raised in a CompilerThread. The workaround is to specify the -XX:-UseMachineModel option. The issue will be fixed in a future release.

• The JVM can intermittently crash on Windows 2003 Itanium platform when it is run from network drive. A workaround is to install the JRE on local disk. The problem disappears after installing "Windows Server 2003 Service Pack 2 for Itanium-based Systems"

• Serviceablity Agent (SA) issues:

  • SA can fail to show thread stack frames, instead it shows empty stack. Workaround: for running processes use JVMTI Agent.
  • SA can fail to show some local variables of stack frames, instead it throws unexpected exception (typically, NullPointerException or AssertionFailure). Workaround: run JVM with –XX:+FullSASupport option.
  • Sometimes SA can show incorrect values for Long and Double locals. Workaround: for running processes use JVMTI Agent.
  • SA can show incorrect code location in method on top of stack, shown location is not far from real. Workaround: for running processes use JVMTI Agent.
  • SA based tools can fail to attach to target JVM or core files. Workaround: try to attach once more.
  • jstack (experimental tool) does not print mixed mode (both Java and native C/C++ frames) stack trace when option -m is specified, exception with diagnostic "not yet implemented (debugger does not support CDebugger)!" is thrown. The reason is that CDebugger is not implemented on Itanium. Workaround: do not use -m option or use different tool.

• ALSA (Advanced Linux Sound Architecture, http://www.alsa-project.org/wiki/Main_Page) sound support is not included in this release.
• Java 6 does not support Sun PKCS#11 and SunMSCAPI providers for Windows 64-bit (see native security features availability in various operating systems in Leveraging Security in the Native Platform Using Java SE 6 Technology article). These providers are not a part of Java 6 for Windows Itanium. If necessary, one can use implementations of these providers offered by third parties.