SDK/RTE 1.4.2.09 for Debian Linux on Intel Itanium Processors Release Notes

0|1 controls the printing of heap information:
• 0 Print only after each Old Generation GC or full GC.
• 1 (default) Print after every Scavenge and Old Generation GC or Full GC.
:file=[stdout|stderr|]<filename>] specifies output file
stdout directs output to standard output stream
stderr (default) directs output to standard error stream
<filename> file to which the output will be written
At every garbage collection, the following 20 fields are printed:
<GC: %1 %2 %3 %4 %5 %6 %7 %8 %9 %10 %11 %12 %13 %14 %15 %16 %17 %18 %19 %20 >
For a detailed explanation of the fields in the -Xverbosegc:help output, see the
-Xverbosegc option in the “HotSpot Technology Tools and Commands” section of
the HP-UX Programmer's Guide for Java 2 on the BSC at:.
http://www.hp.com/go/hpux-java-docs.
In addition, we recommend HP's tool HPjtune, which graphically displays information
contained in an Xverbosegc log. HPjtune is available free of charge from
https://h20392.www2.hp.com/portal/swdepot/
displayProductInfo.do?productNumber=HPJTUNE.
For documentation on the new garbage collectors, refer to "Tuning Garbage Collection
with the 1.4.2 Java Virtual Machine" at http://java.sun.com/docs/hotspot/gc1.4.2/
index.html.
-XX:+AggressiveHeap
(excerpt from http://java.sun.com/docs/hotspot/ism.html)
This option instructs the JVM to push memory use to the limit. It sets the overall heap
to around 3850MB, the memory management policy defers collection as long as possible,
and and some GC activity is done in parallel. Because this option sets heap size, do not
use the -Xms or -Xmx options in conjunction with -XX:+AggressiveHeap. Doing
so will cause the options to override each other's settings for heap size.
Because the -XX:+AggressiveHeap option has specific system requirements for
correct operation and may require privileged access to system configuration parameters,
it should be used with caution. We have found it to be useful for certain applications
that create a lot of short lived objects.
-XX:+AllowUserSignalHandlers
Iinstructs the JVM not to complain if the application installs signal handlers.
-XX:+DisableExplicitGC
Disables calls to System.gc(). The JVM still performs garbage collection when
necessary.
Usage documentation 9