Thursday, 12 November 2015
Using -Xgc:preferredHeapBase with -Xcompressedrefs
Saw this IBM Technote via Twitter: -
"Why does the JVM report a native out-of-memory (NOOM) when using compressed references? I am using a 64bit JVM and I clearly have plenty of memory left. How can I resolve this problem?"
The IBM JVM will automatically use compressed references when using a maximum heap size less than 25GB. This automated behavior was introduced in Java 626 SR5 and Java 7 SR4*. Compressed references (CR) decreases the size of Java objects making better use of available memory space. This better use of space results in improved JVM performance. *(Java 7 SR1 and later uses compressed references by default on z/OS)
Worth a read