On Windows applications" are allowed to use higher native priorities. Java priorities below NORM_PRIORITY" map to lower native priority values. On Solaris NORM_PRIORITY and above are mapped to normal native priority. VM chooses priorities that are appropriate for normal applications. Number of parallel threads parallel gc will useĠ : Normal. You should reevaluate the effects of this option with prior to deploying a new release of Java. Note: this option is experimental! The specific optimizations enabled by this option can change from release to release and even build to build. This is a good flag to try the JVM engineering team's latest performance tweaks for upcoming releases.
The changes grouped by this flag are minor changes to JVM runtime compiled code and not distinct performance features (such as BiasedLocking and ParallelOldGC). Turns on point performance optimizations that are expected to be on by default in upcoming releases. Use the Parallel Scavenge garbage collector Use the command line option -verbose:gc to see the resulting sizes of the heap. These statistics are used to make decisions regarding changes to the sizes of the young generation and tenured generation so as to best fit the behavior of the application.
Adaptive sizing keeps statistics about garbage collection times, allocation rates, and the free space in the heap after a collection. The size of the initial heap is calculated based on the size of the physical memory and attempts to make maximal use of the physical memory for the heap (i.e., the algorithms attempt to use heaps nearly as large as the total physical memory).Ī feature available with the throughput collector in the J2SE platform, version 1.4.1 and later releases is the use of adaptive sizing (-XX:+UseAdaptiveSizePolicy), which is on by default. The physical memory on the machines must be at least 256MB before AggressiveHeap can be used. With this option the throughput collector (-XX:+ UseParallelGC) is used along with adaptive sizing (-XX:+ UseAdaptiveSizePolicy). It was originally intended for machines with large amounts of memory and a large number of CPUs, but in the J2SE platform, version 1.4.1 and later it has shown itself to be useful even on four processor machines. The -XX:+AggressiveHeap option inspects the machine resources (size of memory and number of processors) and attempts to set various parameters to be optimal for long-running, memory allocation-intensive jobs. These explainations are from the articles listed below Xverify:none What the options/settings do?
If someone knows how to test and benchmark Eclipse startup and performance better I would be interested in learning how. I would note the ThreadPriortyPolicy as stated in the desciption in might cause performance degragation so do some testing with it. My simple test shows an improvement in times. The ini file can be error prone with returns and spaces. I changed my eclipse.ini file around after researching some JVM option settings.īefore modifying the eclipse.ini file please back it up. These settings are suggestions and you may need adjust them. I am not a JVM options expert, but I referenced several articles. I primarily use CFEclipse, Mylyn, and Subclipse but started using Flex and getting an OutOfMemoryException.