What is JVM startup parameter: -XX:+UseNUMA?

Usage:

 This flag allows the use of NonUniform Memory Architecture (NUMA) if available.

Since:

Starting from JDK 6.

Examples:

This will instruct JVM to use NUMA if available:

-XX:+UseNUMA

Description:

Non-uniform memory access (NUMA) is a computer memory design used in multiprocessing, where the memory access time depends on the memory location relative to the processor. Under NUMA, a processor can access its own local memory faster than non-local memory (memory local to another processor or memory shared between processors). The benefits of NUMA are limited to particular workloads, notably on servers where the data is often associated strongly with certain tasks or users.

This flag enables performance optimization of an application on a machine with NonUniform Memory Architecture (NUMA) by increasing the application's use of lower latency memory. By default, this option is disabled and no optimization for NUMA is made. The option is available only when the parallel garbage collector is used (-XX:+UseParallelGC).

Default Value:

By default, this flag is disabled.

Arguments related:

UseNUMAInterleaving, UseParallelGC

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