How do I enable large page support for Java?

Solution Verified - Updated 7 Aug 2024

Environment

Sun JDK
OpenJDK
IBM JDK
JRockit JDK

Issue

How do I enable Java large page support?

Resolution

First, large pages must be enabled in the operating system:

How do I enable large page support on Linux?
- For RHEL 6, is also recommended to disable Transparent Huge Pages Do I need to configure hugepages for JBoss on RHEL 6 even though transparent hugepages in RHEL 6 are fully automatic?
How do I enable large page support on Solaris?
How do I enable large page support on Windows?

OpenJDK / Sun JDK

Add the following JVM option:
```
-XX:+UseLargePages
```

Set the large page size. For example:

-XX:LargePageSizeInBytes=4m

Note: This option only has meaning on Solaris. On Linux, it is set to whatever page size is set in the kernel (Hugepagesize). On Windows it is fixed at 2 MB.

If you try to use this option on Linux, you will get the following warning:
OpenJDK 64-Bit Server VM warning: Setting LargePageSizeInBytes has no effect on this OS. Large page size is 2048K.

IBM JDK

Add the following JVM option:
```
-Xlp
```

##### JRockit JDK

Add the following JVM option:
```
-XXlargePages
```

SBR

Kernel

Product(s)

Red Hat Enterprise Linux

Components

kernel

Category

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Tags

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