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System Linux Memory

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System Linux memory is the portion of the host system memory reserved for use by the Linux kernel, Linux system processes, and user processes. The default value for the size of the System Linux memory when configured with the Azul Zulu Prime System Tools (ZST) system-config-zing-memory tool is 25% of the Host System memory.

To avoid page swapping of System Linux memory, ensure the amount of the operating system’s virtual memory plus the amount of System Zing memory (all if using the reserve-at-config policy or in use if using the reserve-at-config policy) is less than or equal to the size of the RAM. Should swapping occur during a Java heap garbage collection, potentially long delays can occur as pages are swapped.

Linux Kernel Memory

Linux kernel memory is memory required to run the Linux operating system. Linux kernel memory is reserved from System Linux memory.

malloc and mmapped Memory for Azul Zulu Prime JVM and Memory for other Linux Processes

Linux memory for processes is memory used by the Linux operating system to satisfy memory use requests from all the applications running on the system. This includes other Linux processes and the malloced and mmapped memory used by Azul Zulu Prime Builds of OpenJDK (Azul Zulu Prime JVM) running Java applications. The Linux memory used by each process is reserved from System Linux memory.

JNI Memory

Java applications use the Java Native Interface (JNI) to access native code. If the Java application uses JNI, any requests for non-Java heap memory made from the native code reserves memory from the System Linux memory.

There are two ways an application can allocate JNI memory. One is through JDK Java classes that call JNI functions. The other is through user-defined application classes that call user-defined JNI functions.

JVM non-Java Heap Memory

JVM non-Java Heap Memory is the System Linux memory used to support the ZVM instances running Java applications. JVM non-Java heap memory contains the ZVM executable code, thread stacks, and data structures for Azul Zulu Prime JVM’s Generational Pauseless Garbage Collector. The amount of memory being consumed at any moment varies depending upon the Azul Zulu Prime JVM instance and Java application’s requirements.

Other Linux Processes Using Memory

If any other processes are running on the system, such as MySQL or Apache, these processes use System Linux memory. These other Linux processes running on the system compete for memory and reduce the amount of Linux memory available to the Azul Zulu Prime JVMs running Java applications.

Other Linux Processes Using Memory

If any other processes are running on the system, such as MySQL or Apache, these processes use System Linux memory. These other Linux processes running on the system compete for memory and reduce the amount of Linux memory available to the Azul Zulu Prime JVMs running Java applications.