Understanding the Virtual Memory Map. The virtual memory consumed by a process is the total of everything that's in the process memory map. This includes data (eg, the Java heap), but also all of the shared libraries and memory-mapped files used by the program.

In terms of Java heap size, in Linux, you can use. ps aux | grep java or. ps -ef | grep java and look for -Xms, -Xmx to find out the initial and maximum heap size specified. However, if -Xms or -Xmx is absent for the Java process you are interested in, it means your Java process is using the default heap sizes.

Dec 17, 2024 · The jmap tool is an integral part of Java’s suite of diagnostic tools, used to analyze and monitor various aspects of memory in Java applications. Specifically, it provides insights into memory footprint, heap usage, shared object mappings, and more.

Dec 10, 2021 · mmap is a memory mapping method that maps a file to a process address space, mapping a file’s disk address to a process virtual address.

Apr 9, 2013 · If you need to read from the block device as a memory mapped file directly, you may need to write some C/C++ code to map the file and handle reading/writing to it and use a Java/JNI bridge class to bridge calls to your C/C++ code.

“jmap” is a command-line tool provided as part of the Java Development Kit (JDK), used for analyzing and troubleshooting Java memory usage in running Java applications. It provides insights into the memory utilization of a Java process, allowing developers and system administrators to diagnose memory-related issues and optimize memory usage.

Sep 6, 2018 · On current x86_64 CPU’s the memory will be laid out according to "virtual memory map with 4 level page tables" which is specified in the Linux kernel documentation under Documentation/x86/x86_64/mm.txt:

Feb 27, 2024 · The Memory-mapped files in Java offer a powerful mechanism to map a region of a file directly into the memory providing efficient access to file data. This method enhances the performance when dealing with large files or when frequent access to the file data is required.

Apr 6, 2022 · Memory-mapped files are casual special files in Java that help to access content directly from memory. Java Programming supports memory-mapped files with java.nio package. Memory-mapped I/O uses the filesystem to establish a virtual memory mapping from the user directly to the filesystem pages.

Dec 8, 2022 · You can also use it to analyze a memory value that always increases and never decreases or to locate the culprit of a memory leak. This example is a brief overview of what's possible to learn about a single process.