What are the main purposes and functions of the Linux Out-Of-Memory (OOM) management system?

OOM (Out Of Memory) is a memory management system in Linux that triggers when the system runs out of RAM and swap to satisfy application requests.

Main purposes and functions of OOM:

• Detecting memory shortage: The Linux kernel monitors memory usage and activates OOM when there is a critical shortage.
• Selecting a process to terminate: The OOM killer chooses a process to kill in order to free up memory. The selection is based on various criteria, including memory consumption, process priority, and other parameters.
• Preventing system crash: By killing one or more processes, OOM prevents a complete system crash due to memory exhaustion.

Thus, OOM is a system protection mechanism against total hang or crash when memory is exhausted, automatically terminating the most "expensive" processes to restore operability.