Sony engineer Peter Enderborg recently submitted an email to the Linux kernel LKML, proposing a new Watchdog software that can optimize the solution of a device running out of memory.
Watchdog software is a monitoring program that periodically checks the health of a device and, when an unrecoverable error is encountered, issues a restart signal to resolve the problem. It has the highest priority in the software.
Sony will bring an out-of-memory solution to Linux
The email states that instead of performing a hard restart, the new watchdog will take a "predefined action" to try to kill non-critical processes, using "oom_score_adj" monitoring. The watchdog will kill the process with the highest "oom_score_adj".
The "oom_score" is the score that the Linux kernel assigns to each running process. A higher number indicates a higher memory usage for the process, while "oom_score_adj" is a number between -1000 and 1000, where a higher number means the process is less important.
When "oom_score" is combined with "oom_score_adj", it is possible to find processes that have a large memory footprint and are less important to free memory.