Filesystem and Memory Reclaim

When we want to allocate memory, but it’s all in use, it’s time to ask various users to give some of the memory back. Filesystems are some of the more complicated users of memory, and asking them to free memory is correspondingly complicated.

Much previous work in this area has focused on avoiding deadlocks between filesystems allocating memory and then being asked to reclaim memory. A set of recent bug reports alerted us to a new way for filesystems to allocate memory in order to free memory.

This talk will cover the existing ways we avoid deadlocks, and how we might solve the exciting new problem.

Matthew WILCOX

Matthew WILCOX

Oracle

Matthew has been a Linux kernel hacker for 25 years. He has worked on many parts of the kernel including the Arm, PA-RISC and ia64 architectures, TASK_KILLABLE, PCI, SCSI, NVMe, USB, filesystems, file locking, DAX and the XArray. He works for Oracle on a variety of projects including memory management and filesystems. He is currently the page cache maintainer.