For people who don’t know what MGLRU (Multi-Generation Least Recently Used) page cache algorithm is:

https://www.phoronix.com/scan.php?page=news_item&px=MGLRU-v1...

> There are wins reported for Cassandra, Hadooop, MySQL/MariaDB, Memcached, MongoDB, PostgreSQL, Redis, and improving the behavior in general for systems with limited RAM capacities or a lot of memory intense activities.

> MGLRU is already shipping with Google Android devices and also patched into Google's Chrome OS kernel.

That page didn't really explain MGLRU, at least to me. These pages however helped a lot:

https://lwn.net/Articles/856931/

https://lwn.net/Articles/894859/

An aspect I found interesting was that, in addition to the LRU aspect, it includes a PID controller to try to learn or compensate for its mistakes.

It is very exciting. Sounds like other filesystems under Linux now get zfs Adaptive Replacement Cache for free.

Will they bump the version number to 6?

Why would they? Linus changes version numbers on a whim, he stated that multiple times. Partly to make it obvious that all kernel releases are equal, partly for no reason at all.