Request:

Can we have persistent memory support documented in 10.5 release notes? And somewhere in the documentation. I suspect it should be a separate article, mostly to explain pmem configuration.

To make use of persistent memory the server has to be compiled with cmake -DWITH_PMEM=ON, it requires libpmem library installed.
Only InnoDB redo log supports pmem. It uses different IO method (mmap-ed) on pmem, which results in better performance. One should point InnoDB redo log to pmem with --innodb-log-group-home-dir=/path/to/pmem/filesystem.

pmem support was released along with 10.5.2

https://jira.mariadb.org/browse/MDEV-17084

daaa881cfe3466c298fa44812b8477a23d25b756 - libpmem cmake macros
3daef523af25e4f1e4e75d2c26a9b25475f0c679 - MDEV-17084 Optimize append only files for NVDIMM