[$] Is it time to remove ZONE_DMA?

Post Syndicated from corbet original https://lwn.net/Articles/753273/rss

The DMA zone (ZONE_DMA) is a memory-management holdover from the
distant past. Once upon a time, many devices (those on the ISA bus in
particular) could only use 24 bits for DMA addresses, and were thus
limited to the bottom 16MB of memory. Such devices are hard to find on
contemporary computers. Luis Rodriguez scheduled the last
memory-management-track session of the 2018 Linux Storage, Filesystem, and
Memory-Management Summit to discuss whether the time has come to remove
ZONE_DMA altogether.