[$] 5.1 Merge window part 1

Post Syndicated from corbet original https://lwn.net/Articles/782511/rss

As of this writing, 6,135 non-merge changesets have been pulled into the
mainline repository for the 5.1 release. That is approximately halfway
through the expected merge-window volume, which is a good
time for a summary. A number of important new features have been merged
for this release; read on for the details.