On Thu, Aug 01, 2019 at 07:16:19PM -0700, john.hubbard@xxxxxxxxx wrote: > This is part a tree-wide conversion, as described in commit fc1d8e7cca2d > ("mm: introduce put_user_page*(), placeholder versions"). That commit > has an extensive description of the problem and the planned steps to > solve it, but the highlites are: That is one horridly mangled Changelog there :-/ It looks like it's partially duplicated. Anyway; no objections to any of that, but I just wanted to mention that there are other problems with long term pinning that haven't been mentioned, notably they inhibit compaction. A long time ago I proposed an interface to mark pages as pinned, such that we could run compaction before we actually did the pinning.