On Wed, Mar 12, 2025 at 08:20:36AM -0700, Suren Baghdasaryan wrote: > > Direct I/O pages are not unmovable. They are temporarily pinned for > > the duration of the direct I/O. > > Yes but even temporarily pinned pages can cause CMA allocation > failure. My point is that if we know beforehand that the pages will be > pinned we could avoid using CMA and these failures would go away. Direct I/O (and other users of pin_user_pages) are designed to work on all anonymous and file backed pages, which is kinda the point. If you CMA user can't wait for the time of an I/O something is wrong with that caller and it really should not use CMA.
