On Wed, Oct 30, 2024 at 10:35:47AM GMT, Joanne Koong wrote: > On Wed, Oct 30, 2024 at 10:27 AM Bernd Schubert > <bernd.schubert@xxxxxxxxxxx> wrote: > > > > > > Hmm, if tmp pages can be compacted, isn't that a problem for splice? > > I.e. I don't understand what the difference between tmp page and > > write-back page for migration. > > > > That's a great question! I have no idea how compaction works for pages > being used in splice. Shakeel, do you know the answer to this? > Sorry for the late response. I still have to go through other unanswered questions but let me answer this one quickly. From the way the tmp pages are allocated, it does not seem like they are movable and thus are not target for migration/compaction. The page with the writeback bit set is actually just a user memory page cache which is moveable but due to, at the moment, under writeback it temporarily becomes unmovable to not cause corruption. Shakeel