search for: make_device_exclusive

...device-exclusive, it doesn't really work with THP >> and is only limited to anonymous memory. I have patches to at least make it >> work reliably with THP. > > I should have crawled through the implementation first before replying. > Since it only looks at folio_mapcount() make_device_exclusive() should at > least in theory work reliably on anon memory, and not be impacted by > elevated refcounts due to migration/ksm/thp/whatever. Yes, there is -- in theory -- nothing blocking the conversion except the folio lock. That's different than page migration. [...] > >> Th...

...access it, as soon as the "device exclusive non-swap entry" is in place, only the device can access it. Conversion back and forth is triggered by CPU / device faults. I have fixes/reworks/simplifications for most things, but as there is only a "real" single user in-tree of make_device_exclusive(): drivers/gpu/drm/nouveau/nouveau_svm.c to "support SVM atomics in Nouveau [1]" naturally I am wondering: is this still a thing on actual hardware, or is it already stale on recent hardware and not really required anymore? [1] https://lore.kernel.org/linux-kernel//6621654.gmDyfcmp...