On Mon, Nov 11, 2024 at 04:37:30PM -0700, Jens Axboe wrote: > Add a page flag that file IO can use to indicate that the IO being done > is uncached, as in it should not persist in the page cache after the IO > has been completed. I have not found a way to avoid using a new bit. I am unsure if we have enough bits on 32-bit systems with all possible features enabled. In the worst-case scenario, we may need to make the feature 64-bit only. I believe it should be acceptable as long as userspace is prepared for the possibility that RWF_UNCACHED may fail. It is not going to be supported by all filesystems anyway. -- Kiryl Shutsemau / Kirill A. Shutemov
