On 7/14/25 9:10 PM, Qi Han wrote: > Jens has already completed the development of uncached buffered I/O > in git [1], and in f2fs, the feature can be enabled simply by setting > the FOP_DONTCACHE flag in f2fs_file_operations.
You need to ensure that for any DONTCACHE IO that the completion is routed via non-irq context, if applicable. I didn't verify that this is the case for f2fs. Generally you can deduce this as well through testing, I'd say the following cases would be interesting to test: 1) Normal DONTCACHE buffered read 2) Overwrite DONTCACHE buffered write 3) Append DONTCACHE buffered write Test those with DEBUG_ATOMIC_SLEEP set in your config, and it that doesn't complain, that's a great start. For the above test cases as well, verify that page cache doesn't grow as IO is performed. A bit is fine for things like meta data, but generally you want to see it remain basically flat in terms of page cache usage. Maybe this is all fine, like I said I didn't verify. Just mentioning it for completeness sake. -- Jens Axboe _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
