On Fri, Nov 08, 2024 at 10:43:31AM -0700, Jens Axboe wrote:
> +++ b/mm/swap.c
> @@ -472,6 +472,8 @@ static void folio_inc_refs(struct folio *folio)
> */
> void folio_mark_accessed(struct folio *folio)
> {
> + if (folio_test_uncached(folio))
> + return;
> if (lru_gen_enabled()) {
This feels like it might be a problem. If, eg, process A is doing
uncached IO and process B comes along and, say, mmap()s it, I think
we'll need to clear the uncached flag in order to have things work
correctly. It's a performance problem, not a correctness problem.
