Re: [PATCH 2/2] mm/mglru: reset page lru tier bits when activating

[Andrew Morton]

On Mon, 14 Oct 2024 22:12:31 +0000 Wei Xu <weixugc@xxxxxxxxxx> wrote:

> folio_activate() calls lru_gen_add_folio() to move the folio to the
> youngest generation.  But unlike folio_update_gen()/folio_inc_gen(),
> lru_gen_add_folio() doesn't reset the folio lru tier bits
> (LRU_REFS_MASK | LRU_REFS_FLAGS).  Fix this inconsistency in
> lru_gen_add_folio() when activating a folio.

What are the runtime effects of this flaw?