On Wed, 23 Oct 2024 10:07:58 -0700 Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > To simplify later changes to page tag references, introduce new > pgtag_ref_handle type. This allows easy replacement of page_ext > as a storage of page allocation tags. > > ... > > static inline void pgalloc_tag_copy(struct folio *new, struct folio *old) > { > + union pgtag_ref_handle handle; > + union codetag_ref ref; > struct alloc_tag *tag; > - union codetag_ref *ref; > > tag = pgalloc_tag_get(&old->page); > if (!tag) > return; > > - ref = get_page_tag_ref(&new->page); > - if (!ref) > + if (!get_page_tag_ref(&new->page, &ref, &handle)) > return; > > /* Clear the old ref to the original allocation tag. */ > clear_page_tag_ref(&old->page); > /* Decrement the counters of the tag on get_new_folio. */ > - alloc_tag_sub(ref, folio_nr_pages(new)); > - > - __alloc_tag_ref_set(ref, tag); > - > - put_page_tag_ref(ref); > + alloc_tag_sub(&ref, folio_nr_pages(new)); mm-stable has folio_size(new) here, fixed up. I think we aleady discussed this, but there's a crazy amount of inlining here. pgalloc_tag_split() is huge, and has four callsites.