Matthew Wilcox <willy@xxxxxxxxxxxxx> writes: > On Tue, Jul 25, 2023 at 11:53:26PM -0600, Yu Zhao wrote: >> > +void folio_remove_rmap_range(struct folio *folio, struct page *page, >> > + int nr, struct vm_area_struct *vma); >> >> I prefer folio_remove_rmap_range(page, nr, vma). Passing both the >> folio and the starting page seems redundant to me. >> >> Matthew, is there a convention (function names, parameters, etc.) for >> operations on a range of pages within a folio? > > We've been establishing that convention recently, yes. It seems > pointless to re-derive the folio from the page when the caller already > has the folio. I also like Ryan's point that it reinforces that all > pages must be from the same folio. > >> And regarding the refactor, what I have in mind is that >> folio_remove_rmap_range() is the core API and page_remove_rmap() is >> just a wrapper around it, i.e., folio_remove_rmap_range(page, 1, vma). >> >> Let me post a diff later and see if it makes sense to you. > > I think that can make sense. Because we limit to a single page table, > specifying 'nr = 1 << PMD_ORDER' is the same as 'compound = true'. > Just make it folio, page, nr, vma. I'd actually prefer it as (vma, > folio, page, nr), but that isn't the convention we've had in rmap up > until now. IIUC, even if 'nr = 1 << PMD_ORDER', we may remove one PMD 'compound' mapping, or 'nr' PTE mapping. So, we will still need 'compound' (or some better name) as parameter. -- Best Regards, Huang, Ying
