| Date | Fri, 15 Sep 2023 20:00:06 +0100 | From | Matthew Wilcox <> | Subject | Re: [RFC 03/23] filemap: add folio with at least mapping_min_order in __filemap_get_folio |
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On Fri, Sep 15, 2023 at 08:38:28PM +0200, Pankaj Raghav wrote: > +++ b/mm/filemap.c > @@ -1862,6 +1862,10 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, > fgf_t fgp_flags, gfp_t gfp) > { > struct folio *folio; > + int min_order = mapping_min_folio_order(mapping); > + int nr_of_pages = (1U << min_order); > + > + index = round_down(index, nr_of_pages); > > repeat: > folio = filemap_get_entry(mapping, index); > @@ -1929,8 +1933,14 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index, > err = -ENOMEM; > if (order == 1) > order = 0; > + if (order < min_order) > + order = min_order;
... oh, you do something similar here to what I recommend in my previous response. I don't understand why you need the previous patch.
> + if (min_order) > + VM_BUG_ON(index & ((1UL << order) - 1));
You don't need the 'if' here; index & ((1 << 0) - 1) becomes false.
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