Messages in this thread | | | Date | Mon, 14 Aug 2023 16:01:08 -0700 | Subject | Re: [PATCH RFC v2 0/3] mm: Properly document tail pages for a folio | From | Randy Dunlap <> |
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On 8/14/23 12:58, Matthew Wilcox wrote: > On Mon, Aug 14, 2023 at 02:44:08PM -0400, Peter Xu wrote: > > Look, this is all still too complicated. And you're trying to make > something better that I'm trying to make disappear. I'd really rather > you spent your time worrying about making userfaultfd use folios > than faffing with this. > > How about this? > > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index 5e74ce4a28cd..873285bb5d45 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -334,11 +334,14 @@ struct folio { > /* public: */ > unsigned char _folio_dtor; > unsigned char _folio_order; > + /* two bytes available here */ > atomic_t _entire_mapcount; > atomic_t _nr_pages_mapped; > atomic_t _pincount; > + /* no more space on 32-bt */
32-bit
> #ifdef CONFIG_64BIT > unsigned int _folio_nr_pages; > + /* twelve bytes available on 64-bit */ > #endif > /* private: the union with struct page is transitional */ > }; > @@ -360,6 +363,7 @@ struct folio { > unsigned long _head_2a; > /* public: */ > struct list_head _deferred_list; > + /* three more words available here */ > /* private: the union with struct page is transitional */ > }; > struct page __page_2;
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