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Shutemov" References: <20230814184411.330496-1-peterx@redhat.com> From: Randy Dunlap In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 639F740026 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: 4eantmgowgs8xygiahr95mrxxecp4muz X-HE-Tag: 1692054077-605550 X-HE-Meta: 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 d2ciDHD8 M6xVCOA2YJp/wt6VZ8agSfU9pws/T+41dPV+OOUcOVhPb1BKFl/P7ZjVqUZSTopRS86akAyIYOuZjJg1G+gk/jguinXZSmq4rXEkG3ollZnQcry8RDV1ElflaFKGVkEYDC1iDL0I64oLjzdURukjFHrVP6e188jHbHB2gEsMAt9DkYquQLVcwaxmwRiCqUzBECLGideSHEtEeuLw= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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;