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Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: [PATCH v8 10/10] mm: Renumber FOLL_PIN and FOLL_GET down Content-Language: en-US To: David Howells , Al Viro , Christoph Hellwig CC: Matthew Wilcox , Jens Axboe , "Jan Kara" , Jeff Layton , Logan Gunthorpe , , , , "Christoph Hellwig" , References: <20230123173007.325544-1-dhowells@redhat.com> <20230123173007.325544-11-dhowells@redhat.com> From: John Hubbard In-Reply-To: <20230123173007.325544-11-dhowells@redhat.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.126.230.37] X-ClientProxiedBy: rnnvmail203.nvidia.com (10.129.68.9) To rnnvmail201.nvidia.com (10.129.68.8) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CO1NAM11FT065:EE_|MN2PR12MB4189:EE_ X-MS-Office365-Filtering-Correlation-Id: e00a5585-07fb-4ab7-3b2e-08dafdb85121 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; 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Should we also get these sorted into internal-to-mm and public sets? Because Jason (+Cc) again was about to split them apart into mm/internal.h [1] and that might make that a little cleaner. Also, I don't think that there is any large readability difference either way between 0x and <<1, so whatever you and Christophe settle on there seems fine. So either way with those points, Reviewed-by: John Hubbard thanks, -- John Hubbard NVIDIA > > Signed-off-by: David Howells > cc: Al Viro > cc: Christoph Hellwig > cc: Matthew Wilcox > cc: linux-fsdevel@vger.kernel.org > cc: linux-mm@kvack.org > --- > > Notes: > ver #8) > - Put FOLL_PIN at bit 0 and FOLL_GET at bit 1 to match BIO_PAGE_*. > - Renumber the remaining flags down to fill in the gap. > > include/linux/mm.h | 32 +++++++++++++++++--------------- > 1 file changed, 17 insertions(+), 15 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 3de9d88f8524..c95bc4f77e8f 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -3074,26 +3074,28 @@ static inline vm_fault_t vmf_error(int err) > struct page *follow_page(struct vm_area_struct *vma, unsigned long address, > unsigned int foll_flags); > > -#define FOLL_WRITE 0x01 /* check pte is writable */ > -#define FOLL_TOUCH 0x02 /* mark page accessed */ > -#define FOLL_GET 0x04 /* do get_page on page */ > -#define FOLL_DUMP 0x08 /* give error on hole if it would be zero */ > -#define FOLL_FORCE 0x10 /* get_user_pages read/write w/o permission */ > -#define FOLL_NOWAIT 0x20 /* if a disk transfer is needed, start the IO > +#define FOLL_PIN 0x01 /* pages must be released via unpin_user_page */ > +#define FOLL_GET 0x02 /* do get_page on page (equivalent to BIO_FOLL_GET) */ > +#define FOLL_WRITE 0x04 /* check pte is writable */ > +#define FOLL_TOUCH 0x08 /* mark page accessed */ > +#define FOLL_DUMP 0x10 /* give error on hole if it would be zero */ > +#define FOLL_FORCE 0x20 /* get_user_pages read/write w/o permission */ > +#define FOLL_NOWAIT 0x40 /* if a disk transfer is needed, start the IO > * and return without waiting upon it */ > #define FOLL_NOFAULT 0x80 /* do not fault in pages */ > #define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */ > -#define FOLL_TRIED 0x800 /* a retry, previous pass started an IO */ > -#define FOLL_REMOTE 0x2000 /* we are working on non-current tsk/mm */ > -#define FOLL_ANON 0x8000 /* don't do file mappings */ > -#define FOLL_LONGTERM 0x10000 /* mapping lifetime is indefinite: see below */ > -#define FOLL_SPLIT_PMD 0x20000 /* split huge pmd before returning */ > -#define FOLL_PIN 0x40000 /* pages must be released via unpin_user_page */ > -#define FOLL_FAST_ONLY 0x80000 /* gup_fast: prevent fall-back to slow gup */ > -#define FOLL_PCI_P2PDMA 0x100000 /* allow returning PCI P2PDMA pages */ > -#define FOLL_INTERRUPTIBLE 0x200000 /* allow interrupts from generic signals */ > +#define FOLL_TRIED 0x200 /* a retry, previous pass started an IO */ > +#define FOLL_REMOTE 0x400 /* we are working on non-current tsk/mm */ > +#define FOLL_ANON 0x800 /* don't do file mappings */ > +#define FOLL_LONGTERM 0x1000 /* mapping lifetime is indefinite: see below */ > +#define FOLL_SPLIT_PMD 0x2000 /* split huge pmd before returning */ > +#define FOLL_FAST_ONLY 0x4000 /* gup_fast: prevent fall-back to slow gup */ > +#define FOLL_PCI_P2PDMA 0x8000 /* allow returning PCI P2PDMA pages */ > +#define FOLL_INTERRUPTIBLE 0x10000 /* allow interrupts from generic signals */ > > /* > + * Note that FOLL_PIN is sorted to bit 0 to be coincident with BIO_PAGE_PINNED. > + * > * FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each > * other. Here is what they mean, and how to use them: > * > >