Re: [PATCH RESEND 00/12] mm: add bitmap VMA flag helpers and convert all mmap_prepare to use them
Jason Gunthorpe <[email protected]>
| Newsgroups | gmane.comp.freedesktop.xorg.drivers.intel,gmane.linux.kernel,gmane.comp.video.dri.devel,gmane.linux.file-systems,gmane.linux.kernel.aio.general,gmane.comp.file-systems.ext4,gmane.linux.kernel.mm,gmane.linux.kernel.lsm |
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| Message-ID | <[email protected]> |
On Mon, Jan 19, 2026 at 09:19:02PM +0000, Lorenzo Stoakes wrote:
> We introduced the bitmap VMA type vma_flags_t in the aptly named commit
> 9ea35a25d51b ("mm: introduce VMA flags bitmap type") in order to permit
> future growth in VMA flags and to prevent the asinine requirement that VMA
> flags be available to 64-bit kernels only if they happened to use a bit
> number about 32-bits.
>
> This is a long-term project as there are very many users of VMA flags
> within the kernel that need to be updated in order to utilise this new
> type.
>
> In order to further this aim, this series adds a number of helper functions
> to enable ordinary interactions with VMA flags - that is testing, setting
> and clearing them.
>
> In order to make working with VMA bit numbers less cumbersome this series
> introduces the mk_vma_flags() helper macro which generates a vma_flags_t
> from a variadic parameter list, e.g.:
>
> vma_flags_t flags = mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT,
> VMA_EXEC_BIT);
I didn't try to check every conversion, but the whole approach looks
nice to me and I think this design is ergonomic!
Jason