Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap flags

Kirill A. Shutemov
2017-08-25T16:16:13Z

On Fri, Aug 25, 2017 at 09:02:36AM -0700, Christoph Hellwig wrote:
> On Fri, Aug 25, 2017 at 06:58:03PM +0300, Kirill A. Shutemov wrote:
> > Not all archs are ready for this:
> >
> > arch/parisc/include/uapi/asm/mman.h:#define MAP_TYPE 0x03 /* Mask for type of mapping */
> > arch/parisc/include/uapi/asm/mman.h:#define MAP_FIXED 0x04 /* Interpret addr exactly */
>
> I'd be happy to say that we should not care about parisc for
> persistent memory. We'll just have to find a way to exclude
> parisc without making life too ugly.

I don't think creapling mmap() interface for one arch is the right way to
go. I think the interface should be universal.

I may imagine MAP_DIRECT can be useful not only for persistent memory.
For tmpfs instead of mlock()?

--
Kirill A. Shutemov