Groups > linux.kernel > #1720244

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

From	Helge Deller <deller@gmx.de>
Newsgroups	linux.kernel
Subject	Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap flags
Date	2017-08-25 18:30 +0200
Message-ID	<uipEB-6ki-1@gated-at.bofh.it> (permalink)
References	(3 earlier) <ui4gP-17m-33@gated-at.bofh.it> <uimx3-4tc-7@gated-at.bofh.it> <uipbz-5V8-7@gated-at.bofh.it> <uiplh-6dJ-41@gated-at.bofh.it> <uipuW-6gP-27@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 25.08.2017 18:16, Kirill A. Shutemov wrote:
> 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()?

On parisc we have
#define MAP_SHARED      0x01            /* Share changes */
#define MAP_PRIVATE     0x02            /* Changes are private */
#define MAP_TYPE        0x03            /* Mask for type of mapping */
#define MAP_FIXED       0x04            /* Interpret addr exactly */
#define MAP_ANONYMOUS   0x10            /* don't use a file */

So, if you need a MAP_DIRECT, wouldn't e.g.
#define MAP_DIRECT      0x08
be possible (for parisc, and others 0x04).
And if MAP_TYPE needs to include this flag on parisc:
#define MAP_TYPE        (0x03 | 0x08)  /* Mask for type of mapping */

Helge

Thread

[PATCH v6 0/5] MAP_DIRECT and block-map-atomic files Dan Williams <dan.j.williams@intel.com> - 2017-08-24 02:00 +0200
  [PATCH v6 4/5] fs,  xfs: introduce MAP_DIRECT for creating block-map-atomic file ranges Dan Williams <dan.j.williams@intel.com> - 2017-08-24 02:00 +0200
    Re: [PATCH v6 4/5] fs, xfs: introduce MAP_DIRECT for creating         block-map-atomic file ranges Christoph Hellwig <hch@lst.de> - 2017-08-24 18:20 +0200
      Re: [PATCH v6 4/5] fs, xfs: introduce MAP_DIRECT for creating         block-map-atomic file ranges Christoph Hellwig <hch@lst.de> - 2017-08-24 18:40 +0200
        Re: [PATCH v6 4/5] fs, xfs: introduce MAP_DIRECT for creating  block-map-atomic file ranges Dan Williams <dan.j.williams@intel.com> - 2017-08-24 22:30 +0200
      Re: [PATCH v6 4/5] fs, xfs: introduce MAP_DIRECT for creating  block-map-atomic file ranges Dan Williams <dan.j.williams@intel.com> - 2017-08-24 18:40 +0200
  [PATCH v6 5/5] fs, fcntl: add F_MAP_DIRECT Dan Williams <dan.j.williams@intel.com> - 2017-08-24 02:00 +0200
  [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap  flags Dan Williams <dan.j.williams@intel.com> - 2017-08-24 02:00 +0200
    Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap  flags Jan Kara <jack@suse.cz> - 2017-08-24 15:10 +0200
    Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap  flags Christoph Hellwig <hch@infradead.org> - 2017-08-24 19:00 +0200
      Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap flags Dan Williams <dan.j.williams@intel.com> - 2017-08-24 19:40 +0200
        Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap  flags Christoph Hellwig <hch@infradead.org> - 2017-08-25 15:10 +0200
          Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap  flags "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-08-25 18:00 +0200
            Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap  flags Christoph Hellwig <hch@infradead.org> - 2017-08-25 18:10 +0200
              Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap  flags "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-08-25 18:20 +0200
                Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap  flags Helge Deller <deller@gmx.de> - 2017-08-25 18:30 +0200
                Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap  flags "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2017-08-25 19:00 +0200
                Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap flags Dan Williams <dan.j.williams@intel.com> - 2017-08-25 22:30 +0200
                Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap  flags Helge Deller <deller@gmx.de> - 2017-08-26 09:50 +0200
                Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap flags Dan Williams <dan.j.williams@intel.com> - 2017-08-26 17:20 +0200
                Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap  flags Helge Deller <deller@gmx.de> - 2017-08-26 22:00 +0200
                Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap flags Dan Williams <dan.j.williams@intel.com> - 2017-08-27 00:50 +0200
                Re: [PATCH v6 3/5] mm: introduce mmap3 for safely defining new mmap  flags "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-08-27 02:00 +0200
  [PATCH v6 2/5] fs, xfs: introduce S_IOMAP_SEALED Dan Williams <dan.j.williams@intel.com> - 2017-08-24 02:00 +0200
    Re: [PATCH v6 2/5] fs, xfs: introduce S_IOMAP_SEALED Christoph Hellwig <hch@lst.de> - 2017-08-24 18:20 +0200
      Re: [PATCH v6 2/5] fs, xfs: introduce S_IOMAP_SEALED Dan Williams <dan.j.williams@intel.com> - 2017-08-25 08:10 +0200
        Re: [PATCH v6 2/5] fs, xfs: introduce S_IOMAP_SEALED Dan Williams <dan.j.williams@intel.com> - 2017-08-25 21:50 +0200
  Re: [PATCH v6 0/5] MAP_DIRECT and block-map-atomic files Christoph Hellwig <hch@lst.de> - 2017-08-24 18:10 +0200
    Re: [PATCH v6 0/5] MAP_DIRECT and block-map-atomic files Dan Williams <dan.j.williams@intel.com> - 2017-08-24 18:30 +0200
  Re: [PATCH v6 1/5] vfs: add flags parameter to ->mmap() in 'struct  file_operations' Christoph Hellwig <hch@infradead.org> - 2017-08-24 19:00 +0200
    Re: [PATCH v6 1/5] vfs: add flags parameter to ->mmap() in 'struct file_operations' Dan Williams <dan.j.williams@intel.com> - 2017-08-24 19:50 +0200

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