Messages in this thread | | | Date | Sun, 15 Oct 2017 08:58:56 +0200 | From | Pavel Machek <> | Subject | Re: [RFC PATCH 3/3] mm/map_contig: Add mmap(MAP_CONTIG) support |
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Hi!
> Yes you wrote that already and my counter argument was that this generic > posix interface shouldn't bypass virtual memory abstraction. > > > > > The contiguous allocations are particularly useful for the RDMA API which > > > > allows registering user space memory with devices. > > > > > > then make those devices expose an implementation of an mmap which does > > > that. You would get both a proper access control (via fd), accounting > > > and others. > > > > There are numerous RDMA devices that would all need the mmap > > implementation. And this covers only the needs of one subsystem. There are > > other use cases. > > That doesn't prevent providing a library function which could be reused > by all those drivers. Nothing really too much different from > remap_pfn_range.
So you'd suggest using ioctl() for allocating memory?
That sounds quite ugly to me... mmap(MAP_CONTIG) is not nice, either, but better than each driver inventing custom interface... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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