Messages in this thread | | | Subject | Re: [PATCH 0/5] bio: Direct IO: convert to pin_user_pages_fast() | From | John Hubbard <> | Date | Mon, 24 Aug 2020 19:07:02 -0700 |
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On 8/24/20 6:54 PM, Al Viro wrote: > On Fri, Aug 21, 2020 at 09:20:54PM -0700, John Hubbard wrote: > >> Direct IO behavior: >> >> ITER_IOVEC: >> pin_user_pages_fast(); >> break; >> >> ITER_KVEC: // already elevated page refcount, leave alone >> ITER_BVEC: // already elevated page refcount, leave alone >> ITER_PIPE: // just, no :) > > Why? What's wrong with splice to O_DIRECT file? >
Oh! I'll take a look. Is this the fs/splice.c stuff? I ruled this out early mainly based on Christoph's comment in [1] ("ITER_PIPE is rejected іn the direct I/O path"), but if it's supportable then I'll hook it up.
(As you can see, I'm still very much coming up to speed on the various things that invoke iov_iter_get_pages*().)
[1] https://lore.kernel.org/kvm/20190724061750.GA19397@infradead.org/
thanks, -- John Hubbard NVIDIA
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