On Mon, Nov 14, 2016 at 10:28:37AM -0700, Jens Axboe wrote:

This is on top of for-4.10/dio, which has Christophs simplified sync
O_DIRECT support and the IO poll bits.

The restriction on 4 inline vecs is removed on the sync support, we
just allocate the bio_vec array if we have to. I realize this negates
parts of the win of the patch for sync, but it's still a lot leaner
than the old code. And it means we use the same path for any type
of sync O_DIRECT, instead of potentially bouncing between the two.

Second patch is adding async support for the code base. Lightly
tested. Performance results, from fio:

І'd much rather add a separate path pased on the same scheme.  And
because I prefer that so much I actually did it a while ago, although
it will need some minor updates for the current tree:

	http://git.infradead.org/users/hch/block.git/shortlog/refs/heads/new-dio

I'll see if I can get it quickly updated..