Re: [PATCHSET] Add support for simplified async direct-io

[Jens Axboe <axboe@kernel.dk>]

On 11/17/2016 06:25 AM, Jens Axboe wrote:
> On 11/17/2016 05:50 AM, Christoph Hellwig wrote:
>> On Wed, Nov 16, 2016 at 09:43:57PM -0700, Jens Axboe wrote:
>>> OK, I'm getting reasonably happy with it now:
>>>
>>> http://git.kernel.dk/cgit/linux-block/log/?h=for-4.10/hch-dio
>>>
>>> Sharing the FUA setting to avoid the manual flush between the two, and
>>> removing the remnants of SYNC support from __blkdev_direct_IO().
>>>
>>> I'll fire off some overnight testing now and leave it for the day.
>>
>> This looks reasonable, a couple questions and comments:
>>
>>  - why the 8 * BIO_MAX_PAGES in the call to iov_iter_npages,
>>    that probably needs a comment
>
> Looks like I forgot to push out the latest changes, that is gone. We're
> just using + 1 now to see if we should use the multibio function or not.

Just to clarify, the correct tip is:

commit 18eb8e94477813c190a2dfcd790c6707ab168377
Author: Jens Axboe <axboe@fb.com>
Date:   Wed Nov 16 23:20:41 2016 -0700

     block: save 8 bytes of space in struct blkdev_dio

That's what I ran in my overnight testing, and it looks fine from my
end.

-- 
Jens Axboe