Re: [PTACH] fs: get rid of the res2 iocb->ki_complete argument

[Jens Axboe <axboe@kernel.dk>]

On 10/25/21 10:16 AM, Darrick J. Wong wrote:
> On Mon, Oct 25, 2021 at 09:33:02AM -0600, Jens Axboe wrote:
>> The second argument was only used by the USB gadget code, yet everyone
>> pays the overhead of passing a zero to be passed into aio, where it
>> ends up being part of the aio res2 value.
>>
>> Now that everybody is passing in zero, kill off the extra argument.
>>
>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> 
> The fs/ parts look reasonable to me.
> Reviewed-by: Darrick J. Wong <djwong@kernel.org>

Thanks!

> So, uh, do you get even more iops by avoiding the extra register? :)

Heh, well if you're register starved, it'll likely make a bigger
difference, but even on my CPU it is actually noticeable. Obviously not
a 10% gain, and the change is more about cleaning up the API a bit.

-- 
Jens Axboe