Re: [PATCH 3/3] io_uring: follow **iovec idiom in io_import_iovec

Pavel Begunkov
2020-07-13T21:14:29Z

On 14/07/2020 00:09, Jens Axboe wrote:
> On 7/13/20 1:59 PM, Pavel Begunkov wrote:
>> @@ -3040,8 +3040,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
>> }
>> }
>> out_free:
>> - if (!(req->flags & REQ_F_NEED_CLEANUP))
>> - kfree(iovec);
>> + kfree(iovec);
>> return ret;
>> }
>
> Faster to do:
>
> if (iovec)
> kfree(iovec)
>
> to avoid a stupid call. Kind of crazy, but I just verified with this one
> as well that it's worth about 1.3% CPU in my stress test.

That looks crazy indeed

> Apart from that, looks good, I just folded in that change.

Great, thanks

--
Pavel Begunkov