From: Pavel Begunkov <asml.silence@gmail.com>
To: Noah Goldstein <goldstein.w.n@gmail.com>
Cc: "open list:IO_URING" <io-uring@vger.kernel.org>,
Jens Axboe <axboe@kernel.dk>
Subject: Re: [PATCH 8/8] io_uring: rearrange io_read()/write()
Date: Sun, 17 Oct 2021 00:25:22 +0100 [thread overview]
Message-ID: <869d5110-973b-6c70-604d-48d6108c0379@gmail.com> (raw)
In-Reply-To: <CAFUsyfKyRnXhcxOVfSAxeyKsQqGXJ7PdDYw3TXC3H+q_yp5LMA@mail.gmail.com>
On 10/16/21 23:52, Noah Goldstein wrote:
> On Thu, Oct 14, 2021 at 10:13 AM Pavel Begunkov <asml.silence@gmail.com> wrote:
>> - /* If the file doesn't support async, just async punt */
>> - if (force_nonblock && !io_file_supports_nowait(req, WRITE))
>> - goto copy_iov;
>> + /* file path doesn't support NOWAIT for non-direct_IO */
>> + if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
>
> You can drop this 'force_nonblock' no?
Indeed
>
>> + (req->flags & REQ_F_ISREG))
>> + goto copy_iov;
>>
>> - /* file path doesn't support NOWAIT for non-direct_IO */
>> - if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
>> - (req->flags & REQ_F_ISREG))
>> - goto copy_iov;
>> + kiocb->ki_flags |= IOCB_NOWAIT;
>> + } else {
>> + /* Ensure we clear previously set non-block flag */
>> + kiocb->ki_flags &= ~IOCB_NOWAIT;
>> + }
>>
>> ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), req->result);
>> if (unlikely(ret))
>
> ...
>
> What swapping order of conditions below:
> if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN)
>
> The ret2 check will almost certainly be faster than 2x deref.
Makes sense. Want to send a patch?
--
Pavel Begunkov
next prev parent reply other threads:[~2021-10-16 23:26 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-14 15:10 [PATCH for-next 0/8] read/write cleanup Pavel Begunkov
2021-10-14 15:10 ` [PATCH 1/8] io_uring: consistent typing for issue_flags Pavel Begunkov
2021-10-14 15:10 ` [PATCH 2/8] io_uring: prioritise read success path over fails Pavel Begunkov
2021-10-14 15:10 ` [PATCH 3/8] io_uring: optimise rw comletion handlers Pavel Begunkov
2021-10-14 15:10 ` [PATCH 4/8] io_uring: encapsulate rw state Pavel Begunkov
2021-10-18 6:06 ` Hao Xu
2021-10-14 15:10 ` [PATCH 5/8] io_uring: optimise read/write iov state storing Pavel Begunkov
2021-10-14 15:10 ` [PATCH 6/8] io_uring: optimise io_import_iovec nonblock passing Pavel Begunkov
2021-10-14 15:10 ` [PATCH 7/8] io_uring: clean up io_import_iovec Pavel Begunkov
2021-10-14 15:10 ` [PATCH 8/8] io_uring: rearrange io_read()/write() Pavel Begunkov
2021-10-16 22:52 ` Noah Goldstein
2021-10-16 23:25 ` Pavel Begunkov [this message]
2021-10-17 1:35 ` Noah Goldstein
2021-10-14 18:17 ` [PATCH for-next 0/8] read/write cleanup Jens Axboe
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