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 7/8] io_uring: arm poll for non-nowait files
Date: Sun, 17 Oct 2021 00:16:57 +0100 [thread overview]
Message-ID: <dcc08d20-fd0c-e4d2-6500-2139aca4903e@gmail.com> (raw)
In-Reply-To: <CAFUsyfLH46EOJHvGJRToE0GApdjdX4UhO7DgnV9S4di4O1CCMQ@mail.gmail.com>
On 10/16/21 23:57, Noah Goldstein wrote:
> On Sat, Oct 16, 2021 at 5:19 PM Pavel Begunkov <asml.silence@gmail.com> wrote:
>> @@ -3238,7 +3220,8 @@ static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter)
>> */
>> if (kiocb->ki_flags & IOCB_HIPRI)
>> return -EOPNOTSUPP;
>> - if (kiocb->ki_flags & IOCB_NOWAIT)
>> + if ((kiocb->ki_flags & IOCB_NOWAIT) &&
>> + !(kiocb->ki_filp->f_flags & O_NONBLOCK))
>> return -EAGAIN;
>
> Instead of 2x branches on what appears to be the error (not hot path)
The whole loop_rw_iter() is a slow path, we don't care enough
--
Pavel Begunkov
next prev parent reply other threads:[~2021-10-16 23:17 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-15 16:09 [PATCH for-next 0/8] further rw cleanups+optimisisation Pavel Begunkov
2021-10-15 16:09 ` [PATCH 1/8] io_uring: optimise req->ctx reloads Pavel Begunkov
2021-10-15 16:09 ` [PATCH 2/8] io_uring: kill io_wq_current_is_worker() in iopoll Pavel Begunkov
2021-10-15 16:09 ` [PATCH 3/8] io_uring: optimise io_import_iovec fixed path Pavel Begunkov
2021-10-15 16:09 ` [PATCH 4/8] io_uring: return iovec from __io_import_iovec Pavel Begunkov
2021-10-15 16:09 ` [PATCH 5/8] io_uring: optimise fixed rw rsrc node setting Pavel Begunkov
2021-10-15 16:09 ` [PATCH 6/8] io_uring: clean io_prep_rw() Pavel Begunkov
2021-10-15 16:09 ` [PATCH 7/8] io_uring: arm poll for non-nowait files Pavel Begunkov
2021-10-16 22:57 ` Noah Goldstein
2021-10-16 23:16 ` Pavel Begunkov [this message]
2021-10-15 16:09 ` [PATCH 8/8] io_uring: simplify io_file_supports_nowait() Pavel Begunkov
2021-10-16 3:36 ` [PATCH for-next 0/8] further rw cleanups+optimisisation Jens Axboe
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