From: Pavel Begunkov <[email protected]>
To: "Jens Axboe" <[email protected]>, "Carter Li 李通洲" <[email protected]>
Cc: Peter Zijlstra <[email protected]>,
io-uring <[email protected]>
Subject: Re: [ISSUE] The time cost of IOSQE_IO_LINK
Date: Sun, 16 Feb 2020 22:06:53 +0300 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
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On 15/02/2020 09:01, Jens Axboe wrote:
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index fb94b8bac638..530dcd91fa53 100644
> @@ -4630,6 +4753,14 @@ static void __io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe)
> */
> if (ret == -EAGAIN && (!(req->flags & REQ_F_NOWAIT) ||
> (req->flags & REQ_F_MUST_PUNT))) {
> +
> + if (io_arm_poll_handler(req, &retry_count)) {
> + if (retry_count == 1)
> + goto issue;
Better to sqe=NULL before retrying, so it won't re-read sqe and try to init the
req twice.
Also, the second sync-issue may -EAGAIN again, and as I remember, read/write/etc
will try to copy iovec into req->io. But iovec is already in req->io, so it will
self memcpy(). Not a good thing.
> + else if (!retry_count)
> + goto done_req;
> + INIT_IO_WORK(&req->work, io_wq_submit_work);
It's not nice to reset it as this:
- prep() could set some work.flags
- custom work.func is more performant (adds extra switch)
- some may rely on specified work.func to be called. e.g. close(), even though
it doesn't participate in the scheme
> + }
> punt:
> if (io_op_defs[req->opcode].file_table) {
> ret = io_grab_files(req);
> @@ -5154,26 +5285,40 @@ void io_uring_task_handler(struct task_struct *tsk)
> {
> LIST_HEAD(local_list);
> struct io_kiocb *req;
> + long state;
>
> spin_lock_irq(&tsk->uring_lock);
> if (!list_empty(&tsk->uring_work))
--
Pavel Begunkov
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next prev parent reply other threads:[~2020-02-16 19:07 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-12 16:31 [ISSUE] The time cost of IOSQE_IO_LINK Carter Li 李通洲
2020-02-12 17:11 ` Jens Axboe
2020-02-12 17:22 ` Jens Axboe
2020-02-12 17:29 ` Jens Axboe
2020-02-13 0:33 ` Carter Li 李通洲
2020-02-13 15:08 ` Pavel Begunkov
2020-02-13 15:14 ` Jens Axboe
2020-02-13 15:51 ` Carter Li 李通洲
2020-02-14 1:25 ` Carter Li 李通洲
2020-02-14 2:45 ` Jens Axboe
2020-02-14 5:03 ` Jens Axboe
2020-02-14 15:32 ` Peter Zijlstra
2020-02-14 15:47 ` Jens Axboe
2020-02-14 16:18 ` Jens Axboe
2020-02-14 17:52 ` Jens Axboe
2020-02-14 20:44 ` Jens Axboe
2020-02-15 0:16 ` Carter Li 李通洲
2020-02-15 1:10 ` Jens Axboe
2020-02-15 1:25 ` Carter Li 李通洲
2020-02-15 1:27 ` Jens Axboe
2020-02-15 6:01 ` Jens Axboe
2020-02-15 6:32 ` Carter Li 李通洲
2020-02-15 15:11 ` Jens Axboe
2020-02-16 19:06 ` Pavel Begunkov [this message]
2020-02-16 22:23 ` Jens Axboe
2020-02-17 10:30 ` Pavel Begunkov
2020-02-17 19:30 ` Jens Axboe
2020-02-16 23:06 ` Jens Axboe
2020-02-16 23:07 ` Jens Axboe
2020-02-17 12:09 ` Peter Zijlstra
2020-02-17 16:12 ` Jens Axboe
2020-02-17 17:16 ` Jens Axboe
2020-02-17 17:46 ` Peter Zijlstra
2020-02-17 18:16 ` Jens Axboe
2020-02-18 13:13 ` Peter Zijlstra
2020-02-18 14:27 ` [PATCH] asm-generic/atomic: Add try_cmpxchg() fallbacks Peter Zijlstra
2020-02-18 14:40 ` Peter Zijlstra
2020-02-20 10:30 ` Will Deacon
2020-02-20 10:37 ` Peter Zijlstra
2020-02-20 10:39 ` Will Deacon
2020-02-18 14:56 ` [ISSUE] The time cost of IOSQE_IO_LINK Oleg Nesterov
2020-02-18 15:07 ` Oleg Nesterov
2020-02-18 15:38 ` Peter Zijlstra
2020-02-18 16:33 ` Jens Axboe
2020-02-18 15:07 ` Peter Zijlstra
2020-02-18 15:50 ` [PATCH] task_work_run: don't take ->pi_lock unconditionally Oleg Nesterov
2020-02-20 16:39 ` Peter Zijlstra
2020-02-20 17:22 ` Oleg Nesterov
2020-02-20 17:49 ` Peter Zijlstra
2020-02-21 14:52 ` Oleg Nesterov
2020-02-24 18:47 ` Jens Axboe
2020-02-28 19:17 ` Jens Axboe
2020-02-28 19:25 ` Peter Zijlstra
2020-02-28 19:28 ` Jens Axboe
2020-02-28 20:06 ` Peter Zijlstra
2020-02-28 20:15 ` Jens Axboe
2020-02-18 16:46 ` [ISSUE] The time cost of IOSQE_IO_LINK Jens Axboe
2020-02-18 16:52 ` Jens Axboe
2020-02-18 13:13 ` Peter Zijlstra
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