From: Pavel Begunkov <[email protected]>
To: Jens Axboe <[email protected]>, [email protected]
Subject: Re: [PATCH for-next 1/7] io_uring: use user visible tail in io_uring_poll()
Date: Mon, 23 Jan 2023 20:56:54 +0000 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 1/23/23 18:25, Jens Axboe wrote:
> On 1/23/23 7:37 AM, Pavel Begunkov wrote:
>> We return POLLIN from io_uring_poll() depending on whether there are
>> CQEs for the userspace, and so we should use the user visible tail
>> pointer instead of a transient cached value.
>
> Should we mark this one for stable as well?
Yeah, we can. It makes it to overestimate the number of ready CQEs
and causes spurious POLLINs, but should be extremely rare and happen
only on queue (but not wq wake up).
--
Pavel Begunkov
next prev parent reply other threads:[~2023-01-23 20:58 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-23 14:37 [PATCH for-next 0/7] normal tw optimisation + refactoring Pavel Begunkov
2023-01-23 14:37 ` [PATCH for-next 1/7] io_uring: use user visible tail in io_uring_poll() Pavel Begunkov
2023-01-23 18:25 ` Jens Axboe
2023-01-23 20:56 ` Pavel Begunkov [this message]
2023-01-23 21:09 ` Jens Axboe
2023-01-23 14:37 ` [PATCH for-next 2/7] io_uring: kill outdated comment about overflow flush Pavel Begunkov
2023-01-23 14:37 ` [PATCH for-next 3/7] io_uring: improve io_get_sqe Pavel Begunkov
2023-01-23 14:37 ` [PATCH for-next 4/7] io_uring: refactor req allocation Pavel Begunkov
2023-01-23 14:37 ` [PATCH for-next 5/7] io_uring: refactor io_put_task helpers Pavel Begunkov
2023-01-23 14:37 ` [PATCH for-next 6/7] io_uring: refactor tctx_task_work Pavel Begunkov
2023-01-23 14:37 ` [PATCH for-next 7/7] io_uring: return normal tw run linking optimisation Pavel Begunkov
2023-01-23 21:14 ` [PATCH for-next 0/7] normal tw optimisation + refactoring Jens Axboe
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