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From: Jens Axboe <axboe@kernel.dk>
To: "Christian A. Ehrhardt" <lk@c--e.de>
Cc: Tip ten Brink <tip@tenbrinkmeijs.com>,
	io-uring@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iouring: Fix min_timeout behaviour
Date: Sat, 6 Jun 2026 15:55:18 -0600	[thread overview]
Message-ID: <9f94f066-ea36-443e-b989-cf920ff9d27e@kernel.dk> (raw)
In-Reply-To: <20260606201120.1441447-1-lk@c--e.de>

On 6/6/26 2:11 PM, Christian A. Ehrhardt wrote:
> The wakeup condition if a min timeout is present and has
> expired is that at least _one_ CQE was posted. Thus set
> the cq_tail target to ->cq_min_tail + 1. Without this
> commit a spurious wakeup can result in a premature wakeup
> because io_should_wake() will return true even if _no_ CQE
> was posted at all.
> 
> Tested by running the liburing testsuite with no regressions.
> 
> Additionally, tested by turning all calls to schedule() in
> io_uring/wait.c into calls to schedule_timeout(1) to force
> the spurious wakeups. With these spurious wakeups the
> min-timeout.t test fails before and passes after this commit.

Either this or the test case is broken, with or without the change
you sent for the test case. I'll take a look, but it's definitely
not passing as-is.

-- 
Jens Axboe


  reply	other threads:[~2026-06-06 21:55 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-06 20:11 [PATCH] iouring: Fix min_timeout behaviour Christian A. Ehrhardt
2026-06-06 21:55 ` Jens Axboe [this message]
2026-06-07 10:40   ` Christian A. Ehrhardt
2026-06-07 22:13 ` Jens Axboe

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