From: Peter Zijlstra <peterz@infradead.org>
To: linux-kernel@vger.kernel.org
Cc: linux-tip-commits@vger.kernel.org, Jann Horn <jannh@google.com>,
Ingo Molnar <mingo@kernel.org>,
x86@kernel.org
Subject: Re: [tip: locking/core] locking/mutex: Document that mutex_unlock() is non-atomic
Date: Fri, 1 Dec 2023 13:18:08 +0100 [thread overview]
Message-ID: <20231201121808.GL3818@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <170142744948.398.4203675877225809071.tip-bot2@tip-bot2>
On Fri, Dec 01, 2023 at 10:44:09AM -0000, tip-bot2 for Jann Horn wrote:
> --- a/Documentation/locking/mutex-design.rst
> +++ b/Documentation/locking/mutex-design.rst
> @@ -101,6 +101,12 @@ features that make lock debugging easier and faster:
> - Detects multi-task circular deadlocks and prints out all affected
> locks and tasks (and only those tasks).
>
> +Releasing a mutex is not an atomic operation: Once a mutex release operation
I still object to this confusing usage of atomic. Also all this also
applies to all sleeping locks, rwsem etc. I don't see why we need to
special case mutex here.
Also completion_done() has an explicit lock+unlock on wait.lock to
deal with this there.
next prev parent reply other threads:[~2023-12-01 12:18 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-30 20:48 [PATCH] locking: Document that mutex_unlock() is non-atomic Jann Horn
2023-11-30 21:53 ` Waiman Long
2023-11-30 22:24 ` Jann Horn
2023-11-30 23:56 ` Waiman Long
2023-12-01 10:33 ` [PATCH -v2] locking/mutex: " Ingo Molnar
2023-12-02 1:37 ` Bagas Sanjaya
2023-12-01 10:20 ` [PATCH] locking: " Ingo Molnar
2023-12-01 0:33 ` Waiman Long
2023-12-01 15:01 ` Jann Horn
[not found] ` <a9e19ad0-9a27-4885-a6ac-bebd3e997b02@redhat.com>
2023-12-01 16:03 ` Jann Horn
2023-12-01 18:12 ` David Laight
2023-12-01 18:18 ` Jann Horn
[not found] ` <1bcee696-d751-413c-a2ec-4a8480bae00b@redhat.com>
[not found] ` <780e652ff52044d4a213cacbd9276cf8@AcuMS.aculab.com>
2023-12-01 19:15 ` Waiman Long
2023-12-02 15:51 ` David Laight
2023-12-02 22:39 ` Waiman Long
2023-12-01 9:10 ` Peter Zijlstra
2023-12-01 15:58 ` Jann Horn
2023-12-01 10:44 ` [tip: locking/core] locking/mutex: " tip-bot2 for Jann Horn
2023-12-01 12:18 ` Peter Zijlstra [this message]
2024-01-08 8:45 ` [PATCH] locking/mutex: Clarify that mutex_unlock(), and most other sleeping locks, cannot be used to reference-count objects Ingo Molnar
2024-01-08 9:00 ` [PATCH -v2] locking/mutex: Clarify that mutex_unlock(), and most other sleeping locks, can still use the lock object after it's unlocked Ingo Molnar
2024-01-08 15:28 ` [PATCH] locking/mutex: Clarify that mutex_unlock(), and most other sleeping locks, cannot be used to reference-count objects Jann Horn
2024-01-08 9:01 ` [tip: locking/core] locking/mutex: Clarify that mutex_unlock(), and most other sleeping locks, can still use the lock object after it's unlocked tip-bot2 for Ingo Molnar
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