From: "Ahmed S. Darwish" <a.darwish@linutronix.de>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
"Paul E. McKenney" <paulmck@kernel.org>,
"Sebastian A. Siewior" <bigeasy@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
Jonathan Corbet <corbet@lwn.net>,
linux-doc@vger.kernel.org
Subject: Re: [PATCH v4 01/24] Documentation: locking: Describe seqlock design and usage
Date: Tue, 21 Jul 2020 07:34:53 +0200 [thread overview]
Message-ID: <20200721053453.GA27648@lx-t490> (raw)
In-Reply-To: <20200720213551.5ba9bc6d@oasis.local.home>
On Mon, Jul 20, 2020 at 09:35:51PM -0400, Steven Rostedt wrote:
> On Mon, 20 Jul 2020 17:55:07 +0200
> "Ahmed S. Darwish" <a.darwish@linutronix.de> wrote:
> > +Read path, three categories:
> > +
> > +1. Normal Sequence readers which never block a writer but they must
> > + retry if a writer is in progress by detecting change in the sequence
> > + number. Writers do not wait for a sequence reader::
> > +
> > + do {
> > + seq = read_seqbegin(&foo_seqlock);
> > +
> > + /* ... [[read-side critical section]] ... */
> > +
> > + } while (read_seqretry(&foo_seqlock, seq));
> > +
> > +2. Locking readers which will wait if a writer or another locking reader
> > + is in progress. A locking reader in progress will also block a writer
> > + from entering its critical section. This read lock is
> > + exclusive. Unlike rwlock_t, only one locking reader can acquire it::
>
> Nit, but I would mention that this acts similar to a normal spin_lock,
> and even disables preeption (in the non-RT case).
will do.
Thanks,
--
Ahmed S. Darwish
Linutronix GmbH
next prev parent reply other threads:[~2020-07-21 5:34 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-19 21:45 [PATCH v1 00/25] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 09/25] Documentation: locking: Describe seqlock design and usage Ahmed S. Darwish
2020-05-22 18:01 ` Peter Zijlstra
2020-05-22 22:24 ` Steven Rostedt
2020-05-25 10:50 ` Ahmed S. Darwish
2020-05-25 11:02 ` Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 10/25] seqlock: Add RST directives to kernel-doc code samples and notes Ahmed S. Darwish
2020-05-22 18:02 ` Peter Zijlstra
2020-05-22 18:03 ` Peter Zijlstra
2020-05-22 18:26 ` Thomas Gleixner
2020-05-22 18:32 ` Peter Zijlstra
2020-05-25 9:36 ` Ahmed S. Darwish
2020-05-25 13:44 ` Peter Zijlstra
2020-05-25 14:07 ` Peter Zijlstra
2020-05-19 21:45 ` [PATCH v1 11/25] seqlock: Add missing kernel-doc annotations Ahmed S. Darwish
2020-05-19 21:45 ` [PATCH v1 12/25] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 00/18] " Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 01/18] Documentation: locking: Describe seqlock design and usage Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 02/18] seqlock: Properly format kernel-doc code samples Ahmed S. Darwish
2020-06-08 0:57 ` [PATCH v2 03/18] seqlock: Add missing kernel-doc annotations Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 00/20] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 01/20] Documentation: locking: Describe seqlock design and usage Ahmed S. Darwish
2020-07-06 21:04 ` Peter Zijlstra
2020-07-06 21:12 ` Jonathan Corbet
2020-07-06 21:16 ` Peter Zijlstra
2020-07-07 10:12 ` Ahmed S. Darwish
2020-07-07 12:47 ` Peter Zijlstra
2020-06-30 5:44 ` [PATCH v3 02/20] seqlock: Properly format kernel-doc code samples Ahmed S. Darwish
2020-06-30 5:44 ` [PATCH v3 03/20] seqlock: Add missing kernel-doc annotations Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 00/24] seqlock: Extend seqcount API with associated locks Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 01/24] Documentation: locking: Describe seqlock design and usage Ahmed S. Darwish
2020-07-21 1:35 ` Steven Rostedt
2020-07-21 1:37 ` Steven Rostedt
2020-07-21 5:34 ` Ahmed S. Darwish [this message]
2020-07-21 1:44 ` Steven Rostedt
2020-07-21 1:51 ` Steven Rostedt
2020-07-21 7:15 ` Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 02/24] seqlock: Properly format kernel-doc code samples Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 03/24] seqlock: seqcount_t latch: End read sections with read_seqcount_retry() Ahmed S. Darwish
2020-07-20 15:55 ` [PATCH v4 05/24] seqlock: Add kernel-doc for seqcount_t and seqlock_t APIs Ahmed S. Darwish
2020-07-20 16:49 ` [PATCH v4 00/24] seqlock: Extend seqcount API with associated locks Eric Biggers
2020-07-20 17:33 ` Ahmed S. Darwish
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