From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Joel Fernandes <joel@joelfernandes.org>
Cc: linux-kernel@vger.kernel.org,
Josh Triplett <josh@joshtriplett.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
rcu@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [RFC 0/2] srcu: Remove pre-flip memory barrier
Date: Tue, 20 Dec 2022 14:01:30 -0500 [thread overview]
Message-ID: <5bd5ee4a-710a-96bc-abe8-772b2e60f478@efficios.com> (raw)
In-Reply-To: <7A9876BA-C375-42A7-A5C9-FD940D2898D7@joelfernandes.org>
On 2022-12-20 13:29, Joel Fernandes wrote:
>
> I do want to finish my memory barrier studies of SRCU over the holidays since I have been deep in the hole with that already. Back to the post flip memory barrier here since I think now even that might not be needed…
I strongly suspect the memory barrier after flip is useless for the same
reasons I mentioned explaining why the barrier before the flip is useless.
However, we need to double-check that we have memory barriers at the
beginning and end of synchronize_srcu, and between load of "unlock"
counters and load of "lock" counters.
Where is the barrier at the beginning of synchronize_srcu ?
Thanks,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com
next prev parent reply other threads:[~2022-12-20 19:01 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-18 19:13 Joel Fernandes (Google)
2022-12-18 19:13 ` [RFC 1/2] srcu: Remove comment about prior read lock counts Joel Fernandes (Google)
2022-12-18 21:08 ` Mathieu Desnoyers
2022-12-18 21:19 ` Joel Fernandes
2022-12-18 19:13 ` [RFC 2/2] srcu: Remove memory barrier "E" as it is not required Joel Fernandes (Google)
2022-12-18 21:42 ` Frederic Weisbecker
2022-12-18 23:26 ` Joel Fernandes
2022-12-19 0:30 ` Joel Fernandes
2022-12-18 20:57 ` [RFC 0/2] srcu: Remove pre-flip memory barrier Mathieu Desnoyers
2022-12-18 21:30 ` Joel Fernandes
2022-12-18 23:26 ` Paul E. McKenney
2022-12-18 23:38 ` Mathieu Desnoyers
2022-12-19 0:04 ` Joel Fernandes
2022-12-19 0:24 ` Joel Fernandes
2022-12-19 1:50 ` Mathieu Desnoyers
2022-12-20 0:55 ` Joel Fernandes
2022-12-20 1:04 ` Joel Fernandes
2022-12-20 17:00 ` Mathieu Desnoyers
2022-12-20 18:05 ` Joel Fernandes
2022-12-20 18:14 ` Mathieu Desnoyers
2022-12-20 18:29 ` Joel Fernandes
2022-12-20 19:01 ` Mathieu Desnoyers [this message]
2022-12-20 19:06 ` Joel Fernandes
2022-12-20 23:05 ` Frederic Weisbecker
2022-12-20 23:46 ` Joel Fernandes
2022-12-21 0:27 ` Frederic Weisbecker
2022-12-20 22:57 ` Frederic Weisbecker
2022-12-21 3:34 ` Mathieu Desnoyers
2022-12-21 11:59 ` Frederic Weisbecker
2022-12-21 17:11 ` Mathieu Desnoyers
2022-12-22 12:40 ` Frederic Weisbecker
2022-12-22 13:19 ` Joel Fernandes
2022-12-22 16:43 ` Paul E. McKenney
2022-12-22 18:19 ` Joel Fernandes
2022-12-22 18:53 ` Paul E. McKenney
2022-12-22 18:56 ` Joel Fernandes
2022-12-22 19:45 ` Paul E. McKenney
2022-12-23 4:43 ` Joel Fernandes
2022-12-23 16:12 ` Joel Fernandes
2022-12-23 18:15 ` Paul E. McKenney
2022-12-23 20:10 ` Joel Fernandes
2022-12-23 20:52 ` Paul E. McKenney
2022-12-20 20:55 ` Joel Fernandes
2022-12-21 3:52 ` Mathieu Desnoyers
2022-12-21 5:02 ` Joel Fernandes
2022-12-21 0:07 ` Frederic Weisbecker
2022-12-21 3:47 ` Mathieu Desnoyers
2022-12-20 4:07 ` Joel Fernandes
2022-12-20 12:34 ` Frederic Weisbecker
2022-12-20 12:40 ` Frederic Weisbecker
2022-12-20 13:44 ` Joel Fernandes
2022-12-20 14:07 ` Frederic Weisbecker
2022-12-20 14:20 ` Joel Fernandes
2022-12-20 22:44 ` Frederic Weisbecker
2022-12-21 0:15 ` Joel Fernandes
2022-12-21 0:49 ` Frederic Weisbecker
2022-12-21 0:58 ` Frederic Weisbecker
2022-12-21 3:43 ` Mathieu Desnoyers
2022-12-21 4:26 ` Joel Fernandes
2022-12-21 14:04 ` Frederic Weisbecker
2022-12-21 16:30 ` Mathieu Desnoyers
2022-12-21 12:11 ` Frederic Weisbecker
2022-12-21 17:20 ` Mathieu Desnoyers
2022-12-21 18:18 ` Joel Fernandes
2022-12-21 2:41 ` Joel Fernandes
2022-12-21 11:26 ` Frederic Weisbecker
2022-12-21 16:02 ` Boqun Feng
2022-12-21 17:30 ` Frederic Weisbecker
2022-12-21 19:33 ` Joel Fernandes
2022-12-21 19:57 ` Joel Fernandes
2022-12-21 20:19 ` Boqun Feng
2022-12-22 12:16 ` Frederic Weisbecker
2022-12-22 12:24 ` Frederic Weisbecker
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