From: Linus Torvalds <torvalds@linux-foundation.org>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Boqun Feng <boqun.feng@gmail.com>,
Jonas Oberhauser <jonas.oberhauser@huaweicloud.com>,
linux-kernel@vger.kernel.org, rcu@vger.kernel.org,
linux-mm@kvack.org, lkmm@lists.linux.dev,
"Paul E. McKenney" <paulmck@kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Neeraj Upadhyay <neeraj.upadhyay@kernel.org>,
Joel Fernandes <joel@joelfernandes.org>,
Josh Triplett <josh@joshtriplett.org>,
"Uladzislau Rezki (Sony)" <urezki@gmail.com>,
rostedt <rostedt@goodmis.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Zqiang <qiang.zhang1211@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
Waiman Long <longman@redhat.com>,
Mark Rutland <mark.rutland@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Kent Overstreet <kent.overstreet@gmail.com>,
Vlastimil Babka <vbabka@suse.cz>,
maged.michael@gmail.com,
Neeraj Upadhyay <neeraj.upadhyay@amd.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [RFC PATCH 1/4] hazptr: Add initial implementation of hazard pointers
Date: Fri, 27 Sep 2024 10:23:24 -0700 [thread overview]
Message-ID: <CAHk-=wgBgh5U+dyNaN=+XCdcm2OmgSRbcH4Vbtk8i5ZDGwStSA@mail.gmail.com> (raw)
In-Reply-To: <7e1c8a5e-c110-414c-8fb2-022eacc2bd4a@efficios.com>
On Fri, 27 Sept 2024 at 10:17, Mathieu Desnoyers
<mathieu.desnoyers@efficios.com> wrote:
>
> The barrier() is ineffective at fixing the issue.
> It does not prevent the compiler CSE from losing the
> address dependency:
Ok. Thanks for actually specifying code.
That needs to be
(a) in a comment
(b) the value barrier needs to be on *both* values so that the order
of the equality testing doesn't matter.
> I'm preparing a small series that aims to show how a minimal
> hazard pointer implementation can help improve common scenarios:
I want actual numbers on real loads. Just so you know. Not "this can
help". But "this actually really _does_ help".
Linus
next prev parent reply other threads:[~2024-09-27 17:32 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-17 14:33 [RFC PATCH 0/4] Add hazard pointers to kernel Boqun Feng
2024-09-17 14:33 ` [RFC PATCH 1/4] hazptr: Add initial implementation of hazard pointers Boqun Feng
2024-09-18 8:27 ` Mathieu Desnoyers
2024-09-18 15:17 ` Alan Huang
2024-09-19 6:56 ` Boqun Feng
2024-09-19 18:07 ` Jonas Oberhauser
2024-09-19 0:12 ` Jann Horn
2024-09-19 20:30 ` Jonas Oberhauser
2024-09-20 7:43 ` Jonas Oberhauser
2024-09-19 6:39 ` Lai Jiangshan
2024-09-19 7:10 ` Boqun Feng
2024-09-19 12:33 ` Alan Huang
2024-09-19 13:57 ` Alan Huang
2024-09-19 18:58 ` Boqun Feng
2024-09-19 19:53 ` Alan Huang
2024-09-19 16:10 ` Alan Huang
2024-09-19 14:00 ` Jonas Oberhauser
2024-09-20 7:41 ` Jonas Oberhauser
2024-09-25 10:02 ` Boqun Feng
2024-09-25 10:11 ` Jonas Oberhauser
2024-09-25 10:45 ` Boqun Feng
2024-09-25 11:59 ` Mathieu Desnoyers
2024-09-25 12:16 ` Boqun Feng
2024-09-25 12:47 ` Mathieu Desnoyers
2024-09-25 13:10 ` Mathieu Desnoyers
2024-09-25 13:20 ` Mathieu Desnoyers
2024-09-26 6:16 ` Mathieu Desnoyers
2024-09-26 15:53 ` Jonas Oberhauser
2024-09-26 16:12 ` Linus Torvalds
2024-09-26 16:40 ` Jonas Oberhauser
2024-09-26 16:54 ` Linus Torvalds
2024-09-27 0:01 ` Boqun Feng
2024-09-27 1:30 ` Mathieu Desnoyers
2024-09-27 1:37 ` Boqun Feng
2024-09-27 4:28 ` Boqun Feng
2024-09-27 10:59 ` Mathieu Desnoyers
2024-09-27 14:43 ` Mathieu Desnoyers
2024-09-27 15:22 ` Mathieu Desnoyers
2024-09-27 16:06 ` Alan Huang
2024-09-27 16:44 ` Linus Torvalds
2024-09-27 17:15 ` Mathieu Desnoyers
2024-09-27 17:23 ` Linus Torvalds [this message]
2024-09-27 17:51 ` Mathieu Desnoyers
2024-09-27 18:13 ` Linus Torvalds
2024-09-27 19:12 ` Jonas Oberhauser
2024-09-27 19:28 ` Linus Torvalds
2024-09-27 20:24 ` Linus Torvalds
2024-09-27 20:02 ` Mathieu Desnoyers
2024-09-27 1:20 ` Mathieu Desnoyers
2024-09-27 4:38 ` Boqun Feng
2024-09-27 19:23 ` Jonas Oberhauser
2024-09-27 20:10 ` Mathieu Desnoyers
2024-09-27 22:18 ` Jonas Oberhauser
2024-09-28 22:10 ` Alan Huang
2024-09-28 23:12 ` Alan Huang
2024-09-25 12:19 ` Jonas Oberhauser
2024-09-17 14:34 ` [RFC PATCH 2/4] refscale: Add benchmarks for hazptr Boqun Feng
2024-09-17 14:34 ` [RFC PATCH 3/4] refscale: Add benchmarks for percpu_ref Boqun Feng
2024-09-17 14:34 ` [RFC PATCH 4/4] WIP: hazptr: Add hazptr test sample Boqun Feng
2024-09-18 7:18 ` [RFC PATCH 0/4] Add hazard pointers to kernel Linus Torvalds
2024-09-18 22:44 ` Neeraj Upadhyay
2024-09-19 6:46 ` Linus Torvalds
2024-09-20 5:00 ` Neeraj Upadhyay
2024-09-19 14:30 ` Mateusz Guzik
2024-09-19 14:14 ` Christoph Hellwig
2024-09-19 14:21 ` Linus Torvalds
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