From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
Bradley Morgan <brads@mainlining.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>,
rcu@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-team@meta.com, Boqun Feng <boqun@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
lkmm@lists.linux.dev, Zqiang <qiang.zhang@linux.dev>,
Wang Lian <lianux.mm@gmail.com>,
Kunwu Chan <kunwu.chan@gmail.com>,
Nicholas Piggin <npiggin@gmail.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Will Deacon <will@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Alan Stern <stern@rowland.harvard.edu>,
John Stultz <jstultz@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Frederic Weisbecker <frederic@kernel.org>,
Joel Fernandes <joel@joelfernandes.org>,
Josh Triplett <josh@joshtriplett.org>,
Uladzislau Rezki <urezki@gmail.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Zqiang <qiang.zhang1211@gmail.com>,
Ingo Molnar <mingo@redhat.com>, Waiman Long <longman@redhat.com>,
Mark Rutland <mark.rutland@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Vlastimil Babka <vbabka@suse.cz>,
maged.michael@gmail.com, Mateusz Guzik <mjguzik@gmail.com>,
Jonas Oberhauser <jonas.oberhauser@huaweicloud.com>,
linux-mm@kvack.org
Subject: Re: [PATCH 01/28] hazptr: Implement Hazard Pointers
Date: Sat, 19 Sep 2026 13:19:09 -0400 [thread overview]
Message-ID: <c0de0530-e919-4cb8-89de-56a20a8a09fc@efficios.com> (raw)
In-Reply-To: <CAHk-=wjyniJy-CX1muCrsZp-i-sLGRYeRYEPN7sw9orRZUCwag@mail.gmail.com>
On 2026-09-19 13:00, Linus Torvalds wrote:
[...]
> Now, obviously, the thing that would impress me is something like the
> dcache. If *that* can be converted, and it shows real improvements on
> some real benchmark, then I'm sold.
[ Side-discussion, not related to hazard pointers. ]
Talking about dcache improvements:
I've been working on scalability of rename, directory move, and
directory listing, basically killing dcache global locks, seqlocks
and rwlocks which significantly limit dcache update and read-side
scalability.
Those improvements are based on RCU, not hazard pointers, and on a new
"RCU pseudo-transaction" concept I've invented earlier this year.
I'm preparing a paper and I plan to present it at LPC in Prague.
My benchmark results are on a userspace port of the Linux kernel dentry
cache at this point, so it's not ready for anything close to upstream at
this stage.
Cheers,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com
next prev parent reply other threads:[~2026-09-19 17:19 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-18 23:59 [PATCH RFC v3 0/28] Simple hazard-pointer implementation and torture tests Paul E. McKenney
2026-09-19 0:00 ` [PATCH 01/28] hazptr: Implement Hazard Pointers Paul E. McKenney
2026-09-19 11:12 ` Bradley Morgan
2026-09-19 16:30 ` Linus Torvalds
2026-09-19 16:34 ` Bradley Morgan
2026-09-19 17:00 ` Linus Torvalds
2026-09-19 17:09 ` Mathieu Desnoyers
2026-09-19 18:09 ` Boqun Feng
2026-09-19 17:19 ` Mathieu Desnoyers [this message]
2026-09-19 18:18 ` Paul E. McKenney
2026-09-19 23:58 ` Bradley Morgan
2026-09-19 16:41 ` Bradley Morgan
2026-09-19 17:56 ` Paul E. McKenney
2026-09-19 0:00 ` [PATCH 02/28] hazptr: Add refscale test Paul E. McKenney
2026-09-19 0:00 ` [PATCH 03/28] torture: Add a hazptrtorture.c torture test Paul E. McKenney
2026-09-19 0:00 ` [PATCH 04/28] hazptrtorture: Add testing of on-stack hazptr_ctx structures Paul E. McKenney
2026-09-19 0:00 ` [PATCH 05/28] hazptrtorture: Add microsecond-scale sleep in readers Paul E. McKenney
2026-09-19 0:00 ` [PATCH 06/28] hazptrtorture: Enable system-independent CPU overcommit Paul E. McKenney
2026-09-19 0:00 ` [PATCH 07/28] torture: Add a stutter_will_wait() function Paul E. McKenney
2026-09-19 0:00 ` [PATCH 08/28] hazptrtorture: Use mnemonic local variables for context information Paul E. McKenney
2026-09-19 0:00 ` [PATCH 09/28] hazptrtorture: Split hazptr_torture_reader_tail() from hazptr_torture_reader() Paul E. McKenney
2026-09-19 0:00 ` [PATCH 10/28] hazptrtorture: Add kthread to release deferred hazard pointers Paul E. McKenney
2026-09-19 0:00 ` [PATCH 11/28] hazptrtorture: Defer release of " Paul E. McKenney
2026-09-19 0:00 ` [PATCH 12/28] hazptrtorture: Add irq_acquire to acquire hazptr from irq Paul E. McKenney
2026-09-19 0:00 ` [PATCH 13/28] hazptrtorture: Use task_state_to_char() for task-state reporting Paul E. McKenney
2026-09-19 0:00 ` [PATCH 14/28] hazptrtorture: Pass hazptr_pending to hazptr_torture_reader_tail() Paul E. McKenney
2026-09-19 0:00 ` [PATCH 15/28] hazptrtorture: Add the ability to disable the writer kthread Paul E. McKenney
2026-09-19 0:00 ` [PATCH 16/28] hazptrtorture: Add irq_release to release hazptr from irq Paul E. McKenney
2026-09-19 0:00 ` [PATCH 17/28] hazptrtorture: Accumulate operation statistics Paul E. McKenney
2026-09-19 0:00 ` [PATCH 18/28] doc: Add hazptrtorture module parameters Paul E. McKenney
2026-09-19 0:00 ` [PATCH 19/28] hazptr: Permit detaching hazard pointers from contexts Paul E. McKenney
2026-09-19 11:42 ` Boqun Feng
2026-09-19 11:43 ` Boqun Feng
2026-09-19 0:00 ` [PATCH 20/28] hazptrtorture: Detach deferred and IPIed hazard pointers Paul E. McKenney
2026-09-19 0:00 ` [PATCH 21/28] hazptr: Introduce CONFIG_HAZPTR_DEBUG misuse detection Paul E. McKenney
2026-09-19 0:00 ` [PATCH 22/28] hazptrtorture: Fix hazptr ownership issue Paul E. McKenney
2026-09-19 0:00 ` [PATCH 23/28] hazptrtorture: Enable CONFIG_HAZPTR_DEBUG Paul E. McKenney
2026-09-19 0:00 ` [PATCH 24/28] hazptr: Upgrade kernel-doc headers Paul E. McKenney
2026-09-19 0:00 ` [PATCH 25/28] hazptrtorture: Fix inverted sleep condition in do_pending kthread Paul E. McKenney
2026-09-19 0:00 ` [PATCH 26/28] hazptr: Implement two-phase wildcard scan Paul E. McKenney
2026-09-19 13:28 ` Boqun Feng
2026-09-20 12:46 ` Mathieu Desnoyers
2026-09-20 15:55 ` Boqun Feng
2026-09-25 19:08 ` Mathieu Desnoyers
2026-09-20 14:46 ` Gary Guo
2026-09-20 15:44 ` Mathieu Desnoyers
2026-09-20 15:57 ` Gary Guo
2026-09-25 19:19 ` Mathieu Desnoyers
2026-09-25 20:17 ` Gary Guo
2026-09-25 20:18 ` Mathieu Desnoyers
2026-09-19 0:00 ` [PATCH 27/28] hazptr: handle NULL address in hazptr_detach Paul E. McKenney
2026-09-19 0:00 ` [PATCH 28/28] torture.sh: Add hazptr torturing Paul E. McKenney
2026-09-19 11:18 ` Bradley Morgan
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