From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org,
"André Almeida" <andrealmeid@igalia.com>,
"Darren Hart" <dvhart@infradead.org>,
"Davidlohr Bueso" <dave@stgolabs.net>,
"Ingo Molnar" <mingo@redhat.com>,
"Juri Lelli" <juri.lelli@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Valentin Schneider" <vschneid@redhat.com>,
"Waiman Long" <longman@redhat.com>
Subject: Re: [PATCH v12 00/21] futex: Add support task local hash maps, FUTEX2_NUMA and FUTEX2_MPOL
Date: Fri, 9 May 2025 13:41:05 +0200 [thread overview]
Message-ID: <20250509114105.HZdDPPO5@linutronix.de> (raw)
In-Reply-To: <20250506073611.GH4198@noisy.programming.kicks-ass.net>
On 2025-05-06 09:36:11 [+0200], Peter Zijlstra wrote:
> Well, if you do stupid things, you get to keep the pieces or something
> along those lines. Same as when userspace goes scribble the node value
> while another thread is waiting and all that.
>
> Even with the unconditional write back you're going to have a problem
> with concurrent wait on the same futex.
We could add a global lock for the write back case to ensure there is
only one at a time. However let me document the current behaviour of the
new pieces and tick it off ;)
Sebastian
prev parent reply other threads:[~2025-05-09 11:42 UTC|newest]
Thread overview: 109+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-16 16:29 [PATCH v12 00/21] futex: Add support task local hash maps, FUTEX2_NUMA and FUTEX2_MPOL Sebastian Andrzej Siewior
2025-04-16 16:29 ` [PATCH v12 01/21] rcuref: Provide rcuref_is_dead() Sebastian Andrzej Siewior
2025-05-05 21:09 ` André Almeida
2025-05-08 10:34 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-04-16 16:29 ` [PATCH v12 02/21] mm: Add vmalloc_huge_node() Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Peter Zijlstra
2025-04-16 16:29 ` [PATCH v12 03/21] futex: Move futex_queue() into futex_wait_setup() Sebastian Andrzej Siewior
2025-05-05 21:43 ` André Almeida
2025-05-16 12:53 ` Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Peter Zijlstra
2025-04-16 16:29 ` [PATCH v12 04/21] futex: Pull futex_hash() out of futex_q_lock() Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Peter Zijlstra
2025-04-16 16:29 ` [PATCH v12 05/21] futex: Create hb scopes Sebastian Andrzej Siewior
2025-05-06 23:45 ` André Almeida
2025-05-16 12:20 ` Sebastian Andrzej Siewior
2025-05-16 13:23 ` Peter Zijlstra
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Peter Zijlstra
2025-04-16 16:29 ` [PATCH v12 06/21] futex: Create futex_hash() get/put class Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Peter Zijlstra
2025-04-16 16:29 ` [PATCH v12 07/21] futex: Create private_hash() " Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Peter Zijlstra
2025-04-16 16:29 ` [PATCH v12 08/21] futex: Acquire a hash reference in futex_wait_multiple_setup() Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-04-16 16:29 ` [PATCH v12 09/21] futex: Decrease the waiter count before the unlock operation Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-04-16 16:29 ` [PATCH v12 10/21] futex: Introduce futex_q_lockptr_lock() Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-05-08 19:06 ` [PATCH v12 10/21] " André Almeida
2025-05-16 12:18 ` Sebastian Andrzej Siewior
2025-04-16 16:29 ` [PATCH v12 11/21] futex: Create helper function to initialize a hash slot Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-04-16 16:29 ` [PATCH v12 12/21] futex: Add basic infrastructure for local task local hash Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-04-16 16:29 ` [PATCH v12 13/21] futex: Allow automatic allocation of process wide futex hash Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-04-16 16:29 ` [PATCH v12 14/21] futex: Allow to resize the private local hash Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-05-08 20:32 ` [PATCH v12 14/21] " André Almeida
2025-05-16 10:49 ` Sebastian Andrzej Siewior
2025-05-16 13:00 ` André Almeida
2025-05-10 8:45 ` [PATCH] futex: Fix futex_mm_init() build failure on older compilers, remove rcu_assign_pointer() Ingo Molnar
2025-05-11 8:11 ` [tip: locking/futex] futex: Relax the rcu_assign_pointer() assignment of mm->futex_phash in futex_mm_init() tip-bot2 for Ingo Molnar
2025-06-01 7:39 ` [PATCH v12 14/21] futex: Allow to resize the private local hash Lai, Yi
2025-06-02 11:00 ` Sebastian Andrzej Siewior
2025-06-02 14:36 ` Lai, Yi
2025-06-02 14:44 ` Sebastian Andrzej Siewior
2025-06-02 15:00 ` Lai, Yi
2025-06-11 9:20 ` [tip: locking/urgent] " tip-bot2 for Sebastian Andrzej Siewior
2025-06-11 14:39 ` tip-bot2 for Sebastian Andrzej Siewior
2025-06-11 14:43 ` Sebastian Andrzej Siewior
2025-06-11 15:11 ` Peter Zijlstra
2025-06-11 15:20 ` Peter Zijlstra
2025-06-11 15:35 ` Sebastian Andrzej Siewior
2025-06-16 17:14 ` Calvin Owens
2025-06-17 7:16 ` Sebastian Andrzej Siewior
2025-06-17 9:23 ` Calvin Owens
2025-06-17 9:50 ` Sebastian Andrzej Siewior
2025-06-17 16:11 ` Calvin Owens
2025-06-18 2:15 ` Calvin Owens
2025-06-18 16:47 ` Sebastian Andrzej Siewior
2025-06-18 16:03 ` Sebastian Andrzej Siewior
2025-06-18 16:49 ` Calvin Owens
2025-06-18 17:09 ` Sebastian Andrzej Siewior
2025-06-18 20:56 ` Calvin Owens
2025-06-18 22:47 ` Calvin Owens
2025-06-19 21:07 ` Calvin Owens
2025-06-20 10:31 ` Sebastian Andrzej Siewior
2025-06-20 18:56 ` Calvin Owens
2025-06-21 1:02 ` Calvin Owens
2025-06-21 7:24 ` Calvin Owens
2025-06-21 21:01 ` Sebastian Andrzej Siewior
2025-06-22 16:17 ` Calvin Owens
2025-04-16 16:29 ` [PATCH v12 15/21] futex: Allow to make the private hash immutable Sebastian Andrzej Siewior
2025-05-02 18:01 ` Peter Zijlstra
2025-05-05 7:14 ` Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-04-16 16:29 ` [PATCH v12 16/21] futex: Implement FUTEX2_NUMA Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Peter Zijlstra
2025-04-16 16:29 ` [PATCH v12 17/21] futex: Implement FUTEX2_MPOL Sebastian Andrzej Siewior
2025-05-02 18:45 ` Peter Zijlstra
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Peter Zijlstra
2025-04-16 16:29 ` [PATCH v12 18/21] tools headers: Synchronize prctl.h ABI header Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-04-16 16:29 ` [PATCH v12 19/21] tools/perf: Allow to select the number of hash buckets Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-04-16 16:29 ` [PATCH v12 20/21] selftests/futex: Add futex_priv_hash Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-05-09 21:22 ` [PATCH v12 20/21] " André Almeida
2025-05-16 7:38 ` Sebastian Andrzej Siewior
2025-05-27 11:28 ` Mark Brown
2025-05-27 12:23 ` Sebastian Andrzej Siewior
2025-05-27 12:35 ` Mark Brown
2025-05-27 12:43 ` Sebastian Andrzej Siewior
2025-05-27 12:59 ` Mark Brown
2025-05-27 13:25 ` Sebastian Andrzej Siewior
2025-05-27 13:40 ` Mark Brown
2025-05-27 13:45 ` Sebastian Andrzej Siewior
2025-04-16 16:29 ` [PATCH v12 21/21] selftests/futex: Add futex_numa_mpol Sebastian Andrzej Siewior
2025-05-02 19:08 ` Peter Zijlstra
2025-05-05 7:33 ` Sebastian Andrzej Siewior
2025-05-02 19:16 ` Peter Zijlstra
2025-05-05 7:36 ` Sebastian Andrzej Siewior
2025-05-08 10:33 ` [tip: locking/futex] " tip-bot2 for Sebastian Andrzej Siewior
2025-04-16 16:31 ` [PATCH v12 00/21] futex: Add support task local hash maps, FUTEX2_NUMA and FUTEX2_MPOL Sebastian Andrzej Siewior
2025-05-02 19:48 ` Peter Zijlstra
2025-05-03 10:09 ` Peter Zijlstra
2025-05-05 7:30 ` Sebastian Andrzej Siewior
2025-05-06 7:36 ` Peter Zijlstra
2025-05-09 11:41 ` Sebastian Andrzej Siewior [this message]
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