From: Thomas Gleixner <tglx@linutronix.de>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
linux-kernel@vger.kernel.org
Cc: "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>,
"Peter Zijlstra" <peterz@infradead.org>,
"Valentin Schneider" <vschneid@redhat.com>,
"Waiman Long" <longman@redhat.com>,
"Sebastian Andrzej Siewior" <bigeasy@linutronix.de>
Subject: Re: [PATCH v9 11/11] futex: Use a hashmask instead of hashsize.
Date: Wed, 26 Feb 2025 09:17:16 +0100 [thread overview]
Message-ID: <875xkxf7cj.ffs@tglx> (raw)
In-Reply-To: <20250225170914.289358-12-bigeasy@linutronix.de>
On Tue, Feb 25 2025 at 18:09, Sebastian Andrzej Siewior wrote:
> The global hash uses futex_hashsize to save the amount of the hash
> buckets that have been allocated during system boot. On each
> futex_hash() invocation this number is substracted by one to get the
> mask. This can be optimized by saving directly the mask avoiding the
> substraction on each futex_hash() invocation.
As this is true independent of the private hash muck, this should go to
the top of the series, so it can be applied right away. Aside of that it
spares the churn in the new code ....
Thanks,
tglx
next prev parent reply other threads:[~2025-02-26 8:17 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-25 17:09 [PATCH v9 00/11] futex: Add support task local hash maps Sebastian Andrzej Siewior
2025-02-25 17:09 ` [PATCH v9 01/11] futex: fixup futex_wait_setup [fold futex: Move futex_queue() into futex_wait_setup()] Sebastian Andrzej Siewior
2025-02-26 8:15 ` Thomas Gleixner
2025-02-26 8:40 ` Sebastian Andrzej Siewior
2025-02-25 17:09 ` [PATCH v9 02/11] futex: Create helper function to initialize a hash slot Sebastian Andrzej Siewior
2025-02-25 17:09 ` [PATCH v9 03/11] futex: Add basic infrastructure for local task local hash Sebastian Andrzej Siewior
2025-02-25 17:09 ` [PATCH v9 04/11] futex: Hash only the address for private futexes Sebastian Andrzej Siewior
2025-02-25 17:09 ` [PATCH v9 05/11] futex: Allow automatic allocation of process wide futex hash Sebastian Andrzej Siewior
2025-02-25 17:09 ` [PATCH v9 06/11] futex: Decrease the waiter count before the unlock operation Sebastian Andrzej Siewior
2025-02-25 17:09 ` [PATCH v9 07/11] futex: Introduce futex_q_lockptr_lock() Sebastian Andrzej Siewior
2025-02-25 17:09 ` [PATCH v9 08/11] futex: Acquire a hash reference in futex_wait_multiple_setup() Sebastian Andrzej Siewior
2025-02-25 17:09 ` [PATCH v9 09/11] futex: Allow to re-allocate the private local hash Sebastian Andrzej Siewior
2025-02-25 17:09 ` [PATCH v9 10/11] futex: Resize local futex hash table based on number of threads Sebastian Andrzej Siewior
2025-02-25 17:09 ` [PATCH v9 11/11] futex: Use a hashmask instead of hashsize Sebastian Andrzej Siewior
2025-02-26 8:17 ` Thomas Gleixner [this message]
2025-03-03 10:54 ` [PATCH v9 00/11] futex: Add support task local hash maps Peter Zijlstra
2025-03-03 14:17 ` Sebastian Andrzej Siewior
2025-03-03 16:40 ` Sebastian Andrzej Siewior
2025-03-04 14:58 ` Sebastian Andrzej Siewior
2025-03-05 9:02 ` Sebastian Andrzej Siewior
2025-03-10 16:01 ` Peter Zijlstra
2025-03-10 16:27 ` Sebastian Andrzej Siewior
2025-03-11 10:17 ` Peter Zijlstra
2025-03-11 10:33 ` Sebastian Andrzej Siewior
2025-03-10 15:57 ` Peter Zijlstra
2025-03-11 15:20 ` Sebastian Andrzej Siewior
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