From: Breno Leitao <leitao@debian.org>
To: linux-kernel@vger.kernel.org
Cc: linux-tip-commits@vger.kernel.org,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Thomas Gleixner <tglx@kernel.org>,
x86@kernel.org
Subject: Re: [tip: locking/core] futex: Optimize futex hash bucket access patterns
Date: Fri, 12 Jun 2026 01:13:59 -0700 [thread overview]
Message-ID: <aiu_cJlyshUEWDgK@gmail.com> (raw)
In-Reply-To: <178124827005.1393914.7048476948730678912.tip-bot2@tip-bot2>
On Fri, Jun 12, 2026 at 07:11:10AM +0000, tip-bot2 for Peter Zijlstra wrote:
> futex: Optimize futex hash bucket access patterns
>
> Breno reported significant c2c HITM in a futex hash heavy workload.
...
> Funnily this turns out to remove more code than it adds and significantly
> improves futex hash performance (as measured by 'perf bench futex hash'):
Fascinating!
> Reported-by: Breno Leitao <leitao@debian.org>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Tested-by: Breno Leitao <leitao@debian.org>
> Tested-by: Thomas Gleixner <tglx@kernel.org>
> Link: https://patch.msgid.link/20260610135510.GB1430057@noisy.programming.kicks-ass.net
Thanks so much Peter!
--breno
next prev parent reply other threads:[~2026-06-12 8:14 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-05 16:53 [PATCH RFC] futex: avoid false sharing between hb->chain and the bucket lock Breno Leitao
2026-06-09 10:46 ` Peter Zijlstra
2026-06-09 15:28 ` Breno Leitao
2026-06-09 20:11 ` Peter Zijlstra
2026-06-09 20:18 ` Peter Zijlstra
2026-06-10 11:22 ` Thomas Gleixner
2026-06-10 11:25 ` Peter Zijlstra
2026-06-10 13:55 ` Peter Zijlstra
2026-06-12 7:11 ` [tip: locking/core] futex: Optimize futex hash bucket access patterns tip-bot2 for Peter Zijlstra
2026-06-12 8:13 ` Breno Leitao [this message]
2026-06-10 13:56 ` [PATCH RFC] futex: avoid false sharing between hb->chain and the bucket lock Breno Leitao
2026-06-09 20:16 ` Thomas Gleixner
2026-06-09 20:23 ` Peter Zijlstra
2026-06-09 20:25 ` Peter Zijlstra
2026-06-09 20:32 ` Thomas Gleixner
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