linux-kernel - Re: futex performance regression from "futex: Allow automatic allocation of process wide futex hash"

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250626135034.18sab4Xp@linutronix.de>
Date: Thu, 26 Jun 2025 15:50:34 +0200
From: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To: Peter Zijlstra <peterz@...radead.org>
Cc: Chris Mason <clm@...a.com>, linux-kernel@...r.kernel.org,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: futex performance regression from "futex: Allow automatic
 allocation of process wide futex hash"

On 2025-06-26 15:17:15 [+0200], Peter Zijlstra wrote:
> > I'd vote for defaulting to global for one more release.
> 
> Probably best to do that; means we don't have to rush crazy code :-)

If we do that, that means we need to ensure that the private hash is not
deployed while a thread is created and the prctl() function can only
work create the private hash if the application is single threaded.

Sebastian