From: Peter Zijlstra <peterz@infradead.org>
To: Juri Lelli <juri.lelli@redhat.com>
Cc: "Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Darren Hart" <dvhart@infradead.org>,
"Davidlohr Bueso" <dave@stgolabs.net>,
"André Almeida" <andrealmeid@igalia.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-rt-users <linux-rt-users@vger.kernel.org>,
"Valentin Schneider" <vschneid@redhat.com>,
"Waiman Long" <longman@redhat.com>,
"Sebastian Andrzej Siewior" <bigeasy@linutronix.de>
Subject: Re: Futex hash_bucket lock can break isolation and cause priority inversion on RT
Date: Tue, 8 Oct 2024 19:38:59 +0200 [thread overview]
Message-ID: <20241008173859.GE17263@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <ZwVOMgBMxrw7BU9A@jlelli-thinkpadt14gen4.remote.csb>
On Tue, Oct 08, 2024 at 04:22:26PM +0100, Juri Lelli wrote:
> Does this report make any sense? If it does, has this issue ever been
> reported and possibly discussed? I guess it’s kind of a corner case, but
> I wonder if anybody has suggestions already on how to possibly try to
> tackle it from a kernel perspective.
Any shared lock can cause such havoc. Futex hash buckets is just one of
a number of very popular ones that's relatively easy to hit.
I do have some futex-numa patches still pending, but they won't
magically sure this either. Userspace needs help at the very least.
next prev parent reply other threads:[~2024-10-08 17:39 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-08 15:22 Futex hash_bucket lock can break isolation and cause priority inversion on RT Juri Lelli
2024-10-08 15:38 ` André Almeida
2024-10-08 15:51 ` Sebastian Andrzej Siewior
2024-10-08 15:59 ` André Almeida
2024-10-08 18:09 ` Sebastian Andrzej Siewior
2024-10-09 8:36 ` Juri Lelli
2024-10-24 22:36 ` Thomas Gleixner
2024-10-08 17:38 ` Peter Zijlstra [this message]
2024-10-08 19:44 ` Waiman Long
2024-10-09 7:22 ` Peter Zijlstra
2024-10-09 8:26 ` Juri Lelli
2024-10-08 18:30 ` Waiman Long
2024-10-09 8:28 ` Juri Lelli
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20241008173859.GE17263@noisy.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=andrealmeid@igalia.com \
--cc=bigeasy@linutronix.de \
--cc=dave@stgolabs.net \
--cc=dvhart@infradead.org \
--cc=juri.lelli@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
--cc=longman@redhat.com \
--cc=mingo@redhat.com \
--cc=tglx@linutronix.de \
--cc=vschneid@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox