From: Nam Cao <namcao@linutronix.de>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
John Ogness <john.ogness@linutronix.de>,
Clark Williams <clrkwllms@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-rt-devel@lists.linux.dev, linux-rt-users@vger.kernel.org,
Joe Damato <jdamato@fastly.com>,
Martin Karsten <mkarsten@uwaterloo.ca>,
Jens Axboe <axboe@kernel.dk>,
Frederic Weisbecker <frederic@kernel.org>,
Valentin Schneider <vschneid@redhat.com>
Subject: Re: [PATCH v3] eventpoll: Fix priority inversion problem
Date: Wed, 25 Jun 2025 18:02:27 +0200 [thread overview]
Message-ID: <20250625160227.B9-NAdc2@linutronix.de> (raw)
In-Reply-To: <20250625155713.lckVkmJH@linutronix.de>
On Wed, Jun 25, 2025 at 05:57:18PM +0200, Nam Cao wrote:
> On Wed, Jun 25, 2025 at 05:33:54PM +0200, Sebastian Andrzej Siewior wrote:
> > On 2025-06-25 17:27:02 [+0200], Nam Cao wrote:
> > > To be sure, I tried your suggestion. Systemd sometimes failed to boot, and
> > > my stress test crashed instantly.
> >
> > I had a trace_printk() there while testing and it never triggered.
>
> This code path is only executed for broken userspace.
Forgot to mention, my test crashed because the __llist_add(n, &txlist)
below doesn't care if 'n' is already in a list. By changing to from
llist_del_first() to llist_del_first_init(), it is possible for 'n' to be
in a list, therefore __llist_add() would break.
Nam
next prev parent reply other threads:[~2025-06-25 16:02 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-27 9:08 [PATCH v3] eventpoll: Fix priority inversion problem Nam Cao
2025-05-30 5:08 ` Christian Brauner
2025-06-25 15:35 ` Sebastian Andrzej Siewior
2025-06-26 13:35 ` Frederic Weisbecker
2025-06-26 13:51 ` Sebastian Andrzej Siewior
2025-06-25 14:50 ` Sebastian Andrzej Siewior
2025-06-25 15:27 ` Nam Cao
2025-06-25 15:33 ` Sebastian Andrzej Siewior
2025-06-25 15:57 ` Nam Cao
2025-06-25 16:02 ` Nam Cao [this message]
2025-06-26 15:23 ` John Ogness
2025-06-26 15:49 ` Sebastian Andrzej Siewior
2025-06-26 15:56 ` Nam Cao
2025-06-30 15:08 ` K Prateek Nayak
2025-07-01 20:33 ` Florian Bezdeka
2025-07-01 12:03 ` Christian Brauner
2025-07-10 3:08 ` Xi Ruoyao
2025-07-10 3:48 ` Nam Cao
2025-07-10 4:06 ` Nam Cao
2025-07-10 4:10 ` Xi Ruoyao
2025-07-10 6:21 ` Nam Cao
2025-07-10 6:54 ` Xi Ruoyao
2025-07-10 8:32 ` Nam Cao
2025-07-10 9:47 ` Xi Ruoyao
2025-07-11 5:02 ` Nam Cao
2025-07-11 9:44 ` Christian Brauner
2025-07-11 9:48 ` Xi Ruoyao
2025-07-11 9:58 ` Nam Cao
2025-07-11 12:09 ` Xi Ruoyao
2025-07-11 12:21 ` Nam Cao
2025-07-12 0:09 ` Nam Cao
2025-07-12 8:54 ` Xi Ruoyao
2025-07-11 9:50 ` Nam Cao
2025-07-14 8:59 ` Christian Brauner
2025-07-14 10:14 ` Nam Cao
2025-07-15 9:37 ` Yann Ylavic
2025-07-15 10:08 ` Nam Cao
2025-07-14 16:16 ` Linus Torvalds
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