Re: [PATCH v2] eventpoll: Fix priority inversion problem

To: Nam Cao <namcao@xxxxxxxxxxxxx>, Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>, Christian Brauner <brauner@xxxxxxxxxx>, Jan Kara <jack@xxxxxxx>, Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>, John Ogness <john.ogness@xxxxxxxxxxxxx>, Clark Williams <clrkwllms@xxxxxxxxxx>, Steven Rostedt <rostedt@xxxxxxxxxxx>, linux-fsdevel@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, linux-rt-devel@xxxxxxxxxxxxxxx, linux-rt-users@xxxxxxxxxxxxxxx, Joe Damato <jdamato@xxxxxxxxxx>, Martin Karsten <mkarsten@xxxxxxxxxxxx>, Jens Axboe <axboe@xxxxxxxxx>
Subject: Re: [PATCH v2] eventpoll: Fix priority inversion problem
From: Holger Hoffstätte <holger@xxxxxxxxxxxxxxxxxxxxxx>
Date: Wed, 28 May 2025 08:07:33 +0200
Cc: Frederic Weisbecker <frederic@xxxxxxxxxx>, Valentin Schneider <vschneid@xxxxxxxxxx>
In-reply-to: <3475f3f1-4109-b6ac-6ea6-dadcdec8db1f@applied-asynchrony.com>
Organization: Applied Asynchrony, Inc.
References: <20250523061104.3490066-1-namcao@linutronix.de> <3475f3f1-4109-b6ac-6ea6-dadcdec8db1f@applied-asynchrony.com>

On 2025-05-28 07:57, Holger Hoffstätte wrote:

It seems the condition (!n) in __ep_remove is not always true and the WARN_ON triggers.


This should of course read "not always false", sorry.

-h

References:
- [PATCH v2] eventpoll: Fix priority inversion problem
  - From: Nam Cao
- Re: [PATCH v2] eventpoll: Fix priority inversion problem
  - From: Holger Hoffstätte