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From: Nam Cao <namcao@linutronix.de>
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To: Christian Brauner <brauner@kernel.org>
Cc: Soheil Hassas Yeganeh <soheil@google.com>, Alexander Viro
 <viro@zeniv.linux.org.uk>, Jan Kara <jack@suse.cz>, Shuah Khan
 <shuah@kernel.org>, Davidlohr Bueso <dave@stgolabs.net>, Khazhismel
 Kumykov <khazhy@google.com>, Willem de Bruijn <willemb@google.com>, Eric
 Dumazet <edumazet@google.com>, Jens Axboe <axboe@kernel.dk>,
 linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-kselftest@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 2/2] eventpoll: Fix epoll_wait() report false negative
In-Reply-To: <20260429-november-speisen-3084d769d316@brauner>
References: <cover.1752824628.git.namcao@linutronix.de>
 <43d64ad765e2c47e958f01246320359b11379466.1752824628.git.namcao@linutronix.de>
 <CACSApvZT5F4F36jLWEc5v_AbqZVQpmH1W7UK21tB9nPu=OtmBA@mail.gmail.com>
 <20250718085948.3xXGcxeQ@linutronix.de>
 <20260429-november-speisen-3084d769d316@brauner>
Date: Wed, 29 Apr 2026 09:27:59 +0200
Message-ID: <87340exm2o.fsf@yellow.woof>
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Christian Brauner <brauner@kernel.org> writes:
> The selftests rely on this behavior that timeout=0 sees events from a
> concurrently running producer. They would fail at a very higher rate
> after this change - believe me I had a similar patch that changed
> something in this area.

Huh, that's interesting. Do you still remember which selftest cases rely
on this behavior? I would like to study them further.

> I would explore the seqcount that Mateusz suggested tbh.

I will investigate that.

Nam