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Date:   Fri, 12 Jun 2020 15:09:52 +0200
From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     zanussi@kernel.org
Cc:     LKML <linux-kernel@vger.kernel.org>,
        linux-rt-users <linux-rt-users@vger.kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Carsten Emde <C.Emde@osadl.org>,
        John Kacur <jkacur@redhat.com>, Daniel Wagner <wagi@monom.org>,
        Clark Williams <williams@redhat.com>,
        Pavel Machek <pavel@denx.de>
Subject: Re: [PATCH RT 3/4] tasklet: Fix UP case for tasklet CHAINED state
Message-ID: <20200612130952.wzyzebdc2wxahxkh@linutronix.de>
References: <cover.1591898986.git.zanussi@kernel.org>
 <2262ed0571ef9c2f24752189b55c965ce9c16d2f.1591898986.git.zanussi@kernel.org>
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On 2020-06-11 13:10:16 [-0500], zanussi@kernel.org wrote:
> commit 62d0a2a30cd0 (tasklet: Address a race resulting in
> double-enqueue) addresses a problem that can result in a tasklet being
> enqueued on two cpus at the same time by combining the RUN flag with a
> new CHAINED flag, and relies on the combination to be present in order
> to zero it out, which can never happen on (!SMP and !PREEMPT_RT_FULL)
> because the RUN flag is SMP/PREEMPT_RT_FULL-only.
> 
> So make sure the above commit is only applied for the SMP ||
> PREEMPT_RT_FULL case.
> 
> Fixes: 62d0a2a30cd0 ("tasklet: Address a race resulting in double-enqueue")
> Signed-off-by: Tom Zanussi <zanussi@kernel.org>
> Reported-by: Ramon Fried <rfried.dev@gmail.com>
> Tested-By: Ramon Fried <rfried.dev@gmail.com>

Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

Sebastian