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Date:   Fri, 2 Jun 2023 13:18:37 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc:     linux-kernel@vger.kernel.org, Ben Segall <bsegall@google.com>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
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        Thomas Gleixner <tglx@linutronix.de>,
        Valentin Schneider <vschneid@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>
Subject: Re: [PATCH] sched: Consider task_struct::saved_state in
 wait_task_inactive().
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On Fri, Jun 02, 2023 at 12:49:58PM +0200, Sebastian Andrzej Siewior wrote:
> On 2023-06-02 12:37:31 [+0200], Peter Zijlstra wrote:
> > ---
> > Subject: sched: Unconditionally use full-fat wait_task_inactive()
> > From: Peter Zijlstra <peterz@infradead.org>
> > Date: Fri Jun  2 10:42:53 CEST 2023
> > 
> > While modifying wait_task_inactive() for PREEMPT_RT; the build robot
> > noted that UP got broken. This led to audit and consideration of the
> > UP implementation of wait_task_inactive().
> > 
> > It looks like the UP implementation is also broken for PREEMPT;
> 
> If UP is broken for PREEMPT, shouldn't it get a fixes or stable tag?

It has been broken *forever*, I don't think we need to 'rush' a fix.
Also, I don't think anybody actually uses a UP+PREEMPT kernel much, but
what do I know.