Re: [PATCH] sched: Consider task_struct::saved_state in wait_task_inactive().

[Peter Zijlstra]

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@xxxxxxxxxxxxx>
> > 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.