Re: [PREEMPT_RT] 8250 IRQ lockup when flooding serial console (was Re: [ANNOUNCE] v5.4.28-rt19)

[Steven Rostedt]

On Thu, 23 Apr 2020 12:45:59 +0200
Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote:

> On 2020-04-23 11:12:59 [+0200], Jiri Kosina wrote:
> > On Thu, 23 Apr 2020, Jiri Kosina wrote:
> >   
> > > > I'm pleased to announce the v5.4.28-rt19 patch set.   
> > > 
> > > First, I don't believe this is necessarily a regression coming with this 
> > > particular version, but this is the first kernel where I tried this and it 
> > > crashed.  
> > 
> > I just tried with 5.6.4-rt3, and I can make it explode exactly the same 
> > way:  
> 
> I though I dealt with it. In the past it triggered also with threadirqs
> on !RT but this isn't the case anymore. It still explodes on RT. Let me
> lookâ

Good, something to look for as a backport ;-)

BTW, I haven't released a new 5.4-rt because the default one is triggering
a large latency somewhere, and makes my tests fail. I'm trying to dig into
the cause when I get time.

-- Steve