Re: Livelock on recent current

On Fri, Sep 11, 2020 at 1:01 AM <driesm.michiels_at_gmail.com> wrote:

> > > On 09.09.20 06:18, Kevin Oberman wrote:
> > > > I am seeing a problem since I moved to current on my laptop this
> week.
> > > > It's odd as it is linked to the keyboard. As long as the keyboard is
> > > > active, everything is fine, but if the keyboard is not used, after a
> > > > few minutes, it locks up and gets very hot. The system may be busy
> > > > or idle. The system seems completely locked. It does not respond in
> > > > the network and the display, X or just vt is frozen. The only factor
> > > > is use
> > of the
> > > keyboard.
> >
> > I'm actually very happy someone else ran into this too! I have a Lenovo
> T490
> > (azerty edition, yeah I known ...) I found it incredible hard to
> describe,
> but i
> > have the exact same problem.
> > I categorized it as "random system freezes", but now that you say its
> related to
> > keyboard interaction it makes sense when I observe the lock.
> >
> > System locks up when it happens and the fan ramps up AFTER the dead lock.
> > I'm pretty sure the getting "hot" symptom is caused by the deadlock and
> not a
> > symptom of the deadlock.
>
> Maybe a very important factor, the issue is not present in STABLE-12, I
> downgraded previous week to verify this.
>
> >
> > >
> > > Reminds me of this bug:
> > >
> > > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=225341
> >
> > I am also using a non default keyboard layout, as described in the bug
> above.
> > I'll probably try the patch in the coming weekend to see if it helps.
> >
> > >
> > > I've been experiencing similar hangs when that timer in atkbd is
> enabled.
> > It
> > > doesn't seem to happen in the default keyboard configuration, though.
> > >
> > > -Jan


I'm happy to see that I am not crazy!

This is mostly anecdotal. The freezes have occurred regularly, without
question, but the details are not statistically verified. This is based on
my perceptions. The only things I am really sure of is that the system is
unusable on head and runs well on 12.1-Release. This system has a rather
new Intel GPU, the Comet Lake, and is only supported on head with
drm-devel-kmod, so moving back to 12.1 is not an option. I am curious what
processor is on the T490. I am using the default keyboard layout.
On terminal sessions (vt), when the keyboard is idle. I have had the system
run for a couple of hours or longer with no problems. To get bigger ports
to build, I usually switch to another vty and keep that one fairly busy. It
will freeze when no vty is active, but as long as any is active every
minute or less. I have had freezes in under a minute, but rarely.

Moving on to other possibly related (or not) issues:
When running on X (MATE), it may freeze whether the keyboard is active or
not. OTOH, it seems to freeze less often. I've had X lock up mid-word but
also run for 15 or more minutes. It eventually does freeze, but I don't
think I've ever gone more than 10 minutes on an idle keyboard without a
freeze without X running.

Switching to a vty and keeping it fairly active still seems to keep the
system alive while X is being used. X is performing very poorly. If the
processors are busy, say by building a port, screen updates are very slow,
often pausing for several seconds. Expose events seem to often redraw all
windows which is very annoying. Several times I thought the system was
frozen only to suddenly have the screen update and everything be normal,
again.
--
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman_at_gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683