This morning while running Zoom, I got a weird crash of the kernel(?) or
something. The desktop and zoom window were there. sound was coming out
of the speakers, but it was in a loop. Ie, it was about 1-2 sec of sound
of sound and of video of the zoom were coming out but just looping.
There was no mouse cursor, and the keyboard was unresponsive. When
finally hit the big red switch, the system rebooted to a blank screen.
It only unblanked when I switched off and then on again the screen (Dell
touchscreen). This is a desktop machine. While the looping was going on,
the network connection was gone, or at least I could not get any response from another computer
trying to connect.

Mageia 8 updated.

On 22.05.2021 at 16:13, William Unruh scribbled:

> This morning while running Zoom, I got a weird crash of the kernel(?)
> or something. The desktop and zoom window were there. sound was
> coming out of the speakers, but it was in a loop. Ie, it was about
> 1-2 sec of sound of sound and of video of the zoom were coming out
> but just looping. There was no mouse cursor, and the keyboard was
> unresponsive. When finally hit the big red switch, the system
> rebooted to a blank screen. It only unblanked when I switched off and
> then on again the screen (Dell touchscreen). This is a desktop
> machine. While the looping was going on, the network connection was
> gone, or at least I could not get any response from another computer
> trying to connect.
>
> Mageia 8 updated.

Proprietary Nvidia driver?

--
With respect,
= Aragorn =

On 2021-05-22, Aragorn <thorongil@telenet.be> wrote:
> On 22.05.2021 at 16:13, William Unruh scribbled:
>
>> This morning while running Zoom, I got a weird crash of the kernel(?)
>> or something. The desktop and zoom window were there. sound was
>> coming out of the speakers, but it was in a loop. Ie, it was about
>> 1-2 sec of sound of sound and of video of the zoom were coming out
>> but just looping. There was no mouse cursor, and the keyboard was
>> unresponsive. When finally hit the big red switch, the system
>> rebooted to a blank screen. It only unblanked when I switched off and
>> then on again the screen (Dell touchscreen). This is a desktop
>> machine. While the looping was going on, the network connection was
>> gone, or at least I could not get any response from another computer
>> trying to connect.
>>
>> Mageia 8 updated.
>
> Proprietary Nvidia driver?

Nope, Intel driver

inxi -AG
Graphics: Device-1: Intel CoffeeLake-S GT2 [UHD Graphics 630] driver: i915 v: kernel
Display: server: Mageia X.org 1.20.11 driver: intel,v4l resolution: 1920x1080~60Hz
OpenGL: renderer: Mesa Intel UHD Graphics 630 (CFL GT2) v: 4.6 Mesa 21.0.2
Audio: Device-1: Intel Cannon Lake PCH cAVS driver: snd_hda_intel
Device-2: Logitech Webcam C930e type: USB driver: snd-usb-audio,uvcvideo
Sound Server: ALSA v: k5.10.33-desktop-1.mga8

>

On 22.05.2021 at 16:45, William Unruh scribbled:

> On 2021-05-22, Aragorn <thorongil@telenet.be> wrote:
> > On 22.05.2021 at 16:13, William Unruh scribbled:
> >
> >> This morning while running Zoom, I got a weird crash of the
> >> kernel(?) or something. The desktop and zoom window were there.
> >> sound was coming out of the speakers, but it was in a loop. Ie, it
> >> was about 1-2 sec of sound of sound and of video of the zoom were
> >> coming out but just looping. There was no mouse cursor, and the
> >> keyboard was unresponsive. When finally hit the big red switch,
> >> the system rebooted to a blank screen. It only unblanked when I
> >> switched off and then on again the screen (Dell touchscreen). This
> >> is a desktop machine. While the looping was going on, the network
> >> connection was gone, or at least I could not get any response from
> >> another computer trying to connect.
> >>
> >> Mageia 8 updated.
> >
> > Proprietary Nvidia driver?
>
> Nope, Intel driver
>
> inxi -AG
> Graphics: Device-1: Intel CoffeeLake-S GT2 [UHD Graphics 630]
> driver: i915 v: kernel Display: server: Mageia X.org 1.20.11 driver:
> intel,v4l resolution: 1920x1080~60Hz OpenGL: renderer: Mesa Intel UHD
> Graphics 630 (CFL GT2) v: 4.6 Mesa 21.0.2 Audio: Device-1: Intel
> Cannon Lake PCH cAVS driver: snd_hda_intel Device-2: Logitech Webcam
> C930e type: USB driver: snd-usb-audio,uvcvideo Sound Server: ALSA v:
> k5.10.33-desktop-1.mga8

My educated guess would be that Zoom hit a bug in the v4l subsystem.

I've seen a similar thing happen on my previous desktop machine, which
was a refurbished box, but in that case it was a hardware issue. Its
PSU wasn't supplying enough juice anymore to the onboard GPU, which
itself was also dying.

But the looping sound was also typical there — at least, for a number
of seconds, and then it would stop because by then the system had
completely crashed and I had to hit the big red button. (Actually, it
was lit by a blue LED, with another red LED for drive activity built
into the same button, but anyway. :p)

--
With respect,
= Aragorn

On Sat, 22 May 2021 16:13:55 -0000 (UTC), William Unruh wrote:
> This morning while running Zoom,

I'll assume latest zoom installed

$ rpm -qa "zoom*"
zoom-5.6.16888.0424-1

> I got a weird crash of the kernel(?) or something.

I would suggest that you might want to enable core dump that way
you have a better chance of alt least knowing who crashed.

Snippet from my brain book
$ uh core dump
_enable_core_dump_ sysctl -w kernel.core_uses_pid=1
_enable_core_dump_ sysctl -w fs.suid_dumpable=2
_enable_core_dump_
sysctl -w kernel.core_pattern="/core/%e_%t_%s_uid%u.core"
_enable_core_dumps01_ ulimit -c unlimited
_enable_core_dumps02_ echo 1 > /proc/sys/kernel/core_uses_pid
_enable_core_dumps03_ echo "%e_%p_%s.core" > /proc/sys/kernel/core_pattern

Since I automate those kinds of changes there is this snippet
from sysctl_conf_changes:

_xx_fn=/etc/sysctl.d/xx__sysctl.conf

cat > $_xx_fn <<EOD
# enable System Request debugging functionality of the kernel
kernel.sysrq = 1

# Enabling suid dump PID appending and set core location and name

kernel.core_uses_pid = 1
kernel.core_pattern = /var/tmp/%e_%p_%s.core
fs.suid_dumpable = 2
EOD
echo "#******** end $_xx_fn *************" >> $_xx_fn
echo "Created $_xx_fn"
sysctl --system
sysctl --system --write

User login needs to set ulimit
user_home_setup: ulimit -c unlimited # The maximum size of core files

Since I run xterm, I find it handy to always check for core files
via ~/.bashrc

$ cat /local/bin/ck_4_core
#!/bin/bash
#*************************************************************
#* ck_4_core - Check for any core files
#*
#* Usually called from ~/.bashrc
#*
#*************************************************************
for _d in $HOME /tmp /var/tmp /var/lib/systemd/coredump ; do
_cnt=$(ls $_d/*core* 2> /dev/null | wc -l)
if [ $_cnt -gt 0 ] ; then
echo " "
ls -hla $_d/*core*
echo "
# from $(hostname --short) ck_4_core
# There is a $_d/*core file. To remove it, run
rm --force $_d/*core*

exit 0

"
fi
done

#*************** end ck_4_core ****************************************

On 2021-05-22, Aragorn <thorongil@telenet.be> wrote:
> On 22.05.2021 at 16:45, William Unruh scribbled:
>
>> On 2021-05-22, Aragorn <thorongil@telenet.be> wrote:
>> > On 22.05.2021 at 16:13, William Unruh scribbled:
>> >
....
>
> My educated guess would be that Zoom hit a bug in the v4l subsystem.
>
> I've seen a similar thing happen on my previous desktop machine, which
> was a refurbished box, but in that case it was a hardware issue. Its
> PSU wasn't supplying enough juice anymore to the onboard GPU, which
> itself was also dying.
>
> But the looping sound was also typical there — at least, for a number
> of seconds, and then it would stop because by then the system had
> completely crashed and I had to hit the big red button. (Actually, it
> was lit by a blue LED, with another red LED for drive activity built
> into the same button, but anyway. :p)

In my case the looping went on "forever" (well >5min.) There was no
response to any external probes on the network. There was no response to
anything I did on the keyboard. The strange thing was that when i
finally hit the switch and tried to reboot, the light on the computer
came on, but nothing showed onthe screen. I tried a couple of times, and
finally switched off the monitor and switched it back on, and suddenly
the boot process showed up on the screen (I always run my machine with
no quiet and no splash on the boot). Very strange that it managed to
switch off the screen on boot. (the screen was still showing the loop
before I switched off the computer).

It seems to be running fine now.

>

On 22/05/2021 17:13, William Unruh wrote:
> This morning while running Zoom, I got a weird crash of the kernel(?) or
> something. The desktop and zoom window were there. sound was coming out
> of the speakers, but it was in a loop. Ie, it was about 1-2 sec of sound
> of sound and of video of the zoom were coming out but just looping.
> There was no mouse cursor, and the keyboard was unresponsive. When
> finally hit the big red switch, the system rebooted to a blank screen.
> It only unblanked when I switched off and then on again the screen (Dell
> touchscreen). This is a desktop machine. While the looping was going on,
> the network connection was gone, or at least I could not get any response from another computer
> trying to connect.
>
> Mageia 8 updated.
>
That's interesting. That's happened twice to me, listening to internet
radio through Chrome, 2 seconds of looping sound. Little blue button
required. nVidia card (GE 710) and presumably nVidia driver, because I
would have answered Yes to the "proprietary driver" option during
installation. PC is less than a month old. Other problems found include
Chrome segfaulting twice, various unexplained system halts with nothing
obvious in syslog at the moment of stoppage. Eventually ran memtest, and
found problems in both my memory modules, which have now gone back to
the supplier for replacement.

--
Grimble
Registered Linux User #450547
Machine 'Bach' running Plasma 5.20.4 on 5.10.37-desktop-2.mga8 kernel.
Mageia release 8 (Official) for x86_64