system lock up with RT kernel on amd64

[Colin Ian King]

Ubuntu Noble, Real Time kernel:

cking@noble-amd64-efi:~$ uname -a
Linux noble-amd64-efi 6.8.1-1002-realtime #2-Ubuntu SMP PREEMPT_RT Tue May 21 21:13:36 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

How to reproduce issue:

git clone https://github.com/ColinIanKing/stress-ng
cd stress-ng
make clean; make -j 8

sudo ./stress-ng --sched fifo --cpu -1 -t 5 --timestamp --tz --syslog --perf --no-rand-seed --times --metrics --status 5
stress-ng: 13:22:12.44 info: [1520] sched: priority not given (or set to -1), defaulting to 49
stress-ng: 13:22:12.44 info: [1520] setting to a 5 secs run per stressor
stress-ng: 13:22:12.47 info: [1520] dispatching hogs: 8 cpu
[ system becomes unresponsive ]

When the system becomes unresponsive one cannot ping the system, change console screens or interact with the console. System seems to be totally unresponsive.