Hi, I'm seeing a kernel freeze (and systemd reboots after few seconds) when docker running kubernetes with debian 4.9 RT kernel (4.9.0-6-rt-amd64). This was tested with 4.14 -rt kernel and the issue was still seen. kdump is not capturing the coredump in this case so I'm unable to check the crash logs. The system crash logs are not available in /sys/fs/pstore. When manual crash is triggered with sysrq the kdump captures the crash logs. But this does not work always. Sometimes the system does not reboot when manual crash (sysrq) is triggered and a freeze happens. Maybe the capture kernel itself hangs while taking coredump. When manual crash is triggered with sysrq the crash logs are available in /sys/fs/pstore. I'm able to reproduce a similar freeze/reset issue with the steps mentioned here https://github.com/moby/moby/issues/19758. Run "for f in $(seq 1 1000);do docker run -it --rm ubuntu echo $f; done" concurrently in 3 terminals. But I'm unable to confirm if both these issues are related due to unavailability of crash logs. Enabled CPUAccounting/MemoryAccounting in docker.service but the system freeze was still seen., sudo systemctl set-property docker.service MemoryAccounting=yes sudo systemctl set-property docker.service CPUAccounting=yes I was thinking to enable CONFIG_RT_GROUP_SCHED (allocate real CPU bandwidth to task groups). But this is disabled if PREEMPT_RT_FULL is enabled. I'm unable to root cause the reason for freeze/crash because crash logs are not available. Is there any other way to capture the crashdump? Any pointers will be helpful. Thanks. Regards, Vignesh
