I notice you are using -rt kernel. Do you actually need realtime features?
Yes, I actually need the realtime feature. I have one task which needs to run periodically in realtime (triggered every 10ms by an external IRQ).
How fast response do you need to the external IRQ?
Can you try to reproduce the problem on 4.19.193?
This is only a problem with the realtime patch. The patch introduces migrate_enable which is part of the callstack:
Jun 1 09:11:46 sicam kernel: [46802.944165] BUG: using smp_processor_id() in preemptible [00000000] code: TCPTSK/1809 Jun 1 09:11:46 sicam kernel: [46802.944210] caller is migrate_enable+0x40/0x488
Fun :-(. As Jan mentioned, testing if it can be reproduced with 4.19.193-rt81 would be useful.
Best regards, Pavel
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