i'm not an xmon expert, but maybe it might make more sense to first
disable preemption, then interrupts - otherwise you could be preempted
right after having disabled these interrupts (and be scheduled to
another CPU, etc.). What is the difference between local_irq_save() and
the above 'disable interrupts' sequence? If it's not the same and
xmon_core() relied on having hardirqs disabled then it might make sense
to do a local_irq_save() there, instead of a preempt_disable().
Ingo
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