Hi Everyone, I have been spending too much time reading IA32 System Programming Guide:
http://www.intel.com/design/pentium4/manuals/245472.htm in particular section 8.8.5. I believe that kdb may be doing interrupt acknowledge writes to the EOI register which are not needed. It is using NMI delivery, and section 8.8.5 says that the EOI write should not be done for NMI interrupts. I have never seen any problems, but it seems that kdb could be acknowledging random interrupts which don't belong to it. I tried taking the ack_APIC_irq() out of do_ack_apic_irq(), and kdb works correctly. Jim Houston - Concurrent Computer Corp.
