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For what are IPIs (Inter-Processor-Interrupts) used?

Posted: Wed Feb 10, 2010 10:15 am
by ErikVikinger
Hello,


For what are IPIs used? (general on UMA-SMP-Architectures and special on x86-based Architectures)
Only for flushing remote TLBs?


Thanks for Answers!
Erik

Re: For what are IPIs (Inter-Processor-Interrupts) used?

Posted: Wed Feb 10, 2010 10:20 am
by XanClic
As for me, I also use them to force a processor to schedule (because I don't use the LAPIC timer yet) and to shut all CPUs down in case of a BSOD (though it's actually an orange screen of death in my OS).

Re: For what are IPIs (Inter-Processor-Interrupts) used?

Posted: Wed Feb 10, 2010 12:50 pm
by ErikVikinger
Hallo,

XanClic wrote:I also use them to force a processor to schedule (because I don't use the LAPIC timer yet)
You mean you forward the Timer-IRQ from the BSP (if it be the IRQ-Receiver-Processor) to an other Processor?
XanClic wrote:to shut all CPUs down in case of a BSOD (though it's actually an orange screen of death in my OS).
Okay, it is a new reason for IPI for me.

Exist any other reasons for IPI?


Regards
Erik

Re: For what are IPIs (Inter-Processor-Interrupts) used?

Posted: Wed Feb 10, 2010 1:34 pm
by XanClic
ErikVikinger wrote:You mean you forward the Timer-IRQ from the BSP (if it be the IRQ-Receiver-Processor) to an other Processor?
Yes, exactly that. I know, it's very slow, but because I don't have another timer for now and I also don't initialize the I/O-APIC yet (which could be used to forward the IRQ to the other processors, afaik), it is necessary.

Re: For what are IPIs (Inter-Processor-Interrupts) used?

Posted: Thu Feb 11, 2010 1:15 pm
by ErikVikinger
Hello,

XanClic wrote:Yes, exactly that. ...
Okay, thanks for your answer.


@all:
Anything else?
Any other use for IPIs?


Regards
Erik