DragonFly BSD
DragonFly users List (threaded) for 2006-06
[Date Prev][Date Next]  [Thread Prev][Thread Next]  [Date Index][Thread Index]

Re: cpu0 and interrupts


From: Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>
Date: Tue, 20 Jun 2006 09:04:00 -0700 (PDT)

:I see something about before that all interrupts run on
:cpu0 but I don't understand completely. If you have
:software interrupt in driver (a timer) does that also
:always run on cpu0? So there is no chance to separate timer
:processing?
:
:Dimitri

    The kernel SYSTIMER abstraction is per-cpu, but the current implementation
    uses the 8254 timer so the actual hardware interrupt goes to just one
    cpu.  IPI messaging is used to forward it to the correct cpu.

    On systems with APICs, there is a local apic timer for each cpu.  It
    would not be too hard to make the SYSTIMER abstraction use that timer
    to get per-cpu timer interrupts.

					-Matt
					Matthew Dillon 
					<dillon@xxxxxxxxxxxxx>



[Date Prev][Date Next]  [Thread Prev][Thread Next]  [Date Index][Thread Index]