Re: Timer Selection

From: Andi Kleen
Date: Sun Sep 10 2006 - 09:36:10 EST


On Sunday 10 September 2006 12:34, Dong Feng wrote:
> In i386 architecture, there are five timers as candidates in the selection
> of "cur_timer." I feel among the five only two types can be used as Kernel
> base timer, HPET and PIT. Kernel base timer is the timer trigger
> timer_interrupt() periodically. Namely, the timer installed on IRQ 0 in
> i386 architecture.
>
> Is the above understanding correct? Particularly I want to confirm which
> timers can be used as Kernel base timer.

Only HPET and PIT can be interrupt 0 in the PC architecture
(HPET only if the legacy option is available), but there is no reason
the main timer handler cannot be driven from another interval timer (e.g.
x86-64 offers the APIC timer as a option for this)

-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/