* Timer Selection
[not found] <a2ebde260609100334v65bf5e4fx754e3b00576bfb9f@mail.gmail.com>
@ 2006-09-10 10:37 ` Dong Feng
2006-09-10 13:51 ` Andi Kleen
1 sibling, 0 replies; 3+ messages in thread
From: Dong Feng @ 2006-09-10 10:37 UTC (permalink / raw)
To: linux-kernel
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.
Thanks.
Feng,Dong
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Timer Selection
[not found] <a2ebde260609100334v65bf5e4fx754e3b00576bfb9f@mail.gmail.com>
2006-09-10 10:37 ` Timer Selection Dong Feng
@ 2006-09-10 13:51 ` Andi Kleen
2006-09-10 14:23 ` Dong Feng
1 sibling, 1 reply; 3+ messages in thread
From: Andi Kleen @ 2006-09-10 13:51 UTC (permalink / raw)
To: Dong Feng; +Cc: Jeremy Fitzhardinge, linux-kernel
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
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Timer Selection
2006-09-10 13:51 ` Andi Kleen
@ 2006-09-10 14:23 ` Dong Feng
0 siblings, 0 replies; 3+ messages in thread
From: Dong Feng @ 2006-09-10 14:23 UTC (permalink / raw)
To: Andi Kleen; +Cc: Jeremy Fitzhardinge, linux-kernel
Thank you very much.
2006/9/10, Andi Kleen <ak@suse.de>:
> 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
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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[not found] <a2ebde260609100334v65bf5e4fx754e3b00576bfb9f@mail.gmail.com>
2006-09-10 10:37 ` Timer Selection Dong Feng
2006-09-10 13:51 ` Andi Kleen
2006-09-10 14:23 ` Dong Feng
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