Re: Linux 2.6.21-rc1

Daniel Walker
2007-02-21T20:03:04Z

On Wed, 2007-02-21 at 20:23 +0100, Thomas Gleixner wrote:
> On Wed, 2007-02-21 at 10:23 -0800, Daniel Walker wrote:
> > Right, but eventually there isn't a regular timer interrupt through the
> > io-apic. I don't think in the past IRQ0 stops without the system
> > crashing, so check_timer() could assume the timer (IRQ0) is _always_
> > regular.
> >
> > do you know what the requirement are for routing the NMI through the
> > io-apic?
>
> Sorry. I checked. switching PIT off really breaks nmi_watchdog=1, as
> this just mirrors IRQ#0 to the NMI. No IRQ#0 from PIT, no NMI
>
> We could keep PIT running with an empty interrupt handler when
> nmi_watchdog=1 is set, but this interferes nicely with broadcasting.
>
> Does nmi_watchdog=2 work ? We might switch to that, when a local APIC is
> available.
>
> tglx
>
>

There's a compile failure during my bisect.

distcc[3863] ERROR: compile /tmp//hrtimer.tmp.dwalker1.3795.i on dwalker3/120 failed
kernel/hrtimer.c: In function 'hrtimer_cpu_notify':
kernel/hrtimer.c:884: warning: implicit declaration of function 'clockevents_notify'
kernel/hrtimer.c:884: error: 'CLOCK_EVT_NOTIFY_CPU_DEAD' undeclared (first use in this function)
kernel/hrtimer.c:884: error: (Each undeclared identifier is reported only once
kernel/hrtimer.c:884: error: for each function it appears in.)
drivers/ide/setup-pci.c: In function 'ide_scan_pcibus':
drivers/ide/setup-pci.c:866: warning: ignoring return value of '__pci_register_driver', declared with attribute warn_unused_result
make[1]: *** [kernel/hrtimer.o] Error 1

from this commit,

commit f8381cba04ba8173fd5a2b8e5cd8b3290ee13a98
Author: Thomas Gleixner <tglx@linutronix.de>
Date: Fri Feb 16 01:28:02 2007 -0800

[PATCH] tick-management: broadcast functionality

With Ingo Molnar <mingo@elte.hu>

Add broadcast functionality, so per cpu clock event devices can be registere
as dummy devices or switched from/to broadcast on demand. The broadcast
function distributes the events via the broadcast function of the clock even
device. This is primarily designed to replace the switch apic timer to / fr
IPI in power states, where the apic stops.