Re: [PATCH] Option to disable AMD C1E (allows dynticks to work)

Richard Harman
2007-12-30T21:37:16Z

Eduard-Gabriel Munteanu wrote:
> On Sun, 30 Dec 2007 15:57:59 -0500
> Richard Harman <richard@richardharman.com> wrote:
>
>> I think I may have a monkey wrench to throw into this, I finally got
>> around to testing the C1E patch, and the port80 patch. End result:
>> port80 patch has zero effect on this laptop, and the C1E patch makes
>> it stable.
>>
>> AMD C1E patch 'force_amd_c1e' (disabling the workaround):
>>
>> hpet0: at MMIO 0xfed00000, IRQs 2, 8, 31
>> hpet0: 3 32-bit timers, 25000000 Hz
>> Time: hpet clocksource has been installed.
>> Clockevents: could not switch to one-shot mode: lapic is not
>> functional. Could not switch to high resolution mode on CPU 0
>> Clockevents: could not switch to one-shot mode: lapic is not
>> functional. Could not switch to high resolution mode on CPU 1
>>
>> And with the C1E workaround enabled, the kernel doesn't whine that
>> the lapic isn't functional.
>>
>> Those were the kernel messages I was trying to paste in my earlier
>> message, saying that the lapic works. Do I have a DV6000 laptop that
>> is a strange beast all in itself?
>
> These two patches are not related in any way, they address two
> different problems. My patch enables dynticks (and those messages don't
> show up anymore), but it doesn't prevent your computer from locking up
> as you said before.
>

The C1E patch, which permits the lapic to function *does* make my system
stable. My previous method of testing (using USB peripherals) and
checking /proc/interrupts for ERRor interrupts so far hasn't caused the
system to lock up.