Re: IO-APIC on nforce2 [PATCH] + [PATCH] for nmi_debug=1 + [PATCH]for idle=C1halt, 2.6.5

From: Prakash K. Cheemplavam
Date: Fri Apr 23 2004 - 03:50:02 EST

Len Brown wrote:
On Thu, 2004-04-22 at 13:21, Len Brown wrote:

As for your patch, I get a fast timer, and gain about 1 sec per 5 minutes.
The only patch that seemed to work without a fast timer so far was the one removed by Linus in a testing version. The AN35N has the timer override bug.

Hmm, I didn't notice fast time on my FN41, i'll look for it.

I'm not familiar with the "one removed by Linux in a testing version",
perhaps you could point me to that?

date seems to gain 9sec/hour on my Shuttle/SN41G2/FN41 when using IOAPIC

Do you get lock-ups wihtout the timer_ack/C1halt patch? If yes, this may be the cause. I remember someone finding out that Ross' patch made the timer actually slower which resulted in stable operation. Maciej found out, not connecting the timer at all made it stabke as well. So is there a possibility to sync both timers?

According to a recent post, builöding kernel with SMP makes it stable, as well, but I haven't tested.

booted with "noapic" for XT-PIC timer, it stays locked
onto my wristwatch after an hour. If the workaround is disabled,
and XT-PIC timer is used, it matches the "noapic" behaviour -- no drift.

I can't explain it. I think it is a timer problem independent of the
IRQ routing.


ps. when i ran in XT-PIC mode there were lots of ERR's registered in
/proc/interrupts -- doesn't look healthy.

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