Re: [PATCH] perfctr: don't use CCCR_OVF_PMI1 on Pentium 4Ds

From: Aristeu Rozanski
Date: Fri Aug 15 2008 - 08:16:42 EST


Hi Ingo,
> > Currently, setup_p4_watchdog() use CCCR_OVF_PMI1 to enable the counter
> > overflow interrupts to the second logical core. But this bit doesn't
> > work on Pentium 4 Ds (model 4, stepping 4) and this patch avoids its
> > use on these processors. [...]
>
> btw., what was the effect - an oops on bootup, or a non-working
> watchdog?
it just won't work at boot time - the second logic unit will be stuck:

Booting processor 1/2 APIC 0x1
Initializing CPU#1
Calibrating delay using timer specific routine.. 5586.12 BogoMIPS (lpj=2793063)
CPU: Trace cache: 12K uops, L1 D cache: 16K
CPU: L2 cache: 1024K
CPU: Physical Processor ID: 0
CPU: Processor Core ID: 1
CPU1: Thermal monitoring enabled (TM1)
Intel(R) Pentium(R) D CPU 2.80GHz stepping 04
Brought up 2 CPUs
testing NMI watchdog ... <4>WARNING: CPU#1: NMI appears to be stuck (0->0)!

--
Aristeu

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