Re: NMI problems with Dell SMP Xeons

Keith Owens
2006-06-08T05:11:33Z

"Brendan Trotter" (on Wed, 7 Jun 2006 15:18:57 +0000) wrote:
>Hi,
>
>On 6/7/06, Keith Owens <kaos@sgi.com> wrote:
>> This problem is not KDB specific, although that is where it was first
>> noticed. Any code that sends a broadcast IPI 2 or an NMI IPI will
>> crash these Dell boxes when there is a mismatch between the cpus known
>> to the BIOS and the cpus known to the OS.
>
>I missed this (broadcast IPI 2 causing problems)...

It turns out that there is an uncommented hack in x86_64's version of
__prepare_ICR().

case NMI_VECTOR:
icr |= APIC_DM_NMI;
break;

That hack is not in i386, which means that IPI 2 does different things
in i386 vs. x86_64 mode on the same hardware. I am still tracking down
all the differences before doing a clean up patch that makes i386 and
x86_64 behave the same.