HEADSUP: New i386 interrupt and SMP code..

[John Baldwin]

On 30-Oct-2003 Brooks Davis wrote:
> On Thu, Oct 30, 2003 at 05:34:47PM -0500, John Baldwin wrote:
>> - The ACPI MADT table can be used to enumerate CPUs instead of
>>   the MP Table if ACPI is enabled.  This will add true HT support
>>   in that we will finally support the BIOS setting for HT.
> 
> Will there be an option to ignore the BIOS and do something like the
> current system?  I'm all for paying attention to the BIOS, but I've got
> over 75 Xeons in my cluster and if they have the wrong BIOS settings,
> this is going to hurt when we switch to 5.x.

It's actually not safe to ignore the BIOS.  We have one 750x based
system here at work that doesn't boot a 4.x kernel with HTT enabled
(the logical CPUs don't ack the IPI) unless HTT is also enabled in
the BIOS.

> Overall, I'm looking forward to this change.  The death of the SMP
> kernel is something I've been looking forward to for a long time.

It was a question asked of Jordan at the first Usenix BSD BoF I
attended back in 2000 in San Diego. :)

-- 

John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve!"  -  http://www.FreeBSD.org/