Kernel for Dual Core

[Mark Ovens]

Jos Chrispijn wrote:
> Mark Ovens wrote:
>> What version of FreeBSD? IIRC, in 7.0 GENERIC is SMP-enabled by default?
> Yep, it is...
>> As for your kernel config file you should remove/comment out anything 
>> you don't have, e.g. wireless LAN, EISA, USB NICs, RAID, SCSI etc. - 
>> although be aware that USB Mass Storage devices are handled as SCSI so 
>> if you use any of those I'd leave everything in the SCSI Peripherals 
>> section and just remove the SCSI Controllers.
> What I don't understand: if you do a cdrom install of FreeBSD, the 
> Kernel is based on GENERIC.
> If I look in GENERIC, most items are not hashed out and there are parts 
> of them that my hardware does not use. And still it works.
> Why then not use the 7.0 GENERIC for my dual core system?
> 

You can use the GENERIC kernel. I've just checked and GENERIC in 7.0 
does indeed have SMP enabled by default.

The reason that nothing is #'d out and just about everything is in 
GENERIC is because it is exactly that, a *generic* kernel, and soo needs 
to be able to boot on any hardware it's installed on.

The advantage of building a custom kernel is that you remove anything 
your system doesn't have which saves time when booting as the kernel 
won't be probing for devices that it will never find - for example. mine 
is an all-SCSI system so my kernel doesn't have any IDE or floppy 
devices in it - and it makes the kernel smaller (although that isn't 
really an issue these days).

An alternative is to go into the configuration editor from the main boot 
menu and disable those compiled-in devices that you don't have.

To confirm that your running kernel has detected and started both CPUs:

/home/mark{8}% grep -i cpu /var/log/messages

May 26 12:10:30 redshift kernel: CPU: AMD Athlon(TM) MP 2800+ 
(2133.42-MHz 686-class CPU)
May 26 12:10:30 redshift kernel: FreeBSD/SMP: Multiprocessor System 
Detected: 2 CPUs
May 26 12:10:30 redshift kernel: cpu0 (BSP): APIC ID:  0
May 26 12:10:30 redshift kernel: cpu1 (AP): APIC ID:  1
May 26 12:10:30 redshift kernel: cpu0: <ACPI CPU> on acpi0
May 26 12:10:30 redshift kernel: cpu1: <ACPI CPU> on acpi0
May 26 12:10:30 redshift kernel: SMP: AP CPU #1 Launched!
/home/mark{9}%

Regards,

Mark