Kernel Optimizations for Processors

[John Baldwin]

On 29-Dec-2003 admin at forkthepenguin.com wrote:
>> > # NO_F00F_HACK disables the hack that prevents Pentiums (and ONLY
>> > # Pentiums) from locking up when a LOCK CMPXCHG8B instruction is
>> > # executed.  This option is only needed if I586_CPU is also defined,
>> > # and should be included for any non-Pentium CPU that defines it.
>>
>> 'and ONLY Pentiums'
> 
> It also says "should be included for any non-Pentium CPU that defines it"
> but how do you know if the C# defines this? Is this another item that
> would show up in the "Features" list? I looked at a PI-133 I have and
> don't see it :

It means that if you have 'cpu I586_CPU' in your kernel config and
you aren't running a Pentium, then you can define this option.  However,
it won't really buy you much since we only install the F00F hack once
during bootup and all adding this option will do is just not check for
it at bootup.

-- 

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