x86_64 smp 2.6.15-1.1781_FC4 in ?

[dragoran]

Dave Jones wrote:

>On Tue, Jan 03, 2006 at 02:15:35PM +0100, dragoran wrote:
>
> > >Do you mean why not have a non-smp kernel for x86_64? If so probably 
> > >because many(most?/all?) EMT64 CPUs support HT or dual core.
> > >
> > there are many non dualcore am64 chips arround
>
>lock prefix on uniprocessor AMD systems is a lot lower overhead
>than it is on Intel. The performance impact of running with spinlocks
>on UP there is tiny. The gain is that we save shipping an extra
>kernel on the CD, the installer gets simpler, and we have a single
>codepath on that architecture.
>
>There is work ongoing upstream that may make it in for 2.6.16 to
>actually nop out the spinlocks on UP configurations, making them
>completely free.
>
> > http://people.redhat.com/davej/kernels/Fedora/FC4/RPMS.kernel/kernel-2.6.15-1.1781_FC4.x86_64.rpm
> > and 
> > http://people.redhat.com/davej/kernels/Fedora/FC4/RPMS.kernel/kernel-smp-2.6.15-1.1781_FC4.x86_64.rpm
> > smp is already enabled in the non smp kernel.. so why do we have 2 
> > kernels with different names but same config? (or is there a difference 
> > beween them)
>
>The unification happened after FC4 was released. FC5 will be the
>first single-kernel x86-64 release.
>
>		Dave
>
>  
>
ok thanks for the info.