On Wed, Jul 06, 2005 at 02:34:40PM +0200, Thomas Woerner wrote: > Arjan van de Ven wrote: > >On Wed, 2005-07-06 at 07:13 -0400, Build System wrote: > > > >>- Drop x86-64 SMP kernels, and make generic kernel use SMP. > >why is this?? > Why only for x86_64? 32 bit has a lot more history of crap hardware. It's almost guaranteed that there are 32bit UP boxes out there that won't boot the SMP kernel. (In fact, it's certainly guaranteed because the 686-smp kernel uses PAE, which not all 686's have) x86-64 has had an APIC since day 1. It hasn't had to worry about crap like PAE. As it doesn't have this baggage, the decision is a lot easier to make there. I spent a while going over the list of current 32bit kernels trying to figure out a way to drop one of them. - Dropping 586 kernels would likely get AMD K5/K6, Cyrix, VIA users screaming. - Forcing all the non-PAE CPUs to use the 586 kernel and dropping the 686-UP kernel would get all the "my kernel isn't optimised for my hardware" people screaming. So 32-bit is very likely going to stay exactly the way it is today. One change that might happen though -- there are newer CPUs that have (or will have soon) NX capability, but aren't SMP. (VIA have a chip ready, Intel are alleged to be putting NX in their next line of laptop processors, probably AMD too). To take advantage of NX, you need PAE enabled, which means these kernels will need to run 686-smp even though they aren't smp. I'll probably be doing some lobbying in Jeremy's cube for an installer change on this hardware when I get some to test with. Given that using NX on 32bit is a big win due to us being able to use sysenter again, this is a very attractive feature. Dave -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx http://www.redhat.com/mailman/listinfo/fedora-devel-list
