In the 2.4.30/31 kernels there is now a backport from the 2.6 kernels of 
a workaround for buggy timer overrides in the ACPI tables for many 
nvidia chipset based motherboards.  Unfortunately the code for this on 
x86-64 based systems is conditionally compiled in only for non-SMP 
kernels.  This is a patch to remove the conditional and allow the code 
to be compiled in for SMP kernels as well (we've seen a number of SMP 
motherboards which intermittently lock up during boot, and otherwise 
sometimes seem unstable without the workaround).  Patch so far has been 
tested across numerous reboots and several hours uptime.

Also part of this patch is modifications to avoid referencing the 
variable "swiotlb" from pci-gart.c when CONFIG_SWIOTLB is not set; 
without modification, an x86_64 kernel without CONFIG_SWIOTLB set breaks 
during compilation of arch/x86_64/kernel/pci-gart.c.

All small changes & straightforward; don't think there's anything to 
worry about WRT enabling the override workaround code on SMP boxes, 
although I'd appreciate verification from someone more familiar with the 
setup code.

Thanks,

-Tymm