On Thu, Oct 19, 2006 at 01:33:40AM -0400, Len Brown wrote: > On Wednesday 18 October 2006 18:24, Dave Jones wrote: > > I've been chasing a bug that got filed against the Fedora kernel > > a while back: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=199052 > > This is a dual pentium pro from an era before we had ACPI, and > > it seems to be falling foul of this test in smpboot.c .. > > > > if (!smp_found_config && !acpi_lapic) { > > printk(KERN_NOTICE "SMP motherboard not detected.\n"); > > > > My initial reaction is that the !acpi_lapic test should be conditional > > on some variable that gets set if the ACPI parsing actually succeeded. > > acpi_lapic isn't related to the problem at hand -- that smp_found_config is not set. Right, it just seemed odd to me when I was eyeballing this code. > That said, allowing acpi_lapic=1 to bail out of this check has the sole > function of allowing SMP/PIC configurations. (smp_found_config > in ACPI mode is set if acpi_lapic and acpi_ioapic are set) > SMP/PIC configurations are not very interesting, except for debugging. > Indeed, MPS prohibits them by mandating an IOAPIC be present for SMP -- > but ACPI has no such rule. Why smp_found_config isn't set in that guys configuration is a mystery to me, as his MPS tables look sane.. MP Table: # APIC ID Version State Family Model Step Flags # 0 0x10 BSP, usable 6 2 1 0x0381 # 0 0x10 AP, usable 6 1 7 0xfbff Hmm, wait, he has unpaired CPUs. I wonder if that's the reason. I know *some* combinations of PPro's are valid to be paired, but I'll need to dig out the old docs to be sure. Dave -- http://www.codemonkey.org.uk - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
