Re: SMP broken on pre-ACPI machine.

From: Sergio Monteiro Basto
Date: Wed Oct 18 2006 - 19:45:50 EST


On Wed, 2006-10-18 at 18:24 -0400, 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");
> smpboot_clear_io_apic_irqs();
> phys_cpu_present_map = physid_mask_of_physid(0);
> if (APIC_init_uniprocessor())
> printk(KERN_NOTICE "Local APIC not detected."
> " Using dummy APIC emulation.\n");
> map_cpu_to_logical_apicid();
> cpu_set(0, cpu_sibling_map[0]);
> cpu_set(0, cpu_core_map[0]);
> return;
> }
>
>
> My initial reaction is that the !acpi_lapic test should be conditional
> on some variable that gets set if the ACPI parsing actually succeeded.
>
> Thoughts?
>
> Dave
>

acpi=off ? this machine should work with APM. BTW, so time ago, this
machine would enter in ACPI blacklist (by the year of bios) and ACPI was
turned off automatically.

--
Sérgio M.B.

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