Re: Why do so many machines need "noapic"?

From: Chuck Ebbert
Date: Thu Sep 13 2007 - 12:38:58 EST


On 09/10/2007 03:44 PM, Andi Kleen wrote:
>> Yes, it has an hpet. And I tried every combination of options I could
>> think of.
>
>> But, even stranger, x86_64 works (only i386 fails.)
>
> x86-64 has quite different time code (at least until the dyntick patches
> currently in mm)
>
> Obvious thing would be to diff the boot messages and see if anything
> jumps out (e.g. in interrupt routing).
>
> Or check with mm and if x86-64 is broken there too then it's likely
> the new time code.

I reported too soon that x86_64 works. It does not work, it just takes
a bit longer before it freezes. There are message threads all over the
place discussing this problem with the HP Pavilion tx 1000, and it seems
the best workaround is to use the "nolapic" option instead of "noapic".
Using that, it is totally stable _and_ there are no spurious interrupts
that would otherwise break USB. Interrupt setup is a bit strange, though:

CPU0 CPU1
0: 241 0 XT-PIC-XT timer
1: 1 736 IO-APIC-edge i8042
2: 0 0 XT-PIC-XT cascade
5: 14 10028 IO-APIC-edge sata_nv
7: 0 57 IO-APIC-edge ehci_hcd:usb1
8: 0 0 IO-APIC-edge rtc0
9: 4 2463 IO-APIC-edge acpi
10: 2 2795 IO-APIC-edge HDA Intel
11: 740 478806 IO-APIC-edge ohci_hcd:usb2, eth0
12: 42 19911 IO-APIC-edge i8042
14: 5 7958 IO-APIC-edge libata
15: 0 0 IO-APIC-edge libata
NMI: 0 0
LOC: 4617310 4617213
ERR: 0
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