[2.6.12] x86-64 IO-APIC + timer doesn't work

From: Alistair John Strachan
Date: Sat Jun 18 2005 - 08:53:31 EST


I upgraded my nForce3 x86-64 desktop from 2.6.12-rc5 to 2.6.12 today and
something strange started happening. Waay back in 2.6.x I had problems with
the "noapic" default for nForce boards on x86-64, and so used the "apic"
kernel boot parameter to force the apic on; this worked successfully for a
long time with no timer problems.

However, as of 2.6.12 (maybe -rc6, too?) my desktop occasionally fails to boot
with the message:

"IO-APIC + timer doesn't work! Try using the 'noapic' kernel parameter."

However, this message is intermittent; it is sometimes possible to boot
without getting it, and everything works fine. So I took its advice and ran
with noapic, and everything seems fine now.

However, I just thought I'd let whoever maintains this bit of code know that
the check isn't a "sure thing": it's not being flagged reliably. Whether this
is my BIOS or the kernel, I don't know.

Though I clearly don't require this functionality any more, is there any
reason I now can't use apic on this nForce3 board, where previously (on
2.6.12-rc5 and older) I could?


personal: alistair()devzero!co!uk
university: s0348365()sms!ed!ac!uk
student: CS/CSim Undergraduate
contact: 1F2 55 South Clerk Street,
Edinburgh. EH8 9PP.
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