[prev in list] [next in list] [prev in thread] [next in thread] 

List:       linux-smp
Subject:    Re: WARNING: unexpected IO-APIC; all interrupts to one CPU on  smp
From:       "E. Robert Bogusta" <rob23 () tmr ! com>
Date:       2002-06-18 14:10:23
[Download RAW message or body]

On Thu, 23 May 2002, Earle Nietzel wrote:

Just a note on several of these suggestions...
 
> This message has nothing to do with the your performance problems or why 
> all interrupts go to one CPU.
> 
> This message is for the ACPI (IO-APIC included) maintainers to keep an eye 
> on when there is new hardware.
> 
> You should make sure that your MPS setting is set to 1.1 not 1.4 (BIOS option).

I got this information from multiple sources including Alan and IBM.
However, on at least some Netfinity models (8658 for sure) and BIOS
revisions (12? anyway latest as of June 1 2002) this causes the kernel to
spend most of an hours diddling the onboard SCSI, then getting a lockup.
I've tried this on other Netfinity and it has never fixed anything, so I
don't do it. YMMV.
 
> Also boot without passing the noapic option to the kernel. This option 
> causes all interrupts go to CPU0 (bypassing the new 2.4 ACPI stuff).

Alan and others do not agree. I have been using noapic and having
stability, on Netfinity, BP6, and Intel boards. If you see lockups or
other problems under heavy load, try noapic, the performance hit is lower
than I can measure, certainly lower than a solid lockup.

		-- rob bogus

-
To unsubscribe from this list: send the line "unsubscribe linux-smp" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
[prev in list] [next in list] [prev in thread] [next in thread]