--- Christopher Mahmood
It's feature of certain x86 chipsets to increase the number of interrupts. You can read all about it in /usr/src/linux/Documentation/i386/IO-APIC.txt
The first paragraph says: "Most (all) Intel-MP compliant SMP boards have the so-called 'IO-APIC', which is an enhanced interrupt controller, it enables us to route hardware interrupts to multiple CPUs, or to CPU groups." So why is it switched on in the default, single CPU kernel? After someone suggested this might be the problem, I had a look at my boot logs. There's a message about APIC is switched off in the BIOS. Linux then switches it on. Surely it shouldn't be overriding the BIOS settings?
The problem is that some buggy chipsets have a broken implementation that doesn't work, some don't have one, and some have one that works around other bugs. We chose to enable it by default in the default kernel (although not in the i386 kernel I think) this
And that decision cost me three days of swearing and multiple fsck runs with who knows what files ending up in lost+found. I only managed to find the relevant entry in the support database when I already knew APIC was probably the problem. If you're going to switch on features which cause complete system crashes and data loss, do you think a great big warning somewhere might be a good idea? Jason __________________________________________________ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com