On Thu, Nov 29, 2007 at 07:54:16PM -0700, Eric W. Biederman wrote:
I've got a system here that now seems to be behaving in a way that is simmilar
to what Ben describes (although I'm not sure its the same problem).
early_printk shows that we're panic-ing inside check_timer, because we fail to
find any way to route the timer interrupt to the cpu. Specifically, we're
hitting this panic:
panic("IO-APIC + timer doesn't work! Try using the 'noapic' kernel
parameter\n");
This doesn't make much sense to me, as we clearly have managed to get timer
interrupts at this point (since we made it through calibrate_delay)....
Looking at it, I wonder if this isn't a backporting issue. Ben and I ran this
test on an older kernel (since thats what the production system under test is
based on). Currently, check_timer is called directly from within setup_IO_APIC,
but in the 2.6.18 kernel that RHEL5 is based on its part of an initcall thats
run from within init near the call site of the origional io apic init code. I
wonder if this isn't just an 'old kernel' issue, and that I need to move
check_timer to inside setup_IO_APIC.
Ben, is it possible for you to run an upstream kernel on one of these systems so
we can see if the patch works in that case? In the interim, I'll update my
patch for 2.6.18 so that check_timer gets moved earlier
Neil
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