Re: perf sched record hangs machine

From: Ingo Molnar
Date: Wed Sep 23 2009 - 03:33:24 EST



* Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> .size default_send_IPI_self, .-default_send_IPI_self
>
> Which seems to suggest that cmove is in __prepare_ICR, but I'm not
> sure how that can cause a page-fault, as that function is rather
> pointer-less.
>
> Did it maybe delay evaluating apic->dest_logical that late, it appear
> to be the first usage of that argument?
>
> Ingo, any ideas?

Yeah, the problem is:

[ 0.042445] Local APIC not detected. Using dummy APIC emulation.

we shouldnt be trying to program the lapic in that case - all ops should
be a NOP, including send-ipi-self. Cyrill?

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/