Deadlocks with recent SMP current
scottl at samsco.org
Fri Aug 13 13:11:38 PDT 2004
Lukas Ertl wrote:
> On Fri, 13 Aug 2004, Robert Watson wrote:
>> will eventually get a solid hang. I tried it on a new SMP box with an
>> button I received yesterday but was unable to get into the debugger. I'm
>> in the process of de-obfuscating the NMI path to increase the chances of
>> successfully getting into the debugger and then I'll try again to see
>> I can figure out.
> I have an NMI-enabled SMP box too, and the only message I got when
> sending an NMI to the deadlocked system was 'kernel trap 12 with
> interrupts disabled', but nothing more.
> If you want me to test something, feel free to shout out.
The NMI handler(s) try to do far too much and often get caught up in
mutexes. I've locally changed it to just call either kdb_backtrace() or
kdb_enter() and then reboot. We might want to consider looking for
a general solution for this in 5.3.
More information about the freebsd-current