Watchdog Timeout - bge devices
Scott Long
scottl at samsco.org
Wed Oct 4 05:38:36 UTC 2006
David G Lawrence wrote:
>> Very interesting data point. I wonder if this accounts for some of the
>> inconsistency in the reporting from others. In any case, SCHED_ULE is
>> still considered to be highly experimental. Hopefully it will get some
>> more attention in the near future to bring it closer to production
>> quality.
>
> I'm not using SCHED_ULE on any of the machines that I'm seeing the
> timeout problem with em and fxp devices. I suspect the problem has to do
> with interrupt thread scheduling; maybe SCHED_ULE just somehow makes the
> problem worse?
>
> -DG
>
Well, the two things that will block the scheduler are critical sections
and spinlocks. The system will complain about spinlocks that are held
too long, but you might need WITNESS and/or INVARIANTS enabled for it.
Critical section debugging is almost non-existant; the only way to do it
is to turn on KTR and then feed the output to schedgraph.py. This only
works reliably for UP, though.
Scott
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