sio: lots of silo overflows on Asus K8V with MoxaSmartioC104H/PCI solved

[Bruce Evans]

On Tue, 4 May 2004, Carlos Velasco wrote:

> On 05/05/2004 at 0:04 Bruce Evans wrote:
>
> >So much for my theory that the problem is contention with a low priority
> >thread.  Since holding a spin lock or otherwise disabling interrupts for
> >too long would also break the PUC_FASTINTR case, the problem must be that
> >the highest priority runnable thread (which with my patch can only be the
> >sio (puc) ithread if that thread is runnable) is not always run.  This is
> >quite likely to be just the old bug that handling of interrupts which
> >can't be handled immediately might be delayed for too long.  From
> >ithread_schedule():
>
> Bruce,
>
> Could this be relationated to my problem with "interrupt-level buffer
> overflows " posted on next thread?
> http://lists.freebsd.org/pipermail/freebsd-current/2004-May/026697.html

Your problem seems to be different because you get interrupt-level
overflows instead of silo overflows.  There is nothing corresponding
to PUC_FASTINTR in for pccards, so I would have expected silo overflows
if anything.

Bruce