Subject: Re: NetBSD-1.5A on dual cpu SS20: panic: lockmgr: no context
To: Brad Spencer <brad@anduin.eldar.org>
From: Paul Kranenburg <pk@cs.few.eur.nl>
List: tech-smp
Date: 06/29/2000 13:13:52
>    panic: lockmgr: no context
> 
> For what it is worth....
> 
> I get the same thing on a SS10 with a dual Ross 100 MHZ module.  It didn't
> happen, however, when I had two TMS390Z50 in the machine.
> 
> I presumed that something is not quite ready.

True. MP hypersparc machines all do this. The problem is in the smp
version of the cache flush routines: pages must remain mapped in the
MMU until the page cache flushes are done on all CPUs. Currently,
the primary CPU races ahead and unmaps a page before the other CPUs
get around to flushing it from their caches.

At least that's my current conjecture on this issue.

-pk