panic on 5.2 BETA: blockable sleep lock

Don Lewis truckman at
Sun Nov 30 03:01:13 PST 2003

On 30 Nov, Stefan Ehmann wrote:
> On Fri, 2003-11-28 at 01:02, Don Lewis wrote:
>> On 27 Nov, Stefan Ehmann wrote:
>> > On Wed, 2003-11-26 at 08:33, Don Lewis wrote:
>> >> The problem is that selrecord() wants to lock a MTX_DEF mutex, which can
>> >> cause a context switch if the mutex is already locked by another thread.
>> >> This is contrary to what bktr_poll() wants to accomplish by calling
>> >> critical_enter().
>> > 
>> > Strange enough that does not seem to happen with a kernel built without
>> > INVARIANTS and WITNESS. Does this make any sense or is this just by
>> > chance?
>> You might try the patch below with WITNESS enabled.  I don't have the
>> hardware, so I can't test it.  It compiles for me, but for all I know it
>> could delete all your files if you run it.
> Any chance for getting this committed?

I've been forwarding these messages to the bktr maintainer listed in
/usr/src/MAINTAINERS, in case he isn't subscribed to current at .  I'm not
suprised that I haven't heard from him because this issue came up at the
start of the Thanksgiving holiday weekend.  Commiting the patch will
also require re approval because of the code freeze in preparation for

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