Alpha problems (though maybe not just Alpha...)

FYI, the Alpha reference machine in the cluster has had problems the
past few days when anything significant (e.g. 'make buildworld'...)
gets run on it.  It usually locks up solid right after printing
this on the console:

panic() at panic+0x200
_mtx_assert() at _mtx_assert+0xb4
vrele() at vr 16 32 48 64 80
fatal kernel trap:

    trap entry     = 0x2 (memory management fault)
    cpuid          = 0
    faulting va    = 0x0
    type           = access violation
    cause          = instruction fetch
    pc             = 0x0
    ra             = 0x0
    sp             = 0xfffffe00317bfc70
    curthread      = 0xfffffc007d772000
        pid = 23, comm = intr: ahc1

spin lock sched lock held by 0xfffffc007d772000 for > 5 seconds

A kernel built July 2nd doesn't seem to have this issue.  I haven't
had time to play the 'find-which-commit-breaks-it' game yet.  My
guess is that this is not Alpha specific but that's just a guess,
the amd64 ref machine in the cluster has been pretty fragile the
past few days as well though it usually just locks up solid with
nothing useful on the console.  Both are dual processor machines.

I had built a kernel for Alpha last night to test something for
someone so Robert's commit yesterday backing off some aspects
of the scheduler doesn't appear to have been the problem causing
this.

-- 
						Ken Smith
- From there to here, from here to      |       kensmith_at_cse.buffalo.edu
  there, funny things are everywhere.   |
                      - Theodore Geisel |