Subject: Re: lock errors on DIAGNOSTIC kernel after yamt-idlelwp merge
To: Izumi Tsutsui <firstname.lastname@example.org>
From: Michael L. Hitch <email@example.com>
Date: 05/19/2007 16:05:22
On Sat, 19 May 2007, Izumi Tsutsui wrote:
>> Modified Files:
>> src/sys/arch/m68k/m68k: pmap_motorola.c switch_subr.s vm_machdep.c
>> Log Message:
>> Common m68k changes for idlelwp.
> Does a DIAGNOSTIC kernel work on amiga?
Did this work after the newlock2 merge (before the idlelwp merge)?
> On hp300 (and also news68, sun3, sun3x) DIAGNOSTIC kernels
> get the following mutex error during SCSI probe:
> hpibbus4 at nhpib4
> interrupt levels: bio = 4, net = 5, tty = 5
> scsibus0: waiting 2 seconds for devices to settle...
> Mutex error: mutex_vector_enter: locking against myself
> lock address : 0x00000000001e67c0
> current cpu : 0
> current lwp : 0x0000000003641d80
> owner field : 0x0000000027008000 wait/spin: 0/1
> panic: lock error
My amiga has the same problem. The scsibus0 lwp has the lwp locked
when sched_pstats() run (as well as the other 2 non-idle lwps.
Hmm, some debugging shows that cpu_switchto never returns when switching
to a newly created lwp. This leaves the old lwp locked, and when
sched_pstats() get called while scsibus0 is sleeping for the 2 second
delay, the DIAGNOSTIC check fails. This may also explain why my
non-DIAGNOSTIC amiga kernel seems to lose time: a 'locked' lwp is at
IPL_HIGH until it is unlocked.
And I now see that I'm missing some stuff when starting up a new process
(it wasn't mentioned in doc/BRANCHES). I'll fix that and see if things
Michael L. Hitch firstname.lastname@example.org
Information Technology Center
Montana State University Bozeman, MT USA