Subject: Re: SCSI Screw-ups
To: Michael R Zucca <mrz5149@cs.rit.edu>
From: Bill Studenmund <wrstuden@loki.stanford.edu>
List: port-mac68k
Date: 09/10/1997 11:53:45
>                   Now I added a little code
> and the SCSI phase errors return. It all seems
> to revolve around kernel size.
> 
> I'd really like to get to the bottom of this
> problem. Does anybody have any idea how this
> could get solved? It's making testing impossible.
> I have to look throuhg 100's of SCSI errors
> which are self generating (they cause the message
> daemon to write to disk which casues further
> \errors!)

I'm not sure what to do, but here's a start.

Can you get these error in r/o mode? That way you can
test w/o damaging stuff..

One thing to do to slow down the errors is to make them log to a
memory disk. Check out mount_mfs. You can create a memory
disk in your /etc/fstab, and when the startup scripts try to
mount it, they'll create it. Technically it uses swap, but if
your memory use is low, it shouldn't try to swap, so no problem.

The other thing is we need some big-guns help w/ kernel memory layout.
Basically the only thing I can think of is for us (well, you)
to figure out where things are in the kernel image, and try adding
extra padding in various places. Like figure out what moved
between kernels, and then try hacks to bload code further on
in the kernel.

The idea is to bracket the problem (if possable), If bloating
something at 32% of the kernel has problems and bloat at 50%
doesn't, moving things inbetween is the problem..

Does that make sense?

I think we might be in for learning something really weird about Apple
hardware.

Take care,

Bill