Subject: Re: spontaneous coredumps?
To: Hauke Fath <hauke@Espresso.Rhein-Neckar.DE>
From: Todd Whitesel <toddpw@best.com>
List: port-mac68k
Date: 11/13/1999 04:59:20
> At 13:02 Uhr +0100 12.11.1999, Todd Whitesel wrote:
> >[ please keep me in the cc: list as I do not subscribe to port-mac68k ]
> >
> >I have a few IIci's here which I have been trying to bring from 1.4.1 to
> >-current. However, they seem to be suffering from fairly frequent spontaneous
> >coredumps. ...

> first thing that comes to mind: Which 53c80 SCSI driver do you use? And
> have you tried the other one (there are two, sbc and ncrscsi)? Next, there
> may be hardware problems (RAM).

I have been using the "GENERIC" kernel without any modifications.

Can't rule out RAM yet, but it doesn't feel like it. I get similar failures
on two IIci's whose configurations are identical (cache card, 20mb, ae0 at
nubus, no other cards) -- I just moved the 500 mb hard drive from one to the
other.

Last night I tried something else; to rule out NFS as a factor, I hooked up
an external 323mb hard drive and newfs'd it so it would have enough space to
handle a complete set of sources (took two tries to get the inode density
right, however). This was mounted as /dev/sd1c /usr/src, and I was able to
do a cvs checkout (of /usr/src/src because cvs insists on creating all of its
controlled directories) without incident.

While building a kernel I ran into the % transition in the assembly code,
and built/installed gas. After that the kernel build proceeded reasonably
far along before dying; interestingly, it didn't die of a core dump event,
but rather due to misspellings in .depend ("don't know how to make xxxx").
Two of them:
	./../../../sys/types.h
	../../../../syss/dirent.h

Now the twilight zone klaxon is _really_ going off. Dropped/duplicated bytes
is a very scary kind of failure.

I just tried hacking the huge mkdep line for .c files to use xargs -n 10,
and it only seems to have moved the failures around in the file. Worse, I
now appear to have a very unhappy assembler. Something tells me it's time
to wipe these macs and start over from 1.4.1.


BTW, as I recall the 68k Macintoshes never really supported SCSI Arbitration,
ever. This was frequently declared to be a software problem, in the form of
non-existent support for it by the Mac Toolbox SCSI Manager.  But perhaps it
is related to a real hardware issue, since the hardware was never tested
against an arbitrating SCSI driver?

Is it possible to run our scsi drivers without disconnect/reselect, and has
anyone tried this on mac68k to see if it improves anything?

Todd Whitesel
toddpw @ best.com