joerg@uunet.uu.net (Joerg Schilling - H. Berthold AG Berlin) (05/11/89)
I ran into this panic in Oct 1988 when I wrote a device driver that allows
a file containing an image of a filesystem to be "mounted". Whenever I
use the "blockdevice" I have no problems at all. But when I use the "raw"
device extensively (several fsck(8) passes) the system panics with the
message:
vmunix: panic: hat_unload - pmg not kept
The routine hat_unload() is part of the new vm stuff in SunOS 4.0x. "Hat"
means hardware adress translation; it is used as part of the new type
caching for shared text and filesystem buffering.
On the SUG conference on dec 1988 in Miami I asked a unix guru from sun
about that panic, and he told me that my driver must be wrong. But I
double checked my driver and I am shure that my driver is correct.
My opinion is, that the panic is a result of sun's vm stuff is doing
something wrong with the keepcount. But as I can only repeat it with my
driver I cannot report it to sun's hotline.
So everyone who has had this panic by only using sun code, please report
it to sun's "hotline" I hope they will beleve yout that's a bug.
J. Schilling
H. Berthold AG
Teltowkanalstr. 1-4
D 1000 Berlin 46
+49 30 7795 - 400
joerg@berthold.de
... tub!berthold!joerg
... unido!berthold!joerg