eichelbe@NADC (05/10/85)
Here's the $64,000 question: What's wrong with a VAX 11/780 under 4.1 BSD when it halts with the message: panic: pagein mfind Any responses as to what this message really means would be appreciated. Thanks. Jon Eichelberger eichelbe@NADC
chris@umcp-cs.UUCP (Chris Torek) (05/11/85)
Well, mfind is a routine that finds the ``core map'' entry (if any)
for a particular block on a file system. pagein will panic if you
get a page fault on a text page, mfind finds it in the core map, but
the core map entry says that it's not a text page, that it's not
``gone'' (i.e., hasn't been freed), or that it's not free. Why any
of those should happen I have no idea. . . .
--
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 4251)
UUCP: {seismo,allegra,brl-bmd}!umcp-cs!chris
CSNet: chris@umcp-cs ARPA: chris@marylandbruce@think.ARPA (Bruce Nemnich) (05/13/85)
I know of two possibilities. First, if you installed a certain "fix" which appeared in the security-issues mailing list, for which an alternate (and better) fix was given in that forum recently (if you are a recipient of that list you should understand), it can cause a panic "pagin mfind" under certain circumstances. Try running dbx on anything, "stop in main", and "run". When it breakpoints, stop (^Z) the dbx, and try running the program. If you panic, that's the problem (I know from experience). I also saw a bug report a few months back which will cause it if there are more than 127 copies of a text image running. A one-byte field with the count is getting sign-extended. I have not fixed this nor seen it myself. -- --Bruce Nemnich, Thinking Machines Corporation, Cambridge, MA --bruce@think.arpa, ihnp4!think!bruce; +1 617 876 1111