Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!ssbell!dsndata!wayne
From: wayne@dsndata.uucp (Wayne Schlitt)
Newsgroups: comp.sys.hp
Subject: Re: HP 9000/400 question
Message-ID: <WAYNE.90Aug12150209@dsndata.uucp>
Date: 12 Aug 90 19:02:09 GMT
References: <j902s89@Unify.Com> <7370192@hpfcso.HP.COM>
Sender: wayne@dsndata.UUCP
Organization: Design Data
Lines: 26
In-reply-to: rjn@hpfcso.HP.COM's message of 10 Aug 90 18:46:16 GMT

In article <7370192@hpfcso.HP.COM> rjn@hpfcso.HP.COM (Bob Niland) writes:
> re: >> Your self-modifying code for your 300 will work fine on your 400, (but
>     >> will break on both 300 & 400 when you upgrade to 68040 with copyback
>     >> cache enabled :-)
> 
> [ ...  ]
> 
> > Hopefully there will be some system call in future versions of HP-UX to
> > flush the complete cache system back to memory (and invalidate I-cache
> > entries).
> 
> There will, and in the '040 release (be that 7.05 or 8.0).
> 

(there was a similar thread in comp.arch about the problems of self
modifying code and caches...)


pardon my ignorance, but why does the 040 break things worse than the
030?  dont they both have separate instruction and data caches?   the
only difference that i know of is the fact the the 030's caches are
tiny (256 bytes for I & D) and therefor you are not as likely to
encounter problems.


-wayne