AT&T "nth Edition" vs. "Release n"

Tim Wright tim at dell.co.uk
Wed Mar 6 22:55:46 AEST 1991


In <15385 at smoke.brl.mil> gwyn at smoke.brl.mil (Doug Gwyn) writes:

>In article <10556 at dog.ee.lbl.gov> torek at elf.ee.lbl.gov (Chris Torek) writes:
>>Until recently, for instance, the `base' technology in System V (by
>>which I mean `the algorithms that had not been rewritten or otherwise
>>fixed to handle modern systems') dated back to the mid 1970s, rather
>>than the mid-1980s (which is when many of the `base' algorithms in the
>>4.2BSD kernel were redone [FS & IPC; the VM was left rotting and is
>>only now being fixed---but at least expansion swaps were just a last
>>resort, rather than an everyday occurrence as in SysV]).

>In fact UNIX System V was not using the virtual memory system to which
>Chris refers any time in the recent past.  Before the switch to VM a
>la Sun, UNIX System V had been using a "region"-oriented system based
>on concepts similar to DEC's VAX/VMS.

True, but is it not true that all SysVs until 4.0 still have the obnoxious
expansion swap code. I'm pretty sure they do and it has horrendous
performance implications. It's like the way fsck complains about possible
file size errors on FIFOs. They've only been around for 5+ years - you
would have thought somebody in the USG could have taught fsck about
them :-(.

Tim
--
Tim Wright, Dell Computer Corp., Bracknell    |  Domain: tim at dell.co.uk
Berkshire, UK, RG12 1RW. Tel: +44-344-860456  |  Uucp: ...!ukc!delluk!tim
Nobody ever said I was charming before. They said, "Rimmer, you're a total git"
- Red Dwarf, "Camille".



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