From: dg AT dcs DOT st-and DOT ac DOT uk
Message-Id: <23289.9702150225@orkney.dcs.st-andrews.ac.uk>
To: opendos AT mail DOT tacoma DOT net
Subject: Re: [opendos] Re: [opendos-developer] Caching 
In-Reply-To: yeep@xs4all.nl's message of Fri, 14 Feb 97 19:36:39 +0100.
	     <199702150017 DOT BAA12635 AT magigimmix DOT xs4all DOT nl> 
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Date: Sat, 15 Feb 97 02:25:33 +0000
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[...]
>Yes, but in the text above I said that in Linux (or any other MultiTasking
>enviroment for that matter) it's ready when the process ends in stead of
>when the prompt is back.
[...]

No, it doesn't. Buffers are only flushed when a sync() occurs or the device is 
unmounted. No other time. So, I frequently do:

mount /fd0
cp * /fd0
	(finishes almost instantly)
umount /fd0
	(pauses for ~30 secs, then the prompt reappears. I remove disc)

sync()s are generated every 30 seconds by a script called bdflush to prevent 
data staying in the cache and never getting flushed to disc.

This is Good Behaviour for a multitasking system like Linux. For a simple 
system like DOS, the current behaviour (much shorter delay, sync on command 
prompt) is Good Behaviour. With NWCACHE's habit of lending memory out, you 
don't waste memory --- so why fix it if it ain't broken?

BTW, does anyone know how to get NWCACHE to accept more than 7200-odd kB of 
memory for a cache? I've got 16MB and standard DOS hardly uses any of the 
extended. I've tried changing the numbers in the invokation but it doesn't 
help.

-- 
------------------- http://www-hons-cs.cs.st-and.ac.uk/~dg --------------------
   If you're up against someone more intelligent than you are, do something
    totally insane and let him think himself to death.  --- Pyanfar Chanur
---------------- Sun-Earther David Daton Given of Lochcarron ------------------