Subject: Re: IO buffer cache allocation
To: David Gilbert <pci!jaywon!>
From: Luke Mewburn <>
List: current-users
Date: 01/20/1996 15:18:26
David Gilbert writes:
> 	While I'm on the rampage of new kernel config lines, there are
> two things that I'd like to know how to change.

> 	Currently, I have 24 meg of memory in my Sun4/260.  While I
> can accept that some machines with smaller amouns of memory may not
> want it --- I was always of the school that 10% of memory was a good
> number for the buffer cache in lieu of any better information.

> 	I would like a 10% buffer cache for my box.  The default
> sseems to be along the lines of 5%.

I recently submitted a PR that modified machdep.c on the i386 port to
allow you to do
		options BUFCACHE=xxx
where xxx is a % of physmem to devote to bufcache. With a 16MB machine
I set it to 15% ;-)

The code would be trivial to incorporate into all other ports.
Hopefully the various port masters incorporate it, because until a
unified buffer cache is implemented (which obviates the need for this
option), it's a useful option.

Luke Mewburn <>
"This is the central trick of the censor: to exaggerate the importance of the
 challenging speech, to suppress it, and to deny the suppression."
        -- `Guilty Secrets; Free Speech & Defamation in Australia', Roger Pullan