On Fri, 27 Aug 2004, Geoff Wing wrote:

> Wouter Klouwen <dublet@dublet.org> typed:
> : I'm running a -current kernel on my laptop, which has 256MB of internal
> : memory, and a quite slow HDD. The filecache is usually ~170MB, this is
> : really way too much,
>
> Umm, "too much"?  What do you expect your memory to be doing?  If you have
> free memory after hours of use then you've wasted money buying stuff you're
> not using.  It's great that it's using the memory you've paid for.  If you
> have a complaint then it can only be because it didn't prioritise memory
> usage properly.  Since you haven't indicated that that was the problem
> you seem to have not quite understood what benefits of RAM are.  Or maybe
> just haven't indicated that you've understood them.

I can't speak for Wouter, but in my case, the system *is* doing things 
wrong.
It's not a laptop, but a stationary machine, with rather fast SCSI. And it 
acts both as my NFS server, and as my interfactive plaything.
The current "hit" for me came because I have another machine that was 
building X, which had xsrc nfs-mounted from this server. At the same time 
I was reading mail with netscape. The file cache grabs a lot of memory, 
and forces a large number of pagefaults in Netscape. The result is that a 
number of other programs, also needing a bit more memory also get hit. 
Thus, my machine got about 90% idle, a load of about 4, and about 200 
pageing in/out ops per second.

This is clearly not optimal. Bollocks the file cache buffers, let my 
programs stay in memory instead. Much better performance. Then the CPU can 
do some work as well, and the disk can be bothered with the NFS requests, 
instead of both getting the NFS traffic *and* my pagefaults to the disk, 
and the CPU just sitting there wasting cycles.

It's *obviously* not a good balance in there, for atleast my useage.

I *don't* have too much ram, I obviously have too little, and at that 
situation, things aren't really fun anymore. NetBSD used to be much faster 
in the past for me. (And no, the answer isn't always "buy more memory".)

 	Johnny

Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt@update.uu.se           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol