Re: How to limit amount of virtual memory used for files (was: Re: Tuning ZFS memory usage on NetBSD - call for advice)

[Lloyd Parkes <lloyd%must-have-coffee.gen.nz@localhost>]

I wrote a quick and dirty program to trigger vast amounts of File memory 
usage only to remind myself of something important.

Having File memory use all available RAM with only scraps left is not a 
problem by itself. The memory is there to be used and it is getting 
used. I used to have to explain this as part of my $dayjob, so it's a 
bit embarrassing that I forgot it.

What is a problem is if that memory isn't freed up for other uses when 
necessary. Håvard's email about his G4 Mac Mini is an excellent example 
of a problem. A problem I have experienced in the past was a program 
failing with out of memory errors while processing 128MB of data on a 
system with 256MB of RAM. A problem doesn't have to be a crash. It could 
simply be unnecessary swap being used leading to terrible performance.

Can we put together a catalogue of clearly defined problems so that we 
can reproduce them and investigate further? While Håvard appears to have 
solved his problem, I'm pretty sure I have an unused G4 Mac Mini of my 
own that I can try and reproduce his problem on.

Cheers,
Lloyd