agressive swap-out?

Mikael Abrahamsson (swmike@uplift.sparta.lu.se)
Sun, 20 Apr 1997 19:10:32 +0200 (MET DST)


I remember back year ago (or more) when I used to run kernel 1.2.13. I
remember I complained to this list that the kernel was too agressive
swapping out memory currently not used in order to create disk cache/other
buffers.

Now with 2.0.30 (rather pre-2.0.30-2) I have for some time thought of it
the other way around, that perhaps it would be nice for the kernel to be a
bit *more* agressive to swap out unused memory to get more buffers.

After a few hours of uptime on my machine with my desktop properly set up
with 20 xterms, a couple of netscape windows etc, I still dont see
anything swapped out of my 112M machine. I had a friend write a program
that allocated an amount of memory specified in the command line, then
writes thru the memory are a couple of time etc, so that the system really
needs to swap out other stuff to get this program to fit. I usually use 64
or 80 meg size of this memory area.

This usually means I have like 25 megs on the swap after I run this
program, that is never needed anymore. I think this is X buffers etc.
The machine runs much more comfortable after this, with disk cache being
in the range of 30-50 megs instead of the 10-25 megs I had before the
operation.

Are there any tunings I can use to set the agressiveness of the kernel
when it comes to swapping out memory to increase buffers?

-----
Mikael Abrahamsson email: swmike@df.lth.se