Re: >64M RAM, 256kB cache.. will I have problems?

Pavel Machek (
Sun, 14 Dec 1997 12:11:42 +0100


> > I would really like to make linux work nicely on machines with
> > dual-speed ram. I have 20Meg and only 16Meg are cacheable. When top
> > 4Meg are used, machine goes to speed about speed of 386... I made some
> > patch but it is not too good. (Mail me for it).
> Please take a look at the drivers/block/z2ram.c. Some Amigas have fast 32-bit
> memory on the motherboard, and slow 16-bit memory on Zorro II expansion boards.
> The z2ram device creates a block device for the slow RAM, so you can use it as
> a fast swap partition.

Hmm, nice, but does not fit my needs, anyway.

Why: I have 16Meg, which is enough for normal usage, but there's not
too much room for disk buffers. That ramdisk would be unused for most
of the time, but I would not have disk buffers.

Linux is pretty stupid: If you have 64Meg of ram, and applications
which take 60Meg of ram but do not use it too much and access disk a
lot, Linux will happily leave it this way. It would be much more
better (in this particular case) to throw apps into swap, and use
freed memory as cache.

(It might be also nice to use swap as disk buffers. Would solve my
problem, too, and people installing redhat from floppy on 8Meg machine
would thank you ;-).


Who was looking for mm things to hack?

I'm really 	   Pavel
Look at ;-).