Re: Lockup 2.1.6* => kmalloc/slab ???

Alan Cox (alan@lxorguk.ukuu.org.uk)
Sat, 8 Nov 1997 23:09:13 +0000 (GMT)


> > This gives page-colouring (and a few other performance improvements)
> > coupled with a weak fragmentation control. I'm calling the control weak,
> > as I've out ripped all the heavy control stuff I was doing (well, was
> > doing this morning). It will also speed up most CPU/memory intensive
> > tasks.
> Does this fragmentation control actually defragment if needed? Not being
> able to allocate memory while enough free pages are present (though
> fragmented) looks as a deficiency to me. What about next points? Forgive me
>it these are absolute nonsens or already implented.

On a 32Mbyte box running a fair bit of NFS page colouring causes enough
fragmentation that the NFS performance goes to pieces, and on non NFS I can't
measure any difference for normal use.

Im sure page colouring makes sense on a box with 512Mb of RAM and with fragmentation
control, but not on anything that much smaller. This is also an SMP box with
low memory bandwidths - the sort that might gain most