vm issues (2)

[Dejan Muhamedagic <dejan@hello-penguin.com>]

Hello,

The new kernel 2.4.21-pre4aa3 is running now, but the box behaves
similarly.  It still swaps quite a lot and much more than the rmap
vm.  Both servers are under the same load.

One difference is the amount of free memory:

 r  b  w   swpd   free   buff  cache  si  so    bi    bo   in cs  us  sy  id
aa:
 0  7  0 5773620 202416 118076 2069716 5330 746  5330   766 4845 5597  12  14  74
rmap:
 0  0  0 3498044  13572   4144 4754596  74   0    75     6  642 598   5   3  92

The aa kernel keeps ~200MB out of 6GB of memory unused.  I'm not
sure, but if we could reduce it perhaps there would be much less
swapping.  Is there a way to achieve this?

Another notable difference between the two vm versions is that the
rmap vm maintains about 80% of memory on the active list and the
aa vm much less: between 4% and 12%.  The rmap vm must use more
CPU, but these servers have a lot of processing power so it is not
noticeable.

Cheers,

Dejan