i tried to do (possibly stupid thing). instead of

                uvmexp.inactarg = (uvmexp.active + uvmexp.inactive) / 3;

in uvm_pdaemon.c

i did

                uvmexp.inactarg = (uvmexp.active + uvmexp.inactive) / 20;


20 isn't anything special, just much more than 3. I have 128MB RAM.

with filemin,filemax set to 5,30 with sysctl machine is now much more
usable than before under high I/O load and programs are not so much wiped
out by buffer caches. difference are huge.