this is how much memory kernel consumes on mine machine:

    4 DK   0:07.00  20 127      0     0 19524   -    0  0.0 14.9
[pagedaemon]

now i have started few programs, and compiler.

under similar load old 1.5.2 kernel used no more than 12MB (with similar
kernel config, about 1.8MB kernel binary).

BUFPAGES were 4MB with 1.5.2 and 2MB now (as it holds only metadata).

vmstat -m shows

vnodepl      152    10000    0        0   385     0   385   385     0
inf    0
ncachepl      72    10000    0        0   179     0   179   179     0
inf    0
ffsinopl     260   104022    0    94027   817   150   667   667     0
inf    0

as major consumers.

is it an effect of

kern.maxvnodes=10000
?

if so - old kernel were used with same settings