I tried build.sh on my SS1+ with around 20040418 kernel,
but system CPU time during compilation seems much higher:

---
load averages:  1.19,  1.18,  1.17                                     18:37:49
49 processes:  1 runnable, 47 sleeping, 1 on processor
CPU states:  9.1% user,  0.0% nice, 90.1% system,  0.9% interrupt,  0.0% idle
Memory: 28M Act, 14M Inact, 1912K Wired, 6444K Exec, 18M File, 488K Free
Swap: 80M Total, 19M Used, 61M Free

  PID USERNAME PRI NICE   SIZE   RES STATE      TIME   WCPU    CPU COMMAND
16589 root      54    0  4748K   15M RUN       83:07 92.77% 92.77% cc1
 3547 root      32    0   248K 1080K CPU        0:00 14.36%  2.00% top
  143 root       2    0   148K  616K select    12:25  1.03%  1.03% ypbind
11242 tsutsui    2    0   472K 1856K select     0:19  0.98%  0.98% sshd
 :
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I think old sparc kernels (~1.6W) had the similar problem
and then it was fixed:
http://mail-index.netbsd.org/port-sparc/2003/07/31/0000.html
http://mail-index.netbsd.org/port-sparc/2003/08/03/0000.html
but now it returns again?
---
Izumi Tsutsui
tsutsui@ceres.dti.ne.jp