Solaris 10 Memory utilization

We have a T2000 server with 16 GB memory running 4 whole-root zones. The server is hitting 85% - 90% memory consumption frequently eventhou the memory consumed by all 4 zones is only 10GB (prstat -Z). We have limited ZFS arc to 2 GB and below is output of "::memstat".

root@reg-xxx7# echo "::memstat" | mdb -k
Page Summary                Pages                MB  %Tot
------------     ----------------  ----------------  ----
Kernel                     418383              3268   20%
ZFS File Data              117475               917    6%
Anon                      1011401              7901   50%
Exec and libs               27062               211    1%
Page cache                  37271               291    2%
Free (cachelist)            50817               397    2%
Free (freelist)            379626              2965   19%

Total                     2042035             15953
Physical                  2036653             15911

Could someone explain why kernel is taking 3GB and options to restrict it.