High run queue and low cpu usage on IBM AIX 6.1 server after Oracle 11g upgrade

Today we upgraded our Oracle 10.2.0.4 databases to v11.2.0.2.3. After the upgrade we notice that the run queue is very high and cpu is 70-80% idle. Nothing is being run on any databases on the server right now. What could be the possible reasons for this? Any thoughts?

vmstat 1 6

System configuration: lcpu=12 mem=102656MB

kthr    memory              page              faults        cpu
----- ----------- ------------------------ ------------ -----------
 r  b   avm   fre  re  pi  po  fr   sr  cy  in   sy  cs us sy id wa
23  0 22987945 2859301   0   0   0   0    0   0 117 14803 18789 18  4 78  0
27  0 22986580 2860666   0   0   0   0    0   0 110 19431 18774 21  5 75  0
16  0 22988108 2859138   0   0   0   0    0   0 132 17319 19909 17  4 79  0
18  0 22993998 2853248   0   0   0   0    0   0 119 21111 18691 22  4 74  0
22  0 22994087 2853159   0   0   0   0    0   0  89 22597 18782 20  4 76  0
23  0 22994087 2853159   0   0   0   0    0   0  90 15440 19226 14  3 82  1

Tejal