Solaris 10 update 8 upgrade slow mysql performance

[uuperl]

Current Configuration:

- T5120 running Solaris 10 update 4 8/7 with LDOM 1.3
- T5120 has 4 146G disks and has raid 1 (1 & 2, 3 & 4)
- Primary has 4 VCPUs and 4G memory
- Primary control has 8 ldoms, 2nd ldom is database server
- database server has two virtual disks, 1st for OS and 2nd for database
- 2nd LDOM (database server) has 12 VCPUs and 8G memory
- MySQL server 5.5.8 Community Server (GPL), OS solaris 10 update 8
- MySQL server virtual disks are on disk 3 & 4 which are raid one

primray ldm configruation:

ldm add-vdsdev /ldomdb/ldom2 vol2@primary-vds0
ldm add-vdsdev /ldomdb/ldom2-db vol2a@primary-vds0

ldm add-vdisk vdisk2 vol2@primary-vds0 ldom2
ldm add-vdisk vdisk2a vol2a@primary-vds0 ldom2

My problem is once I upgrade the primary control ldom to solaris 10 update 8
then mysql store procedure performance reduced:

old: Primary Control Solaris 10 update 4 8/7, store procedure takes only 0.87 secs to finish
new: Primary Control solaris 10 update 8 10/09, store procedure takes about 45 secs to finish

Firmware on the system are current

Seems to me some paramaters on update 8 has changed, but I don't know how to find it out.
If any one know or how to trouble shoot this issue please let me know
Thanks for you help!