Tomcat performance degrades when moved to its own subsystem. Any insights?

We just had a report, from one of our customers, of a case in which moving a Tomcat server into its own subsystem caused performance to degrade instead of improve.

On starting the server in the subsystem, CPU utilization jumped to over 30%, and it evidently was balky in serving the sign-on page for our webapp. On returning the Tomcat server to its previous subsystem, everything returned to what it was before.

From the instructions we gave the customer:

CRTSBSD SBSD(<name>) POOLS((1 *BASE) (2 <size of private memory pool in
kilobytes> 200))

The size should be the same as the maximum heap specified on the STRTOMCAT,
or a bit larger, but remember, this is in kilobytes, while the STRTOMCAT
command expects megabytes, so multiply by 1024. The activity level of 200
should allow for plenty of threads, but it can be increased as needed.

At this time, we don't know how big of a private memory pool they actually gave the subsystem.

--
JHHL