Configure pCluster | Tactic 4: identifying by swprofiler
Set Xk and Xp values in WebSphere Administration Console
The figure below is an example of setting Xk and Xp, which specifies -Xk22000 -Xp64k,16k in generic JVM arguments. If the problem persists, experiment with higher initial pCluster settings and overflow pCluster sizes. After this tuning, if there are fragmentations left, you can suspect large object problems.