You are working on a GNU/Linux system with at least a 2.6.16 Kernel and are tired of getting ‘PermGen Space’ errors with Eclipse, whatever value you choose for -Xms, -Xmx and -XX:MaxPermSize settings ?

An explanation could be that Eclipse fails to claim memory that is not really used by the system, but simply cached.

A solution is to flush cache before launching Eclipse by issuing the following command (as root) in a terminal :

sync; echo 3 > /proc/sys/vm/drop_caches

Hope it helps