It looks like permgen collection happens only at a full GC.
Full GC is triggered when oldgen is full.
As result it is easy to get OOM in PermGen even when no live data are left.

It would be helpful to trigger a permgen collection when we run out of permgen.
Synopsys changed from: "Permgen collection needs to be triggered when we are out of permgen."
to: "Class unloading not happening promptly enough, causing OOM in perm gen"

Note that perm gen collection does happen at a full gc which is triggered
when we are out of space in the perm gen.
In this case, something else may be preventing the reclamation of space in
the perm gen, possibly a result of slow finalization (conjecture). See
comments section.
Please look at the CR 6293787 and close this as a duplicate if you agree it is
the same problem.
Not clear if SQE is OK with deferring this bug? Is this bug deferred to 7pool or 8? If SQE is OK with deferring, please add a comment for this bug and add RC7-defer-approved keyword to defer this bug.