Hello Anderson,
The problem is not about the resources, check if your local garbage collector is working properly for example, in the meantime I recommend you to clear the portal cache as soon as possible, here there are some options:
How to clear the SAP Portal cache
also follow Vadim's advice and contact your basis team to apply a linux command to clear the cache from the console, finally... may be you will need restart this portal's instance.
Saludos cordiales !! Adalid.