I did a rapid check over several cycle (initialization, mining, change of block etc...) I don't see any memory leak. The amount of swap and RAM vary along a cycle however it is always freed before a new initialization. The only case which could cause subtantial increase of RAM would be running at very low difficulty where you would be solving solution faster than you send them to the pool (but again, once it is sent to the pool, the memory is freed). If it is the case, you should probably increase the difficulty