Apache 2.2 used to provide access to SVN consumes a lot of memory
Solution 1:
APR can slowly leak memory because of the way APR pools fragment available RAM over time. If you can configure the max requests per child limit in Apache lower so the tasks will restart sooner that should mitigate the problem to an extent. The MaxMemFree directive may also be helpful, but be warned that the mailing list post suggests it doesn't work as advertised.