Difference between System.map and /proc/kallsyms

Hi.. After reading Documentation on System.map, i understood that , whenever an oops happens the following addresses will be converted to its function name by klogd daemon using System.map. Now when we have /proc/kallsyms which stores the symbol table in the kernel image itself.Then what is the need of System.map file??Is any process or daemon still using it?? Regards, Md.Jamal