[vinkelhake]

It's the size of the binary. I don't understand what you mean by proportional size.

If we add more functionality to the hello world program, the dynamically linked version should increase in size slower than the statically linked.

[mdwrigh2]

The point of proportional size is to account for the size of glibc, which has to be on disk and in memory and so incurs a cost that isn't accounted for by just looking at the size of the binaries that link against it, by dividing glibc's size by the number of applications that use it.

When examining memory usage on Linux systems, one of the common measurement metrics is the Proportional Set Size (PSS), which essentially is what I was asking about (but for on-disk size, rather than just in-memory): http://lwn.net/Articles/230975/