To run a memory-access debugging utility (such as an instrumented malloc library, or Purify, DEC^WCompaq^WHP's Third Degree, Insure++, ElectricFence, or anything similar), with the aim of identifying memory usage patterns of the program.
Such memory profiling techniques work in "Space", and are distinct from the more common execution profiling techniques, which work in "Time". The most primitive (but effective!) way to measure execution time on UN*Xoid systems is to use
/usr/bin/time (or a variant), which reports wall, user and system time. Thus, to profile in space is to untime the program.
Unguiform intercalated programs often exhibit poor performance, and are badly in need of both timing and untiming.