Profiling

GREASE includes functionality for profiling its performance. To generate a profiling report, pass --profile-to <DIR> to GREASE. This will generate a <DIR>/profile.html file that can be viewed in a web browser. The data that this HTML file presents will be periodically regenerated as GREASE runs on the program. A typical example looks like:

The profiling report presents a hierarchical view of the functions that are invoked during the simulation of a program. The x-axis represents the time, and the y-axis shows the call stack depth, counting from zero at the bottom. Each stack frame is given a score based on some simulator heuristics (the time spent simulating it, its number of allocations, its numbers of merges, etc.). Generally speaking, the higher the score, the more likely it is to be a performance bottleneck.