When starting to process an event from the main loop, Firefox will grab the current time (|start|). Each time the profiler takes a sample, it also reads the current time (|curr|), and adjusts the weight of the sample by f(curr-start) Likely we will want f to be discontinuous. Up to a tolerated latency (100 ms?), it should return a weight of 1. After that, the samples should probably be weighted by a function that grows exponentially to match the user's frustration.

(In reply to comment #0) > Likely we will want f to be discontinuous. s/discontinuous/non-differentiable/. Been a while since high school calculus.

Cleopatra UI does this, in effect.