Suppose we wish, as described at the end of Example 16.36, to accurately attribute sampled time to the various contexts in which a subroutine is called. Perhaps the most straightforward approach would...

Suppose we wish, as described at the end of Example 16.36, to accurately attribute sampled time to the various contexts in which a subroutine is called. Perhaps the most straightforward approach would be to log not only the current PC but also the stack backtrace—the contents of the dynamic chain—on every timer interrupt. Unfortunately, this can dramatically increase profiling overhead. Suggest an equivalent but cheaper implementation.