KCacheGrind offers numerous ways to peer into your application's performance, among them the ability to tie execution times directly to the source code. Figure 3 presents KCacheGrind's annotated view of the profiled source code, prepending the execution time to each respective line.
Another interesting way to peer into your application's execution cycle is via KCacheGrind's Call Graph feature, an example of which is found in Figure 4. This graph not only traces the execution flow, but also associates call frequencies and the amount of total execution time required by each step in the cycle.
Xdebug and KCacheGrind offer invaluable insight into application performance, not only presenting a comprehensive breakdown of the entire cycle's execution time but also providing the ability to visually trace the execution path using a variety of tabular and flowchart-based views. Be sure to check out the following resources for more information about optimizing your PHP applications: