Profiling with Instruments
Instruments can be used for memory profiling and for statistical profiling.
- Select "Time Profiler" from the "Choose a profiling template for:" dialog.
- In the top left, next to the record and pause button, there will be a "[machine name] > All Processes". Click "All Processes" and select "firefox" from the "Running Applications" section.
- Click the record button (red circle in top left)
- Wait for the amount of time that you want to profile
- Click the stop button
How do we monitor performance counters (cache miss etc.)? Instruments has a "Counters" instrument that can do this.
Instruments will record a call stack at each allocation point. The call tree view can be quite helpful here. Switch from "Statistics". This
malloc profiling is done using the
malloc_logger infrastructure (similar to
MallocStackLogging). Currently this means you need to build with jemalloc disabled (
ac_add_options --disable-jemalloc). You also need the fix to Bug 719427
DTPerformanceSession api can be used to control profiling from applications like the old CHUD API we use in Shark builds. Bug 667036
System Trace might be useful.