- Add a ptrace interface to allow collecting an execution trace
- of the traced task.
- This collects control flow changes in a (cyclic) buffer and allows
- debuggers to fill in the gaps and show an execution trace of the debuggee.
+ This adds a ptrace interface to the hardware's branch trace store.
+
+ Debuggers may use it to collect an execution trace of the debugged
+ application in order to answer the question 'how did I get here?'.
+ Debuggers may trace user mode as well as kernel mode.
+
+ Say Y unless there is no application development on this machine
+ and you want to save a small amount of code size.