the option irq-info which is on by default that adds this information: # tracer: nop # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | -0 [000] d..2 49.309305: cpuidle_get_driver <-cpuidle_idle_call -0 [000] d..2 49.309307: mwait_idle <-cpu_idle -0 [000] d..2 49.309309: need_resched <-mwait_idle -0 [000] d..2 49.309310: test_ti_thread_flag <-need_resched -0 [000] d..2 49.309312: trace_power_start.constprop.13 <-mwait_idle -0 [000] d..2 49.309313: trace_cpu_idle <-mwait_idle -0 [000] d..2 49.309315: need_resched <-mwait_idle If a user wants the old format, they can disable the 'irq-info' option: # tracer: nop # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | -0 [000] 49.309305: cpuidle_get_driver <-cpuidle_idle_call -0 [000] 49.309307: mwait_idle <-cpu_idle -0 [000] 49.309309: need_resched <-mwait_idle -0 [000] 49.309310: test_ti_thread_flag <-need_resched -0 [000] 49.309312: trace_power_start.constprop.13 <-mwait_idle -0 [000] 49.309313: trace_cpu_idle <-mwait_idle -0 [000] 49.309315: need_resched <-mwait_idle Requested-by: Thomas Gleixner Signed-off-by: Steven Rostedt ,ex