Hi there,
When I am trying to use ftrace to measure cpuidle latency, I find that the timestamp is always ending with 0000, like below.
bash-2.05b# head trace
# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
<idle>-0 [000] 79.530000: cpu_idle: state=0 cpu_id=0
<idle>-0 [000] 79.530000: cpu_idle: state=4294967295 cpu_id=0 <idle>-0 [000] 79.530000: cpu_idle: state=0 cpu_id=0
<idle>-0 [000] 79.530000: cpu_idle: state=4294967295 cpu_id=0 <idle>-0 [000] 79.530000: cpu_idle: state=0 cpu_id=0
<idle>-0 [000] 79.530000: cpu_idle: state=4294967295 cpu_id=0
But it is supposed to be more accurate like:
<idle>-0 [000] 270.396210: cpu_idle: state=4294967295 cpu_id=0 <idle>-0 [000] 270.422424: cpu_idle: state=0 cpu_id=0 <idle>-0 [000] 270.427124: cpu_idle: state=4294967295 cpu_id=0 <idle>-0 [000] 270.427185: cpu_idle: state=2 cpu_id=0
Did I miss something in kernel configuration or some certain features?
Thanks Yong