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