Struct perf_event::CountAndTime

#[repr(C)]
pub struct CountAndTime {
    pub count: u64,
    pub time_enabled: u64,
    pub time_running: u64,
}

The value of a counter, along with timesharing data.

Some counters are implemented in hardware, and the processor can run only a fixed number of them at a time. If more counters are requested than the hardware can support, the kernel timeshares them on the hardware.

This struct holds the value of a counter, together with the time it was enabled, and the proportion of that for which it was actually running.

Fields

count: u64

The counter value.

The meaning of this field depends on how the counter was configured when it was built; see [‘Builder’].

time_enabled: u64

How long this counter was enabled by the program, in nanoseconds.

time_running: u64

How long the kernel actually ran this counter, in nanoseconds.

If time_enabled == time_running, then the counter ran for the entire period it was enabled, without interruption. Otherwise, the counter shared the underlying hardware with others, and you should prorate its value accordingly.