ktime_get_real_offset和ktime_get_real_ts64

ktime_get_real_offset is a function in the Linux kernel that returns the offset between the system's monotonic clock and the real-time clock. The monotonic clock is a clock that is always moving forward, regardless of any changes to the system's time settings, while the real-time clock represents the actual time of day.

ktime_get_real_ts64 is another function in the Linux kernel that returns the current real-time timestamp as a 64-bit value. It provides the number of nanoseconds elapsed since the system's boot time, without taking into account any adjustments made to the system's time settings.

Both of these functions are used in the Linux kernel to deal with time-related operations and provide accurate timestamps for various purposes