Function s_memrealtime 

pub fn s_memrealtime() -> u64

🔬This is a nightly-only experimental API. (stdarch_amdgpu #149988)

Available on target_arch=amdgpu only.

Measures time based on a fixed frequency.

Provides a real-time clock counter that runs at constant speed (typically 100 MHz) independent of ALU clock speeds. The clock is consistent across the chip, so can be used for measuring between different wavefronts.