Tex related metrics

Is there any explanation about the following metrics?
tex_fu_utilization -> smsp__inst_executed_pipe_tex.avg.pct_of_peak_sustained_active
tex_sm_tex_utilization -> l1tex__f_tex2sm_cycles_active.avg.pct_of_peak_sustained_elapsed
tex_sm_utilization -> sm__mio2rf_writeback_active.avg.pct_of_peak_sustained_elapsed
tex_utilization -> NOT AVAILABLE

For Nsight Compute metrics, you can see their descriptions from --query-metrics on the command line. After collection, the description is also shown as a tool tip in the UI. The descriptions of metric suffixes like pct_of_peak_sustained_elapsed can be found here: https://docs.nvidia.com/cupti/Cupti/r_main.html#r_host_derived_metrics_api