Run-Time Event API Performance Counters - 2021.2 English

Versal ACAP AI Engine Programming Environment User Guide (UG1076)

Document ID
UG1076
ft:locale
English (United States)
Release Date
2021-12-17
Version
2021.2 English
Run-time event APIs use the performance counters in the AI Engine-PL interface tiles and the AI Engine-NoC interface tiles. There are two performance counters in each column of the interface tiles. This section lists the number of performance counter - used by each run-time event API. If the total number of performance counters used exceeds the availability of performance counters in a column of the interface tile, the API that cannot acquire the performance counter fails with the following error message in AI Engine simulator.
[AIE WARNING]: Unable to request resources. RscType: 0
ERROR: event::start_profiling: Failed to request performance counter resources.
For hardware emulation or hardware flows, the following error message is used.
[XRT] ERROR: ERROR: event::start_profiling: Failed to request performance counter resources.: Resource temporarily unavailable
Table 1. Run-Time Event API Performance Counters
Run-time Event Enumeration Number of Performance Counters
event::io_total_stream_running_to_idle_cycles 1
event::io_stream_start_to_bytes_transferred_cycles 2
event::io_stream_start_difference_cycles 1 for input port, 1 for output port
event::io_stream_running_event_count 1
Note: Performance counters are released after event::stop_profiling. The run-time event API can acquire the same performance counters again after they are released.
Note: When multiple graph ports are mapped into the same interface tile, if run-time event APIs are used on these ports, they will compete for the performance counters in the same interface tile.