Intel® FPGA SDK for OpenCL™ Pro Edition: Best Practices Guide

ID 683521
Date 10/04/2021
Public

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5.5.1. Profiling Autorun Kernels

Autorun kernel profiling feature allows you to profile autorun kernels.

Kernels that are marked with the autorun attribute are referred to as autorun kernels. An autorun kernel starts executing without being created and launched by the host, so it runs before the kernels that are explicitly enqueued, and restarts automatically on completion. For more information about the autorun attribute, refer to Omit Communication Hardware between the Host and the Kernel topic.

Attention: Autorun kernel profiling feature does not allow profiling individual kernels. The data for all autorun kernels in the design are read in a single attempt.

When temporal profiling is enabled, all autorun kernels in the design are profiled at the specified temporal period.

When temporal profiling is disabled, by default, the Profiler does not provide any profiling information since autorun kernels never finish. You can inform the Profiler when to profile by calling the host library function clGetProfileDataDeviceIntelFPGA to capture the autorun profiler data. This call can be made at any point during execution. For more about profiling using host API calls, refer to Profiling Enqueued and Autorun Kernels.

Note: The host API call works whether temporal is enabled or not, but it is required to get autorun profiling data when temporal is disabled.