OpenCL Reports

If you mark the OpenCL checkbox in the Trace Settings area of the Activity document, the NVIDIA Nsight analysis tool produces reports that include OpenCL-specific trace data.

OpenCL Summary

The OpenCL Summary appears in the middle of the top-level Summary Report. It shows a summary of the OpenCL-related information collected in the session. The summary displays information about API calls per context and per queue. Contexts with more than one queue also contain a Summary row, which shows the aggregated statistics for all queues in the parent context.

Column Label Description

Contexts Lists the contexts that were created during the capture. Each context appears on its own row, along with the corresponding data related to that context.

Queues Lists the queues created for each context. If there is more than one queue for a context

Devices The OpenCL device used for each queue.

API Calls The number of API calls, errors, threads, and time spent per queue.

Kernels The number, % Time, % Concurrent for all kernels per queue

Memory The number, bytes transferred, % Time, and % concurrent for all OpenCL memory transfers per queue.

OpenCL API Call Summary

Column Label	Description
Contexts	Lists the contexts that were created during the capture. Each context appears on its own row, along with the corresponding data related to that context.
Queues	Lists the queues created for each context. If there is more than one queue for a context
Devices	The OpenCL device used for each queue.
API Calls	The number of API calls, errors, threads, and time spent per queue.
Kernels	The number, % Time, % Concurrent for all kernels per queue
Memory	The number, bytes transferred, % Time, and % concurrent for all OpenCL memory transfers per queue.

The API Call Summary lists statistics of calls made to the OpenCL API, including the number of times the API call was called, the percentage of time of the overall capture time that the API call took, the number of errors returned, and statistics on the elapsed time each API call took while executing.

OpenCL Platforms

The OpenCL Platforms report shows data on the OpenCL platforms on the machine on which the OpenCL trace was run. The data captured and shown in this view is captured using the standard clGetPlatformInfo and clGetPlatformIDs API calls.

OpenCL Program Builds

The OpenCL Program Builds report shows every OpenCL Program built by your program using the clBuildProgram API call. Using this report, you can see data on all program builds that occurred in your program's execution, and can view the source and assembly for each program.

Column Label Description

Program ID
The id of the program being built.

Actions
There are two buttons available under Actions: The first will display the source of this OpenCL program, and the second will display the assembly of this OpenCL program.

Device ID
The id of the OpenCL device used in the builds.

API Call ID
The Call ID of the clBuildProgram API call.

Time (µs)
The amount of time elapsed during the clBuildProgram API call.

Options
Any options passed into the clBuildProgram API call

Status
The returned status of the clBuildProgram API call

Log Any log output from this clBuildProgram API call

Context ID The OpenCL id used for this API call

Process ID The CPU process ID for this API call

OpenCL Kernel Launch Commands

Column Label	Description
Program ID	The id of the program being built.
Actions	There are two buttons available under Actions: The first will display the source of this OpenCL program, and the second will display the assembly of this OpenCL program.
Device ID	The id of the OpenCL device used in the builds.
API Call ID	The Call ID of the clBuildProgram API call.
Time (µs)	The amount of time elapsed during the clBuildProgram API call.
Options	Any options passed into the clBuildProgram API call
Status	The returned status of the clBuildProgram API call
Log	Any log output from this clBuildProgram API call
Context ID	The OpenCL id used for this API call
Process ID	The CPU process ID for this API call

The OpenCL Kernel Launch Commands report shows every OpenCL kernel that was launched during your program's execution. Each row shows the time of execution and work size data for each launch.

OpenCL Memory Copy Commands

The OpenCL Memory Copy Commands report shows every copy command executed in your program. Memory copy commands can be performance limiting, especially the copy command results in a transfer of data across the PCI-e bus from your CPU to your GPU or from your GPU to your CPU.