Using Buffer Args Sample

Purpose

To learn how to pass sycl buffers as arguments

Reference

This sample was modified after the oneAPI Samples Catalog. Specifically the DirectProgramming->DenseLinearAlgebra->simple-add example.

This readme is largely the same as the above oneAPI example.

Prerequisites

Warning: Unbuntu should work, but it was not tested. Only Windows 10 with vscode was used. The USM example is also not completed.

Optimized for	Description
OS	Ubuntu* 18.04 Windows* 10 (this sample not tried on Ubuntu)
Software	Intel® oneAPI DPC++/C++ Compiler

Key Implementation Details

This sample provides examples of both buffers and USM implementations (not done) for simple side-by-side comparison.

• USM requires an explicit wait for the asynchronous kernel's computation to complete.
• Buffers, at the time they go out of scope, bring main memory in sync with device memory implicitly. The explicit wait on the event is not required as a result.

Note: For comprehensive information about oneAPI programming, see the Intel® oneAPI Programming Guide. (Use search or the table of contents to find relevant information quickly.

Set Environment Variables

When working with the command-line interface (CLI), you should configure the oneAPI toolkits using environment variables. Set up your CLI environment by sourcing the setvars script every time you open a new terminal window. This practice ensures that your compiler, libraries, and tools are ready for development.

Build the Program

Note: If you have not already done so, set up your CLI environment by sourcing the setvars script in the root of your oneAPI installation.

Linux*: (warning: this sample was not tried on Ubuntu)

• For system wide installations: . /opt/intel/oneapi/setvars.sh
• For private installations: . ~/intel/oneapi/setvars.sh
• For non-POSIX shells, like csh, use the following command: bash -c 'source <install-dir>/setvars.sh ; exec csh'

Windows*:

• C:\Program Files(x86)\Intel\oneAPI\setvars.bat
• Windows PowerShell*, use the following command: cmd.exe "/K" '"C:\Program Files (x86)\Intel\oneAPI\setvars.bat" && powershell'

For more information on configuring environment variables, see Use the setvars Script with Linux* or macOS* or Use the setvars Script with Windows*.

Using Visual Studio Code* (VS Code) (Optional)

You can use Visual Studio Code* (VS Code) extensions to set your environment, create launch configurations, and browse and download samples.

The basic steps to build and run a sample using VS Code include:

1. Configure the oneAPI environment with the extension Environment Configurator for Intel® oneAPI Toolkits.
2. Download a sample using the extension Code Sample Browser for Intel® oneAPI Toolkits.
3. Open a terminal in VS Code (Terminal > New Terminal).
4. Run the sample in the VS Code terminal using the instructions below.

To learn more about the extensions and how to configure the oneAPI environment, see the Using Visual Studio Code with Intel® oneAPI Toolkits User Guide.

On Linux*

Configure the build system

1. Change to the sample directory.

2. Configure the project to use the buffer-based implementation.

   mkdir build
   cd build
   cmake ..
   

   or

   Configure the project to use the Unified Shared Memory (USM) based implementation.

   mkdir build
   cd build
   cmake .. -DUSM=1
   

   Note: When building for FPGAs, the default FPGA family will be used (Intel® Agilex® 7). You can change the default target by using the command:

   cmake .. -DFPGA_DEVICE=<FPGA device family or FPGA part number>
   

   Alternatively, you can target an explicit FPGA board variant and BSP by using the following command:

   cmake .. -DFPGA_DEVICE=<board-support-package>:<board-variant>
   

   You will only be able to run an executable on the FPGA if you specified a BSP.

Build for CPU and GPU

1. Build the program.

   make cpu-gpu
   

2. Clean the program. (Optional)

   make clean
   

On Windows*

Configure the build system

1. Change to the sample directory.

2. Configure the project to use the buffer-based implementation.

   mkdir build
   cd build
   cmake -G "NMake Makefiles" ..
   

   or

   Configure the project to use the Unified Shared Memory (USM) based implementation.

   mkdir build
   cd build
   cmake -G "NMake Makefiles" .. -DUSM=1
   

   Note: When building for FPGAs, the default FPGA family will be used (Intel® Agilex® 7). You can change the default target by using the command:

   cmake -G "NMake Makefiles" .. -DFPGA_DEVICE=<FPGA device family or FPGA part number>
   

   Alternatively, you can target an explicit FPGA board variant and BSP by using the following command:

   cmake -G "NMake Makefiles" .. -DFPGA_DEVICE=<board-support-package>:<board-variant>
   

   You will only be able to run an executable on the FPGA if you specified a BSP.

Build for CPU and GPU

1. Build the program.

   nmake cpu-gpu
   

2. Clean the program. (Optional)

   nmake clean
   

Troubleshooting

If an error occurs, you can get more details by running make with the VERBOSE=1 argument:

make VERBOSE=1

If you receive an error message, troubleshoot the problem using the Diagnostics Utility for Intel® oneAPI Toolkits. The diagnostic utility provides configuration and system checks to help find missing dependencies, permissions errors, and other issues. See the Diagnostics Utility for Intel® oneAPI Toolkits User Guide for more information on using the utility.

Run the Simple Add Program

On Linux

Run for CPU and GPU

1. Change to the output directory.

2. Run the program for Unified Shared Memory (USM) and buffers.

   ./gaussian-buffers
   ./gaussian-usm
   

On Windows

Run for CPU and GPU

1. Change to the output directory.

2. Run the program for Unified Shared Memory (USM) and buffers.

   Visual Studio Powershell window
   .\syclBufferArgs.exe
   

Example Output

oneApiPassBufferToFunction\build> .\syclBufferArgs.exe Starting main Running on device: Intel(R) UHD Graphics Error u8_data[0] = 0 does not equal init value 128.