2021.1 Vitis™ Application Acceleration Development Flow Tutorials

See 2020.2 Vitis Application Acceleration Development Flow Tutorials

Optimizing Accelerated FPGA Applications: Bloom Filter Example

Introduction

The methodology for accelerating applications on an FPGA is comprised of multiple phases:

  • Architecting the application: Make key decisions about the architecture of the application and decide some important factors, such as what software functions should be mapped to FPGA kernels, how much parallelism is needed, and how it should be delivered.

  • Developing the accelerator to meet your desired performance goals: Implement the kernel by modifying the source code and applying pragmas to create a kernel architecture that can achieve the desired performance goals.

  • Optimize the host code: Review the application’s access patterns, data movements, CPU and FPGA idle time, and update the host code to meet your performance goals.

You begin this tutorial with a baseline application, and you profile the application to examine the potential for hardware acceleration. The tutorial application involves searching through an incoming stream of documents to find the documents that closely match a user’s interest based on a search profile.

In general, a Bloom filter application has use cases in data analytics, such as browsing through unstructured email and text file data to identify the documents that are closely associated with a specific user and send notifications accordingly.

Before You Begin

TIP: This tutorial takes approximately two hours to complete.

The labs in this tutorial use:

  • BASH Linux shell commands.

  • 2021.1 Vitis core development kit release and the xilinx_u200_gen3x16_xdma_1_202110_1 platform. If necessary, it can be easily ported to other versions and platforms.

This tutorial guides you to run the designed accelerator on the FPGA; therefore, the expectation is that you have an Xilinx® Alveo™ U200 Data Center accelerator card set up to run this tutorial. Because it can take several (six or seven) hours to generate the multiple xclbin files needed to run the accelerator, pregenerated xclbin files are provided for the U200 card. To use these pregenerated files, when building the hardware kernel or running the accelerator on hardware, you need to add the SOLUTION=1 argument.

IMPORTANT:

  • Before running any of the examples, make sure you have installed the Vitis core development kit as described in Installation in the Application Acceleration Development flow of the Vitis Unified Software Platform Documentation (UG1416).

  • If you run applications on Alveo cards, ensure the card and software drivers have been correctly installed by following the instructions on the Alveo Portfolio page.

Accessing the Tutorial Reference Files

  1. To access the tutorial content, enter the following in a terminal: git clone http://github.com/Xilinx/Vitis-Tutorials.

  2. Navigate to the Hardware_Acceleration/Design_Tutorials/02-bloom directory.

    • cpu_src contains all the original source code before modification.

    • images contains the figures in this tutorial.

    • Makefile in the makefile directory explains the commands used in this lab. Use the PLATFORM variable if targeting different platforms.

    • reference_file contains the modified kernel and host-related files for achieving higher performance.

  3. Copy and extract large files in as follows:

    wget https://www.xilinx.com/bin/public/openDownload?filename=xclbin_save.tar.gz -O xclbin_save.tar.gz
tar -xvzf  xclbin_save.tar.gz

    TIP: The xclbin_save contains the saved xclbin files that can be used directly for running on hardware by setting SOLUTION=1 for the make run commands.