Streaming DMA Accelerator Functional Unit User Guide: Intel® Programmable Acceleration Card with Intel® Arria® 10 GX FPGA

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ID 683840
Date 3/06/2020
Public
Document Table of Contents
Document Table of Contents x
1. About this Document 2. Streaming DMA AFU Description 3. Memory Map and Address Spaces 4. Software Programming Model 5. Running the AFU Example 6. Compiling the Accelerator Function (AF) 7. Simulating the AFU Example 8. Streaming DMA AFU User Guide Archives 9. Document Revision History for Streaming DMA Accelerator Functional Unit User Guide A. Enabling Hugepages
1. About this Document x
1.1. Intended Audience 1.2. Conventions 1.3. Acronyms 1.4. Acceleration Glossary
2. Streaming DMA AFU Description x
2.1. Hardware Subsystems 2.2. Streaming DMA Test System 2.3. Memory-to-Stream DMA BBB 2.4. Stream-to-Memory DMA BBB
3. Memory Map and Address Spaces x
3.1. Streaming DMA AFU Memory Map 3.2. Memory-to-Stream DMA BBB Memory Map 3.3. Stream-to-Memory DMA BBB Memory Map 3.4. Device Feature Header Linked-list
5. Running the AFU Example x
5.1. Optimization for Improved DMA Performance
1. About this Document
2. Streaming DMA AFU Description
3. Memory Map and Address Spaces
4. Software Programming Model
5. Running the AFU Example
6. Compiling the Accelerator Function (AF)
7. Simulating the AFU Example
8. Streaming DMA AFU User Guide Archives
9. Document Revision History for Streaming DMA Accelerator Functional Unit User Guide
A. Enabling Hugepages

A. Enabling Hugepages

This section covers information about how to enable 1 GB hugepages temporarily and persistently. Intel® recommends you to begin by temporarily enabling huge pages and later if you want to avoid revisiting the steps to enable hugepages persistently.

Temporarily Enabling 1 GB Hugepages

If you have already boot your system into the operating system, you can enable two 1 GB hugepages by running the following command: 
sudo sh -c "echo 2 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages"
You can also enable two 1 GB hugepages and twenty 2 MB hugepages at boot time by passing the following boot time arguments to GRUB: 
default_hugepagesz=2MB hugepagesz=1G hugepages=2 hugepagesz=2M hugepages=20

By enabling 2 MB hugepages as the default hugepage size, when software allocates buffers between 4 KB and 2 MB the memory allocation system will default to 2 MB hugepages instead of 1 GB hugepages. Some of the other acceleration stack examples require up to twenty 2 MB hugepages so setting both page sizes as shown above will allow those designs to continue operating correctly using the same settings.

Persistently Enabling 1 GB Hugepages

This section explains how to enable two 1 GB hugepages and twenty 2 MB hug pages persistently so that the setting remains persistent across reboots and power cycles.
  • In Ubuntu: Perform the following steps to enable two 1 GB hugepages and twenty 2 MB hugepages on a Ubuntu system:
    1. Edit /etc/default/grub and add the following text to the end of the file:
      GRUB_CMDLINE_LINUX_DEFAULT="${GRUB_CMDLINE_LINUX_DEFAULT} default_hugepagesz=2MB hugepagesz=1G hugepages=2 hugepagesz=2M hugepages=20"
    2. Save the GRUB file.
    3. Update GRUB by committing the updated settings:
      sudo update-grub
    4. Reboot the system.
  • In RHEL: Perform the following steps to enable two 1 GB hugepages and twenty 2 MB hugepages on a RHEL system:
    1. Edit /etc/default/grub and add the following text to the end of the file:
      GRUB_CMDLINE_LINUX="${GRUB_CMDLINE_LINUX} default_hugepagesz=2MB hugepagesz=1G hugepages=2 hugepagesz=2M hugepages=20"
    2. Save the GRUB file.
    3. Update GRUB by committing the updated settings:
      sudo grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
    4. Reboot the system.

Persistently Disabling 1 GB Hugepages

To revert your system back to its default boot settings, follow the instructions from section Persistently Enabling 1 GB Hugepages and remove the text that you added in step 1, and then follow steps 2 to 4. If you need to periodically enable and disable hugepages, instead of removing test from step 1 simply comment out the line by post-pending "#" to comment the line out.
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