1. Getting Started¶

1.1.1. Reserving Hugepages¶

Hugepages must be enabled for running DPDK with high performance. Hugepage support is required to reserve large amount size of pages, 2MB or 1GB per page, to less TLB (Translation Lookaside Buffers) and to reduce cache miss. Less TLB means that it reduce the time for translating virtual address to physical.

Hugepage reservation might be different for 2MB or 1GB.

For 1GB page, hugepage setting must be activated while booting system. It must be defined in boot loader configuration, usually is /etc/default/grub. Add an entry to define pagesize and the number of pages. Here is an example. hugepagesz is for the size and hugepages is for the number of pages.

# /etc/default/grub
GRUB_CMDLINE_LINUX="default_hugepagesz=1G hugepagesz=1G hugepages=8"

$ cat /proc/cpuinfo | pdpe1gb

For 2MB page, you can activate hugepages while booting or at anytime after system is booted. Define hugepages setting in /etc/default/grub to activate it while booting, or overwrite the number of 2MB hugepages as following.

$ echo 1024 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages

In this case, 1024 pages of 2MB (totally 2048 MB) are reserved.

1.1.2. Mount hugepages¶

Make the memory available for using hugepages from DPDK.

$ mkdir /mnt/huge
$ mount -t hugetlbfs nodev /mnt/huge

It is also available while booting by adding a configuration of mount point in /etc/fstab, or after booted.

The mount point for 2MB or 1GB can be made permanent accross reboot. For 2MB, it is no need to declare the size of hugepages explicity.

# /etc/fstab
nodev /mnt/huge hugetlbfs defaults 0 0

For 1GB, the size of hugepage must be specified.

# /etc/fstab
nodev /mnt/huge_1GB hugetlbfs pagesize=1GB 0 0

1.1.3. Disable ASLR¶

SPP is a DPDK multi-process application and there are a number of limitations .

Address-Space Layout Randomization (ASLR) is a security feature for memory protection, but may cause a failure of memory mapping while starting multi-process application as discussed in dpdk-dev .

ASLR can be disabled by assigning kernel.randomize_va_space to 0, or be enabled by assigning it to 2.

# disable ASLR
$ sudo sysctl -w kernel.randomize_va_space=0

# enable ASLR
$ sudo sysctl -w kernel.randomize_va_space=2

You can check the value as following.

$ sysctl -n kernel.randomize_va_space

1.2.1. DPDK¶

Clone repository and compile DPDK in any directory.

$ cd /path/to/any
$ git clone http://dpdk.org/git/dpdk

To compile DPDK, required to install libnuma-devel library.

$ sudo apt install libnuma-dev

Python and pip are also required if not installed.

# Python2
$ sudo apt install python python-pip

# Python3
$ sudo apt install python3 python3-pip

SPP provides libpcap-based PMD for dumping packet to a file or retrieve it from the file. To use PCAP PMD, install libpcap-dev and enable it. text2pcap is also required for creating pcap file which is included in wireshark.

$ sudo apt install libpcap-dev
$ sudo apt install wireshark

PCAP is disabled by default in DPDK configuration. CONFIG_RTE_LIBRTE_PMD_PCAP and CONFIG_RTE_PORT_PCAP define the configuration and enabled it to y.

# dpdk/config/common_base
CONFIG_RTE_LIBRTE_PMD_PCAP=y
...
CONFIG_RTE_PORT_PCAP=y

Compile DPDK with target environment.

$ cd dpdk
$ export RTE_SDK=$(pwd)
$ export RTE_TARGET=x86_64-native-linuxapp-gcc  # depends on your env
$ make install T=$RTE_TARGET

1.2.2. SPP¶

Clone repository and compile SPP in any directory.

$ cd /path/to/any
$ git clone http://dpdk.org/git/apps/spp
$ cd spp
$ make  # Confirm that $RTE_SDK and $RTE_TARGET are set

1.2.3. Python 2 or 3 ?¶

You need to install Python for using usertools of DPDK or SPP controller. DPDK supports both of Python2 and 3. Howevrer, Python2 will not be maintained after 2020 and SPP is going to update only supporting Python3.

In SPP, it supports both of Python2 and 3 without spp-ctl currently, but is going to support only Python3 before the end of 2019.

1.3.1. UIO Drivers¶

You usually use the standard uio_pci_generic for many use cases or vfio-pci for more robust and secure cases. Both of drivers are included by default in modern Linux kernel.

# Activate uio_pci_generic
$ sudo modprobe uio_pci_generic

# or vfio-pci
$ sudo modprobe vfio-pci

You can also use kmod included in DPDK instead of uio_pci_generic or vfio-pci.

$ sudo modprobe uio
$ sudo insmod kmod/igb_uio.ko

1.3.2. Binding Network Ports¶

Once UIO driver is activated, bind network ports with the driver. DPDK provides usertools/dpdk-devbind.py for managing devices.

Find ports for binding to DPDK by running the tool with -s option.

$ $RTE_SDK/usertools/dpdk-devbind.py --status

Network devices using DPDK-compatible driver
============================================
<none>

Network devices using kernel driver
===================================
0000:29:00.0 '82571EB ... 10bc' if=enp41s0f0 drv=e1000e unused=
0000:29:00.1 '82571EB ... 10bc' if=enp41s0f1 drv=e1000e unused=
0000:2a:00.0 '82571EB ... 10bc' if=enp42s0f0 drv=e1000e unused=
0000:2a:00.1 '82571EB ... 10bc' if=enp42s0f1 drv=e1000e unused=

Other Network devices
=====================
<none>
....

You can find network ports are bound to kernel driver and not to DPDK. To bind a port to DPDK, run dpdk-devbind.py with specifying a driver and a device ID. Device ID is a PCI address of the device or more friendly style like eth0 found by ifconfig or ip command..

# Bind a port with 2a:00.0 (PCI address)
./usertools/dpdk-devbind.py --bind=uio_pci_generic 2a:00.0

# or eth0
./usertools/dpdk-devbind.py --bind=uio_pci_generic eth0

After binding two ports, you can find it is under the DPDK driver and cannot find it by using ifconfig or ip.

$ $RTE_SDK/usertools/dpdk-devbind.py -s

Network devices using DPDK-compatible driver
============================================
0000:2a:00.0 '82571EB ... 10bc' drv=uio_pci_generic unused=vfio-pci
0000:2a:00.1 '82571EB ... 10bc' drv=uio_pci_generic unused=vfio-pci

Network devices using kernel driver
===================================
0000:29:00.0 '...' if=enp41s0f0 drv=e1000e unused=vfio-pci,uio_pci_generic
0000:29:00.1 '...' if=enp41s0f1 drv=e1000e unused=vfio-pci,uio_pci_generic

Other Network devices
=====================
<none>
....