Graviton2 is optimized for data path functions like networking and storage. Users of DPDK and SPDK can download and compile natively on Graviton2 following the normal installation guidelines from the respective repositories linked above.
NOTE: Though DPDK precompiled packages are available from Ubuntu but we recommend building them from source.
SPDK relies often on ISA-L which is already optimized for Arm64 and the CPU cores in Graviton2.
DPDK official guidelines requires using meson and ninja to build from source code.
A native compilation of DPDK on top of Graviton2 will generate optimized code that take advantage of the CRC and Crypto instructions in Graviton2 cpu cores.
NOTE: Some of the installations steps call "python" which may not be valid command in modern linux distribution, you may need to install python-is-python3 to resolve this.
If a developer is using the makefile-based build (vs the newer meson), the following patch will enable a Graviton2 optimized build.
In some older releases (prior to DPDK 20.11), some default parameters are not optimal and developers should check the values:
- RTE_MAX_LCORE, should at least be 64
- RTE_CACHE_LINE_SIZE=64
Some application, written with the x86 architecture in mind, set the active dpdk threads or lcores to 1/2 number of vCPU to run single thread per physical core on x86 and disabling SMT. However, in Graviton, every vCPU is a full CPU, and a developer can use more threads or lcores than same size x86-based instance. For example, a c5.16xl has 64vCPU or 32 physical cores, but some DPDK application would only run on 32 to guarantee one thread per physical core. In c6g.16xl, developer can use 64 physical cores.
- testpmd: The flowgen function of testpmd does not work correctly when compiled with GCC 9 and above. It generates IP packets with wrong checksum which are dropped when transmitted between AWS instances (including Graviton2). This is a known issue and there is a patch that fixes it.