Hello everyone Check out this short article about why XDP was chosen over DPDK. The reasoning for this decision is also explained. https://gcore.com/blog/how-we-use-regular-expressions-in-xdp-for-packet-filtering/ BR, Andrey ср, 14 дек. 2022 г. в 16:20, Federico Parola <federico.parola@xxxxxxxxx>: > > On 12/14/22 10:00, Magnus Karlsson wrote: > > On Wed, Dec 14, 2022 at 9:16 AM Federico Parola > > <federico.parola@xxxxxxxxx> wrote: > >> > >> Hello everyone, > >> in a context in which all traffic is sent to user space, and the main > >> concern is performance (so AF_XDP busy polling is the best candidate), > >> is there a reason to choose AF_XDP instead of DPDK for packet I/O, given > >> that the latter is still much faster? > > > > The choice is not AF_XDP vs DPDK, since DPDK can run on top of AF_XDP. > > The choice is do you want to use user-space drivers or kernel space > > drivers. There are many pros and cons with both approaches. The two > > main advantages of user-space drivers in DPDK are that they are faster > > than their kernel counterparts and you get access to many NIC features > > that are not available right now from user-space if you are using a > > kernel driver. Kernel drivers, on the other hand, enables you to > > deploy your application on any Linux system (from a certain version) > > and does not force you into the strict execution model of DPDK (which > > is what most people use with user-space drivers). Everything in Linux > > is still usable and it is easy to have a system that mixes data-plane > > processing with other types of workloads. If the only thing you care > > about is max performance of a pure packet processing workload on a > > system you have complete control over, the choice is easy: go with a > > user-space driver and DPDK. If this is not your ultimate goal, then > > XDP and AF_XDP might be something to consider. > Thanks for your answer Magnus. > > - Concerning deploying an application on any Linux system, what could be > the limitations of DPDK userspace drivers that AF_XDP doesn't have? The > use of hugepages? > > - Concerning a system that mixes data-plane processing with other types > of workloads, do you refer only to the capability of XDP to steer > traffic either towards userspace with AF_XDP or let it proceed to the > kernel? Or are there other features of DPDK userspace drivers that would > impact this kind of system? Maybe the use of busy polling is too > aggressive to share the CPU with other workloads? > > > > > There are likely some good write-ups on the Internet about this. > > > > /Magnus > > > >> Best regards, > >> Federico Parola ср, 14 дек. 2022 г. в 16:20, Federico Parola <federico.parola@xxxxxxxxx>: > > On 12/14/22 10:00, Magnus Karlsson wrote: > > On Wed, Dec 14, 2022 at 9:16 AM Federico Parola > > <federico.parola@xxxxxxxxx> wrote: > >> > >> Hello everyone, > >> in a context in which all traffic is sent to user space, and the main > >> concern is performance (so AF_XDP busy polling is the best candidate), > >> is there a reason to choose AF_XDP instead of DPDK for packet I/O, given > >> that the latter is still much faster? > > > > The choice is not AF_XDP vs DPDK, since DPDK can run on top of AF_XDP. > > The choice is do you want to use user-space drivers or kernel space > > drivers. There are many pros and cons with both approaches. The two > > main advantages of user-space drivers in DPDK are that they are faster > > than their kernel counterparts and you get access to many NIC features > > that are not available right now from user-space if you are using a > > kernel driver. Kernel drivers, on the other hand, enables you to > > deploy your application on any Linux system (from a certain version) > > and does not force you into the strict execution model of DPDK (which > > is what most people use with user-space drivers). Everything in Linux > > is still usable and it is easy to have a system that mixes data-plane > > processing with other types of workloads. If the only thing you care > > about is max performance of a pure packet processing workload on a > > system you have complete control over, the choice is easy: go with a > > user-space driver and DPDK. If this is not your ultimate goal, then > > XDP and AF_XDP might be something to consider. > Thanks for your answer Magnus. > > - Concerning deploying an application on any Linux system, what could be > the limitations of DPDK userspace drivers that AF_XDP doesn't have? The > use of hugepages? > > - Concerning a system that mixes data-plane processing with other types > of workloads, do you refer only to the capability of XDP to steer > traffic either towards userspace with AF_XDP or let it proceed to the > kernel? Or are there other features of DPDK userspace drivers that would > impact this kind of system? Maybe the use of busy polling is too > aggressive to share the CPU with other workloads? > > > > > There are likely some good write-ups on the Internet about this. > > > > /Magnus > > > >> Best regards, > >> Federico Parola -- Andrey Slastenov Network Expert CCIE #19983 Email:a.slastenov@xxxxxxxxx
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