4 ms·
What are the disadvantages of kernel bypass?
by anonymousDan 7y ago
What are the disadvantages of kernel bypass?
- parliament32 7y agoYou don't get kernel features anymore, and have to re-implement the ones you need yourself.
- ra1n85 7y agoCorrect - things you take for granted like ARP and TCP/IP are completely up to you to take care of. Further, the Kernel has little visibility into most kernel bypass stacks, so /proc or iproute are often blind to what's happening. DPDK does have "kernel interfaces", so you can direct packets to the kernel.
- StillBored 7y agoYou also tend to end up dedicating cores. That is a side effect of spinning in a loop checking for the next packet/queue processing rather than waiting for an interrupt. There is also the additional overhead of VFIO/IOMMU's which can easily eat double digit perf vs doing the processing in a trusted kernel context. So with a normal machine the cores/etc are balanced between processes, with DPDK/etc thats hard as some of the cores will be 100% consumed in those spinloops even if your experiencing 5% line rate.