hardConceptDesignSeniorStaff
What cost does kernel-bypass networking actually remove, and what do you give up to get it?
5 min readUpdated 2026-08-15
Answer
Short answer
Kernel bypass moves packet handling into user space so a market-data read no longer pays a syscall boundary, a kernel-to-user copy, interrupt and softirq handling, or a scheduler wakeup.
Was this answer helpful?
Likely follow-ups
- If you kept the kernel stack but pinned threads and enabled busy-polling on the socket, how much of the bypass win would you expect to keep?
- How do you reproduce a packet-loss incident on a bypass path when tcpdump cannot see the traffic?
- Where in a market-data-to-order pipeline is the first place bypass stops helping, and what dominates from there?
- How would you run two independent strategy processes on one bypass-capable interface without one starving the other?
Related questions
- How would you design an order book, and what makes it hard?hardAlso on market-data and low-latency7 min
- Why does the standard Linux network stack fail at MMO scale, and how do you bypass it using DPDK?hardAlso on kernel-bypass and networking2 min
- Why do low-latency systems preallocate arenas instead of calling the general-purpose allocator on the hot path?hardAlso on jitter7 min
- Your application cannot reach a service that should be up. Walk me through diagnosing it from the shell.mediumAlso on networking6 min