Stop your eBPF tracepoints from bloating your kernel ring buffer

Technical Briefing | 8/3/2026

I watched a junior dev deploy an eBPF probe to catch a weird networking hiccup last week, and within ten minutes, the machine was flapping. They had attached a kprobe to a hot syscall without any filtering, turning the kernel into a firehose of event data. It is easy to think more visibility is always better, but if you do not gate what your tracer sees, you are just performing a self-inflicted denial-of-service attack.

Why your probes are louder than you think

When you attach a program to a tracepoint that fires thousands of times per second, the overhead adds up. Even a simple bpf_printk can cause significant jitter because it dumps everything into the trace_pipe, competing for the same resources your application needs to survive. You need to keep the data processing inside the kernel and only send the summaries up to userspace.

bpftool prog attach pinned /sys/fs/bpf/my_filter tracepoint net:net_dev_xmit

• Use maps to aggregate data locally before sending it to userspace
• Restrict your probes to specific PIDs to avoid monitoring every process on the box
• Always define a tail call or a condition to drop events that do not match your error criteria

Filtering at the edge of the kernel

The goal is to move the filtering logic as close to the event trigger as possible. If you are tracking latency, store the start timestamp in a hash map and calculate the duration immediately. Only trigger a log or an alert when the result exceeds your defined threshold. By the time the data hits your log aggregator, it should be an actionable metric, not a raw log stream of every single packet traversal.

Next time you are setting up a probe, force yourself to write a counter that tracks how many events you are dropping. If that number stays at zero, you are probably logging too much and missing the signal in the noise. Take a step back, refine your filter logic, and keep your kernel footprint small enough that you can leave the probe running without a second thought.