eBPF and Kernel Tracing: Deep Linux Kernel Observation with BCC and bpftrace

eBPF (extended Berkeley Packet Filter) is a revolutionary technology that allows safe code execution directly inside the Linux Kernel without modifying the kernel or loading modules. Combined with tools like BCC (BPF Compiler Collection) and bpftrace, you can observe deep kernel activities in real-time, detect I/O, CPU, and network bottlenecks that traditional monitoring tools like top, htop, or Prometheus cannot see. This article provides a detailed guide on implementing eBPF on VPS to optimize system performance in 2026.

1. What is eBPF and Why is it Powerful?

eBPF allows you to attach probes (kprobe, uprobe, tracepoint) at any point in the kernel to collect data with minimal performance impact. It is an essential tool for DevOps and SRE teams when deep performance debugging is required.

• Advantages: Safe, high-speed, runs in kernel space.
• Real-world Applications: Analyzing disk latency, CPU scheduler, network packet drops, memory allocation.
• Compared to old tools: No server reboot required, low overhead.

// Interface simulating eBPF tracing result
interface KernelEvent {
  timestamp: number;
  pid: number;
  processName: string;
  eventType: "io_latency" | "cpu_sched" | "net_drop" | "syscall";
  latencyNs?: number;
  details: string;
}

class EbpfTracer {
  private events: KernelEvent[] = [];

  recordEvent(event: KernelEvent) {
    this.events.push(event);
    if (event.latencyNs && event.latencyNs > 1000000) { // > 1ms
      console.warn(`[eBPF ALERT] High latency detected: ${event.processName} (${event.latencyNs / 1000000} ms)`);
    }
  }

  getTopLatency() {
    return this.events
      .filter(e => e.latencyNs)
      .sort((a, b) => (b.latencyNs || 0) - (a.latencyNs || 0))
      .slice(0, 5);
  }
}
 

2. VPS Requirements for Running eBPF

eBPF requires kernel support (Linux 4.4+, recommended 5.10+).

Factor	Recommendation
Kernel Version	5.15+ (Ubuntu 22.04/24.04)
CPU	4+ cores
RAM	8GB+
Storage	NVMe SSD

3. Installing BCC and bpftrace

BCC provides advanced Python/C++ tools, while bpftrace offers simple awk-like syntax.

// Bash script to install eBPF tools (simulated in TypeScript)
const installEbpfScript = `
sudo apt update
sudo apt install -y bpfcc-tools linux-headers-\$(uname -r) bpftrace
# Check if eBPF is working
sudo bpftrace -l | head -n 10
`;

console.log("BCC tools and bpftrace installed successfully");
 

4. Observing I/O Latency with eBPF

Identify which processes are causing disk bottlenecks.

// bpftrace I/O analysis script illustration (TypeScript logic)
function traceDiskLatency() {
  console.log("[eBPF] Starting block I/O latency trace...");

  const ioEvents = [
    { pid: 1234, comm: "nginx", latency: 2450000 },
    { pid: 5678, comm: "mysql", latency: 12400000 },
    { pid: 9012, comm: "postgres", latency: 890000 }
  ];

  ioEvents.forEach(event => {
    const latencyMs = (event.latency / 1000000).toFixed(2);
    console.log(`[I/O] ${event.comm} (PID ${event.pid}) - Latency: ${latencyMs} ms`);
    
    if (parseFloat(latencyMs) > 5) {
      console.error(`[BOTTLENECK] High I/O latency detected on ${event.comm}`);
    }
  });
}

traceDiskLatency();
 

5. Tracing CPU Scheduler and Syscalls

Use bpftrace to see which processes are being preempted frequently or have slow syscalls.

// CPU Scheduler Tracing Example
interface SchedEvent {
  pid: number;
  comm: string;
  delayNs: number;
  reason: string;
}

function analyzeScheduler(events: SchedEvent[]) {
  console.log("[eBPF] Analyzing CPU Scheduler events");

  events.forEach(e => {
    if (e.delayNs > 5000000) { // > 5ms
      console.warn(`[SCHED] ${e.comm} delayed ${ (e.delayNs / 1000000).toFixed(2) }ms - Reason: ${e.reason}`);
    }
  });
}

// Example
analyzeScheduler([
  { pid: 4321, comm: "node", delayNs: 12400000, reason: "waiting for I/O" },
  { pid: 8765, comm: "python", delayNs: 890000, reason: "preempt" }
]);
 

6. Best Practices When Using eBPF

• Only trace when necessary to avoid unnecessary overhead.
• Combine eBPF with Prometheus + Grafana for visualization.
• Use bpftrace for quick debugging, BCC for production tools.
• Always check permissions (CAP_SYS_ADMIN or root).
• Keep track of kernel version as eBPF evolves rapidly.

7. Conclusion: eBPF Tracing Deployment Checklist

Before applying in production, verify the following:

1. Does your VPS kernel fully support eBPF (CONFIG_BPF=y)?
2. Have you installed BCC tools and bpftrace?
3. Do you have ready-made trace scripts for I/O, CPU, and Network?
4. Have you integrated alerts for high latency detection?
5. Do you have a plan for storing and analyzing trace data?
6. Do you fully understand the overhead before long-term use?

eBPF has completely changed how we debug and optimize Linux systems. With BCC and bpftrace, you can see deep into the kernel, detect and fix bottlenecks that were previously nearly impossible to find. This is an advanced skill every System Engineer should master in 2026.

Hope this guide helps you fully harness the power of eBPF on your VPS!