Add enhanced live vfsreadlat.py monitor BCC example with rich library

Author: r41k0u

BCC-Examples/vfsreadlat_rich.py

@@ -0,0 +1,178 @@
+from pythonbpf import bpf, map, struct, section, bpfglobal, BPF
+from pythonbpf.helper import ktime, pid
+from pythonbpf.maps import HashMap, PerfEventArray
+from ctypes import c_void_p, c_uint64
+
+from rich.console import Console
+from rich.live import Live
+from rich.table import Table
+from rich.panel import Panel
+from rich.layout import Layout
+import numpy as np
+import threading
+import time
+from collections import Counter
+
+# ==================== BPF Setup ====================
+
+
+@bpf
+@struct
+class latency_event:
+    pid: c_uint64
+    delta_us: c_uint64
+
+
+@bpf
+@map
+def start() -> HashMap:
+    return HashMap(key=c_uint64, value=c_uint64, max_entries=10240)
+
+
+@bpf
+@map
+def events() -> PerfEventArray:
+    return PerfEventArray(key_size=c_uint64, value_size=c_uint64)
+
+
+@bpf
+@section("kprobe/vfs_read")
+def do_entry(ctx: c_void_p) -> c_uint64:
+    p, ts = pid(), ktime()
+    start.update(p, ts)
+    return 0  # type: ignore [return-value]
+
+
+@bpf
+@section("kretprobe/vfs_read")
+def do_return(ctx: c_void_p) -> c_uint64:
+    p = pid()
+    tsp = start.lookup(p)
+
+    if tsp:
+        delta_ns = ktime() - tsp
+
+        if delta_ns > 1000:
+            evt = latency_event()
+            evt.pid, evt.delta_us = p, delta_ns // 1000
+            events.output(evt)
+
+        start.delete(p)
+
+    return 0  # type: ignore [return-value]
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+console = Console()
+console.print("[bold green]Loading BPF program...[/]")
+
+b = BPF()
+b.load()
+b.attach_all()
+
+# ==================== Data Collection ====================
+
+all_latencies = []
+histogram_buckets = Counter()  # type: ignore [var-annotated]
+
+
+def callback(cpu, event):
+    all_latencies.append(event.delta_us)
+    # Create log2 bucket
+    bucket = int(np.floor(np.log2(event.delta_us + 1)))
+    histogram_buckets[bucket] += 1
+
+
+b["events"].open_perf_buffer(callback, struct_name="latency_event")
+
+
+def poll_events():
+    while True:
+        b["events"].poll(100)
+
+
+poll_thread = threading.Thread(target=poll_events, daemon=True)
+poll_thread.start()
+
+# ==================== Live Display ====================
+
+
+def generate_display():
+    layout = Layout()
+    layout.split_column(
+        Layout(name="header", size=3),
+        Layout(name="stats", size=8),
+        Layout(name="histogram", size=20),
+    )
+
+    # Header
+    layout["header"].update(
+        Panel("[bold cyan]🔥 VFS Read Latency Monitor[/]", style="bold white on blue")
+    )
+
+    # Stats
+    if len(all_latencies) > 0:
+        lats = np.array(all_latencies)
+        stats_table = Table(show_header=False, box=None, padding=(0, 2))
+        stats_table.add_column(style="bold cyan")
+        stats_table.add_column(style="bold yellow")
+
+        stats_table.add_row("📊 Total Samples:", f"{len(lats):,}")
+        stats_table.add_row("⚡ Mean Latency:", f"{np.mean(lats):.2f} µs")
+        stats_table.add_row("📉 Min Latency:", f"{np.min(lats):.2f} µs")
+        stats_table.add_row("📈 Max Latency:", f"{np.max(lats):.2f} µs")
+        stats_table.add_row("🎯 P95 Latency:", f"{np.percentile(lats, 95):.2f} µs")
+        stats_table.add_row("🔥 P99 Latency:", f"{np.percentile(lats, 99):.2f} µs")
+
+        layout["stats"].update(
+            Panel(stats_table, title="Statistics", border_style="green")
+        )
+    else:
+        layout["stats"].update(
+            Panel("[yellow]Waiting for data...[/]", border_style="yellow")
+        )
+
+    # Histogram
+    if histogram_buckets:
+        hist_table = Table(title="Latency Distribution", box=None)
+        hist_table.add_column("Range", style="cyan", no_wrap=True)
+        hist_table.add_column("Count", justify="right", style="yellow")
+        hist_table.add_column("Distribution", style="green")
+
+        max_count = max(histogram_buckets.values())
+
+        for bucket in sorted(histogram_buckets.keys()):
+            count = histogram_buckets[bucket]
+            lower = 2**bucket
+            upper = 2 ** (bucket + 1)
+
+            # Create bar
+            bar_width = int((count / max_count) * 40)
+            bar = "█" * bar_width
+
+            hist_table.add_row(
+                f"{lower:5d}-{upper:5d} µs",
+                f"{count:6d}",
+                f"[green]{bar}[/] {count / len(all_latencies) * 100:.1f}%",
+            )
+
+        layout["histogram"].update(Panel(hist_table, border_style="green"))
+
+    return layout
+
+
+try:
+    with Live(generate_display(), refresh_per_second=2, console=console) as live:
+        while True:
+            time.sleep(0.5)
+            live.update(generate_display())
+except KeyboardInterrupt:
+    console.print("\n[bold red]Stopping...[/]")
+
+    if all_latencies:
+        console.print(f"\n[bold green]✅ Collected {len(all_latencies):,} samples[/]")