interrupt monitor

2026-07-09 19:42:56 +00:00
parent 047de27b32
commit a37a82b346
1 changed files with 100 additions and 0 deletions
--- a/monitor-interrupts-by-type.py
+++ b/monitor-interrupts-by-type.py
@@ -0,0 +1,100 @@
+#!/usr/bin/env python3
+"""Monitor per-second interrupt rates for one CPU (or TOTAL), sorted by type."""
+
+import sys
+import time
+
+
+def parse_interrupts():
+    """Parse /proc/interrupts.
+
+    Returns (cpu_names, rows) where rows maps label -> (counts, description).
+    counts is a list of per-CPU integers; description is the trailing text
+    (e.g. "IO-APIC 2-edge timer" or "Local timer interrupts").
+    """
+    rows = {}
+    with open("/proc/interrupts") as f:
+        cpu_names = f.readline().split()
+        num_cpus = len(cpu_names)
+        for line in f:
+            parts = line.split()
+            if not parts:
+                continue
+            label = parts[0].rstrip(":")
+            counts = []
+            i = 1
+            while i < len(parts) and len(counts) < num_cpus:
+                try:
+                    counts.append(int(parts[i]))
+                except ValueError:
+                    break
+                i += 1
+            if not counts:
+                continue
+            description = " ".join(parts[i:])
+            rows[label] = (counts, description)
+    return cpu_names, rows
+
+
+def resolve_cpu(arg, cpu_names):
+    """Resolve a CPU argument to an index, or None for TOTAL."""
+    if arg.upper() == "TOTAL":
+        return None
+    name = arg if arg.upper().startswith("CPU") else f"CPU{arg}"
+    name = name.upper()
+    for idx, cpu in enumerate(cpu_names):
+        if cpu.upper() == name:
+            return idx
+    print(f"Unknown CPU '{arg}'. Available: {', '.join(cpu_names)}, TOTAL", file=sys.stderr)
+    sys.exit(1)
+
+
+def value_for(counts, cpu_idx):
+    """Return the count for the selected CPU, or the sum for TOTAL."""
+    if cpu_idx is None:
+        return sum(counts)
+    if cpu_idx < len(counts):
+        return counts[cpu_idx]
+    return 0
+
+
+def main():
+    if len(sys.argv) < 2:
+        print(f"Usage: {sys.argv[0]} <cpu-index|CPU0|TOTAL> [interval-secs]", file=sys.stderr)
+        sys.exit(1)
+
+    cpu_names, prev_rows = parse_interrupts()
+    cpu_idx = resolve_cpu(sys.argv[1], cpu_names)
+    interval = float(sys.argv[2]) if len(sys.argv) > 2 else 1.0
+
+    target = "TOTAL (all CPUs)" if cpu_idx is None else cpu_names[cpu_idx]
+    print(f"Monitoring interrupts on {target} every {interval:g}s, sorted by rate (Ctrl-C to stop)\n")
+
+    prev = {label: value_for(counts, cpu_idx) for label, (counts, _) in prev_rows.items()}
+
+    try:
+        while True:
+            time.sleep(interval)
+            _, curr_rows = parse_interrupts()
+            deltas = []
+            for label, (counts, description) in curr_rows.items():
+                curr = value_for(counts, cpu_idx)
+                delta = curr - prev.get(label, curr)
+                if delta > 0:
+                    deltas.append((delta, label, description))
+                prev[label] = curr
+
+            deltas.sort(reverse=True)
+            total = sum(d for d, _, _ in deltas)
+            print(f"===== {total} interrupts/{interval:g}s on {target} =====")
+            print(f"{'RATE':>10}  {'IRQ':<8}  {'TYPE'}")
+            print("-" * 60)
+            for delta, label, description in deltas:
+                print(f"{delta:>10}  {label:<8}  {description}")
+            print()
+    except KeyboardInterrupt:
+        print()
+
+
+if __name__ == "__main__":
+    main()