1 files changed, 60 insertions, 0 deletions
diff --git a/scripts/thread_cpu.py b/scripts/thread_cpu.py
new file mode 100755
index 0000000..f22ad51
--- /dev/null
+++ b/scripts/thread_cpu.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+"""Per-thread CPU of a process over an interval, grouped by thread name (Linux /proc).
+Shows where a smoke run's CPU goes: UI/render thread, audio thread, OpenAL mixer,
+compositor, GC... (smoke_run.sh step `threads:<s>`).
+
+Usage: scripts/thread_cpu.py PID SECONDS [--top N]
+"""
+import argparse
+import os
+import time
+from collections import defaultdict
+
+
+def sample(pid):
+    """{tid: (name, cpu_ticks)} for every live thread of pid."""
+    out = {}
+    base = f"/proc/{pid}/task"
+    for tid in os.listdir(base):
+        try:
+            with open(f"{base}/{tid}/stat") as f:
+                stat = f.read()
+        except OSError:
+            continue  # thread ended
+        name = stat[stat.index("(") + 1: stat.rindex(")")]
+        fields = stat[stat.rindex(")") + 2:].split()
+        out[tid] = (name, int(fields[11]) + int(fields[12]))  # utime + stime
+    return out
+
+
+def per_name(before, after, seconds, hz):
+    """[(name, percent of one core, thread count)] busiest first; threads that started
+    during the interval count from zero."""
+    total = defaultdict(float)
+    count = defaultdict(int)
+    for tid, (name, ticks) in after.items():
+        start = before.get(tid, (name, 0))[1]
+        total[name] += (ticks - start) * 100.0 / hz / seconds
+        count[name] += 1
+    return sorted(((n, total[n], count[n]) for n in total), key=lambda r: -r[1])
+
+
+def main():
+    ap = argparse.ArgumentParser()
+    ap.add_argument("pid", type=int)
+    ap.add_argument("seconds", type=float)
+    ap.add_argument("--top", type=int, default=10)
+    args = ap.parse_args()
+    hz = os.sysconf("SC_CLK_TCK")
+    a = sample(args.pid)
+    time.sleep(args.seconds)
+    b = sample(args.pid)
+    rows = per_name(a, b, args.seconds, hz)
+    print(f"threads: {sum(r[1] for r in rows):.1f}% total over {args.seconds:g}s")
+    for name, pct, n in rows[: args.top]:
+        if pct >= 0.05:
+            print(f"  {pct:5.1f}%  {name}" + (f" ×{n}" if n > 1 else ""))
+
+
+if __name__ == "__main__":
+    main()