Add shenandoah-jdk28: generational vs SATB Shenandoah, G1 and ZGC on a Spring Boot service (JEP 535 status probe included)

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01HmvoHH3ZnCEaPNXRpDxDZe

shenandoah-jdk28/scripts/summarize.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python3
+"""Median across repetitions, one row per configuration. usage: summarize.py output/02-runs.txt"""
+import re
+import statistics
+import sys
+from collections import OrderedDict
+
+rows = OrderedDict()
+for line in open(sys.argv[1]):
+    if "FAILED" in line or not line.strip():
+        continue
+    kv = dict(re.findall(r"(\w+)=([^\s]+)", line))
+    rows.setdefault(kv["label"], []).append({k: float(v) for k, v in kv.items() if k not in ("label",)})
+
+cols = [
+    ("p50 ms", "p50_ms", "{:.2f}"),
+    ("p99 ms", "p99_ms", "{:.1f}"),
+    ("p99.9 ms", "p999_ms", "{:.1f}"),
+    ("max ms", "max_ms", "{:.1f}"),
+    ("peak req/s", "peak_rps", "{:.0f}"),
+    ("pauses", "pauses", "{:.0f}"),
+    ("pause p99 ms", "pause_p99_ms", "{:.3f}"),
+    ("pause max ms", "pause_max_ms", "{:.3f}"),
+    ("pause total ms", "pause_total_ms", "{:.0f}"),
+    ("RSS MB", "rss_peak_mb", "{:.0f}"),
+]
+reps = max(len(v) for v in rows.values())
+print(f"median of {reps} runs per configuration (latency from a fixed-rate open loop; throughput from a closed loop)")
+print()
+print(f"{'configuration':<26}" + "".join(f"{c[0]:>15}" for c in cols))
+for label, runs in rows.items():
+    cells = [c[2].format(statistics.median(r[c[1]] for r in runs)) for c in cols]
+    print(f"{label:<26}" + "".join(f"{x:>15}" for x in cells))