xerj-org · Sep 22, 2026 · Sep 22, 2026 · Sep 22, 2026
diff --git a/benchmarks/idle-budget/README.md b/benchmarks/idle-budget/README.md
@@ -178,6 +178,52 @@ Overrides (`GATE_CPU_PERCENT`, `GATE_WAKEUPS_PER_S`,
 defaults are the CI contract. If a gate fails, the finding is the point — do
 not move the line to make a run pass.
 
+### Calibration update, 2026-09-22 — #1024 tranche 1 (lazy request-cache seen-set)
+
+`6526e8ea` (`perf(#1024): request-cache seen-set allocates on first tracked
+search`) removed the eager `RequestCacheSeen::with_capacity(65_536)` at both
+`Index` construction sites: the seen-set now starts empty and grows on first
+`record()`, so an index that has never served a `request_cache=true` search
+holds nothing. Same host, same fixture, `ci-test` binaries, allocator pins
+on; before-binary rebuilt from `ed510a61` (the commit's parent, single-file
+diff). Result files: `result-p1024-n150-4cpu.json`,
+`result-p1024-n450-4cpu.json` (before, 4-vCPU), `result-p1024-after-n150-4cpu.json`,
+`result-p1024-after-n450-4cpu.json` (after, 4-vCPU), `result-p1024-before-32cpu-n450.json`
+/ `result-p1024-after-32cpu.json` / `result-p1024-after-32cpu-rerun.json`
+(32-vCPU N=450 pair — the before arm was added because every earlier 32-vCPU
+reading was N=300).
+
+| 4-vCPU (`taskset -c 0-3`) | before | after | Δ |
+|---|---|---|---|
+| per-index idle RSS, N=150 | 204.9 kB | 63.2 kB | −69 % |
+| per-index idle RSS, N=450 | 203.7 kB | 63.3 kB | −69 % |
+| N-slope, VmRSS (450−150)/300 | 206.5 kB/idx | 63.7 kB/idx | −69 % |
+| N-slope, RssAnon (450−150)/300 | 205.7 kB/idx | 68.8 kB/idx | −67 % |
+| idle CPU, N=450 | 0.225 % | 0.192 % | −15 %rel |
+| wakeups/s, N=450 | 25.2 | 21.4 | − |
+| boot-to-green, N=450 | 6 ms | 6 ms | — |
+| WAL replay after clean flush | 0 | 0 | — |
+
+| 32 vCPU (unpinned), N=450 | before | after (2 runs) |
+|---|---|---|
+| per-index idle RSS | 199.0 kB | 66.3 / 62.6 kB |
+| idle CPU | 0.767 % (loadavg 19) | 0.650 / 0.633 % (loadavg 3–4) |
+| wakeups/s | 22.6 | 25.9 / 22.2 |
+| boot-to-green | 385 ms (loaded window) | 113 / 7 ms |
+
+The subtraction and the N-slope now agree (~64 kB/idx): the curve is flat at
+a genuinely O(N)-constant ~0.06 MB/index, and issue #874's 0.2 MB/index
+product line is met on both host shapes with >3× margin. The remaining
+~64 kB/idx is the next tranche's target (per-index DashMap shard arrays,
+WAL/memtable shard structs, parsed settings/mapping copies).
+
+Pre-existing, unchanged by this commit: the unpinned 32-vCPU arm at N=450
+reads >0.5 % idle CPU on the **before** binary too (0.767 %) — the gate line
+was calibrated on 4-vCPU and quiet-N=300 windows, and both binaries trip it
+on that arm on this shared box. The controlled 4-vCPU pair above is the
+comparison that matters; wakeups (the timer-churn proxy) are flat on every
+arm. The issue stays open for the follow-up tranches.
+
 ## Reproduce
 
 ```sh

diff --git a/benchmarks/idle-budget/results/result-p1024-after-32cpu-rerun.json b/benchmarks/idle-budget/results/result-p1024-after-32cpu-rerun.json
@@ -0,0 +1,108 @@
+{
+ "label": "p1024-after-32cpu-rerun",
+ "date_utc": "2026-09-22T04:21:14+00:00",
+ "binary": {
+  "version": "xerj v1.0.0-rc.77",
+  "path": "/root/xerj-1024/engine/target/ci-test/xerj"
+ },
+ "corpus": {
+  "shape": "15x30",
+  "indices": 450,
+  "docs_per_index": 3
+ },
+ "port": 9610,
+ "window_s": 120.0,
+ "settle_target_s": 120.0,
+ "boot_ms": {
+  "empty_node": 7,
+  "baseline_arm": 6,
+  "n_indices": 7
+ },
+ "wal_replay_lines_after_clean_flush": 0,
+ "doc_probe_hits": 3,
+ "baseline": {
+  "pid": 3779830,
+  "window_s": 120.0,
+  "clk_tck": 100,
+  "cpu_ticks": 11,
+  "cpu_percent_of_one_core": 0.0917,
+  "wakeups_per_s": 23.7,
+  "voluntary_per_s": 23.7,
+  "nonvoluntary_per_s": 0.1,
+  "rss_kb": 77892,
+  "hwm_kb": 78860,
+  "rss_anon_kb": 47404,
+  "rss_file_kb": 30488,
+  "anon_hugepages_kb": 0,
+  "threads": 340,
+  "fds": 15,
+  "per_thread_cpu": [
+   {
+    "comm": "xerj-mem-sample",
+    "cpu_ticks": 4,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.033
+   },
+   {
+    "comm": "xerj-rt",
+    "cpu_ticks": 3,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.025
+   },
+   {
+    "comm": "xerj-memtable-s",
+    "cpu_ticks": 1,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.008
+   }
+  ],
+  "loadavg_start": [
+   "2.45",
+   "10.52",
+   "12.76"
+  ]
+ },
+ "measurement": {
+  "pid": 3781903,
+  "window_s": 120.0,
+  "clk_tck": 100,
+  "cpu_ticks": 76,
+  "cpu_percent_of_one_core": 0.6333,
+  "wakeups_per_s": 22.2,
+  "voluntary_per_s": 21.9,
+  "nonvoluntary_per_s": 0.4,
+  "rss_kb": 106084,
+  "hwm_kb": 106084,
+  "rss_anon_kb": 73636,
+  "rss_file_kb": 32448,
+  "anon_hugepages_kb": 0,
+  "threads": 336,
+  "fds": 15,
+  "per_thread_cpu": [
+   {
+    "comm": "xerj-rt",
+    "cpu_ticks": 64,
+    "threads": 3,
+    "cpu_percent_of_one_core": 0.533
+   },
+   {
+    "comm": "xerj-memtable-s",
+    "cpu_ticks": 8,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.067
+   },
+   {
+    "comm": "xerj-mem-sample",
+    "cpu_ticks": 4,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.033
+   }
+  ],
+  "loadavg_start": [
+   "3.24",
+   "7.58",
+   "11.29"
+  ]
+ },
+ "per_index_rss_kb": 62.6
+}
diff --git a/benchmarks/idle-budget/results/result-p1024-after-32cpu.json b/benchmarks/idle-budget/results/result-p1024-after-32cpu.json
@@ -0,0 +1,108 @@
+{
+ "label": "p1024-after-32cpu",
+ "date_utc": "2026-09-22T04:06:02+00:00",
+ "binary": {
+  "version": "xerj v1.0.0-rc.77",
+  "path": "/root/xerj-1024/engine/target/ci-test/xerj"
+ },
+ "corpus": {
+  "shape": "15x30",
+  "indices": 450,
+  "docs_per_index": 3
+ },
+ "port": 9610,
+ "window_s": 120.0,
+ "settle_target_s": 120.0,
+ "boot_ms": {
+  "empty_node": 5,
+  "baseline_arm": 7,
+  "n_indices": 113
+ },
+ "wal_replay_lines_after_clean_flush": 0,
+ "doc_probe_hits": 3,
+ "baseline": {
+  "pid": 3772779,
+  "window_s": 120.0,
+  "clk_tck": 100,
+  "cpu_ticks": 11,
+  "cpu_percent_of_one_core": 0.0917,
+  "wakeups_per_s": 23.7,
+  "voluntary_per_s": 23.5,
+  "nonvoluntary_per_s": 0.2,
+  "rss_kb": 76540,
+  "hwm_kb": 76644,
+  "rss_anon_kb": 47304,
+  "rss_file_kb": 29236,
+  "anon_hugepages_kb": 0,
+  "threads": 340,
+  "fds": 15,
+  "per_thread_cpu": [
+   {
+    "comm": "xerj-mem-sample",
+    "cpu_ticks": 4,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.033
+   },
+   {
+    "comm": "xerj-rt",
+    "cpu_ticks": 3,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.025
+   },
+   {
+    "comm": "xerj-memtable-s",
+    "cpu_ticks": 2,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.017
+   }
+  ],
+  "loadavg_start": [
+   "3.34",
+   "3.76",
+   "7.98"
+  ]
+ },
+ "measurement": {
+  "pid": 3774882,
+  "window_s": 120.0,
+  "clk_tck": 100,
+  "cpu_ticks": 78,
+  "cpu_percent_of_one_core": 0.6499,
+  "wakeups_per_s": 25.9,
+  "voluntary_per_s": 25.5,
+  "nonvoluntary_per_s": 0.4,
+  "rss_kb": 106360,
+  "hwm_kb": 106360,
+  "rss_anon_kb": 74008,
+  "rss_file_kb": 32352,
+  "anon_hugepages_kb": 0,
+  "threads": 336,
+  "fds": 15,
+  "per_thread_cpu": [
+   {
+    "comm": "xerj-rt",
+    "cpu_ticks": 62,
+    "threads": 3,
+    "cpu_percent_of_one_core": 0.517
+   },
+   {
+    "comm": "xerj-memtable-s",
+    "cpu_ticks": 10,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.083
+   },
+   {
+    "comm": "xerj-mem-sample",
+    "cpu_ticks": 3,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.025
+   }
+  ],
+  "loadavg_start": [
+   "3.57",
+   "3.86",
+   "7.35"
+  ]
+ },
+ "per_index_rss_kb": 66.3
+}
diff --git a/benchmarks/idle-budget/results/result-p1024-after-n150-4cpu.json b/benchmarks/idle-budget/results/result-p1024-after-n150-4cpu.json
@@ -0,0 +1,108 @@
+{
+ "label": "p1024-after-n150-4cpu",
+ "date_utc": "2026-09-22T03:59:12+00:00",
+ "binary": {
+  "version": "xerj v1.0.0-rc.77",
+  "path": "/root/xerj-1024/engine/target/ci-test/xerj"
+ },
+ "corpus": {
+  "shape": "5x30",
+  "indices": 150,
+  "docs_per_index": 3
+ },
+ "port": 9610,
+ "window_s": 120.0,
+ "settle_target_s": 120.0,
+ "boot_ms": {
+  "empty_node": 5,
+  "baseline_arm": 5,
+  "n_indices": 5
+ },
+ "wal_replay_lines_after_clean_flush": 0,
+ "doc_probe_hits": 3,
+ "baseline": {
+  "pid": 3771285,
+  "window_s": 120.0,
+  "clk_tck": 100,
+  "cpu_ticks": 7,
+  "cpu_percent_of_one_core": 0.0583,
+  "wakeups_per_s": 24.7,
+  "voluntary_per_s": 24.6,
+  "nonvoluntary_per_s": 0.1,
+  "rss_kb": 47140,
+  "hwm_kb": 47144,
+  "rss_anon_kb": 16696,
+  "rss_file_kb": 30444,
+  "anon_hugepages_kb": 0,
+  "threads": 82,
+  "fds": 15,
+  "per_thread_cpu": [
+   {
+    "comm": "xerj-mem-sample",
+    "cpu_ticks": 3,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.025
+   },
+   {
+    "comm": "xerj-rt",
+    "cpu_ticks": 1,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.008
+   },
+   {
+    "comm": "xerj-memtable-s",
+    "cpu_ticks": 1,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.008
+   }
+  ],
+  "loadavg_start": [
+   "4.04",
+   "5.27",
+   "10.45"
+  ]
+ },
+ "measurement": {
+  "pid": 3771786,
+  "window_s": 120.0,
+  "clk_tck": 100,
+  "cpu_ticks": 17,
+  "cpu_percent_of_one_core": 0.1417,
+  "wakeups_per_s": 24.7,
+  "voluntary_per_s": 24.6,
+  "nonvoluntary_per_s": 0.1,
+  "rss_kb": 56620,
+  "hwm_kb": 56620,
+  "rss_anon_kb": 24196,
+  "rss_file_kb": 32424,
+  "anon_hugepages_kb": 0,
+  "threads": 82,
+  "fds": 15,
+  "per_thread_cpu": [
+   {
+    "comm": "xerj-mem-sample",
+    "cpu_ticks": 5,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.042
+   },
+   {
+    "comm": "xerj-memtable-s",
+    "cpu_ticks": 4,
+    "threads": 1,
+    "cpu_percent_of_one_core": 0.033
+   },
+   {
+    "comm": "xerj-rt",
+    "cpu_ticks": 3,
+    "threads": 2,
+    "cpu_percent_of_one_core": 0.025
+   }
+  ],
+  "loadavg_start": [
+   "3.59",
+   "4.70",
+   "9.48"
+  ]
+ },
+ "per_index_rss_kb": 63.2
+}