Count instructions where timing cannot tell 3% apart (110)

016's second stage passed its criterion: six interleaved pairs against
ee21aec gave TPC-C (RAM, W=1) -0.6% at the median and the bank's
queries 0.0% to +2.2%, no run interfered. The ranks query was slower
all six times, and chasing it showed that on this Pi timing cannot
separate 1-3%: two servers asked in turns disagree with themselves
(ee21aec to e02bfc9 +1.6%, e02bfc9 to 481642f -1.2%, ee21aec to 481642f
+2.8%), and a query whose instructions grew 0.6% ran 3.5% faster.

Instructions do not move so: pcount.c counts the server's user-mode
instructions with perf_event_open (no perf here), and psample.c samples
where they go. ranks had grown 0.4% in instructions (the rest was where
code and data landed), per_branch 3.6% and tables 20 instructions a row,
which 07047c3 halved. The six pairs of 07047c3 were interfered (another
session's build, load 4-12) and are kept apart, unused.

1 files changed, 3 insertions, 0 deletions

diff --git a/research/experiments/025-i64-cost/fc65d66/2026-09-30-tpcc-before-4-linux-aarch64.jsonl b/research/experiments/025-i64-cost/fc65d66/2026-09-30-tpcc-before-4-linux-aarch64.jsonl
new file mode 100644
index 0000000..7d2d521
--- /dev/null
+++ b/research/experiments/025-i64-cost/fc65d66/2026-09-30-tpcc-before-4-linux-aarch64.jsonl
@@ -0,0 +1,3 @@
+{"step": "load", "directory": "/dev/shm", "warehouses": 1, "rows": 568758, "generate_s": 0.56, "pure_load_s": 0.71, "sqlite_load_s": 1.58, "sqlite_page_size": 4096, "pure_resident_mib": 38.2, "sqlite_file_mib": 13.8}
+{"step": "run", "system": "pure", "warehouses": 1, "terminals": 64, "transactions_per_second": 44200, "new_orders_per_minute": 1182404, "undone_new_orders": 3789, "errors": 0, "new_order": {"done": 397924, "failed": 0, "p50_us": 1472, "p99_us": 3328}, "payment": {"done": 379945, "failed": 0, "p50_us": 1408, "p99_us": 3328}, "order_status": {"done": 35457, "failed": 0, "p50_us": 248, "p99_us": 1088}, "delivery": {"done": 35437, "failed": 0, "p50_us": 1408, "p99_us": 3200}, "stock_level": {"done": 35245, "failed": 0, "p50_us": 272, "p99_us": 1216}, "server_threads": "3", "cpu_us_per_transaction": 43.0, "core_shares": {"pure-owner": 0.9, "pure-checkpoint": 0.01}, "resident_mib": 461.9, "written_bytes_per_transaction": 0.0, "device_bytes_per_transaction": null, "consistency_failures": []}
+{"step": "end", "pure_resident_mib": 461.9, "pure_state_mib": 235.1, "pure_store_mib": 238.7, "sqlite_files_mib": 13.8, "grouped_sqlite_files_mib": 0.0, "pure_counts": {"bursts": 26618, "burst_events": 809602, "checkpoints": 40}}