XPerf
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pp-json-hot — measured, still hint

Status

hint. Wall-clock JSONL: pp-json-hot.jsonl. Not corpus-triaged. The 2026-10-22 corpus verdict does not cover this slug.

Measurement

20000 loads of one fixed JSON object. After parses once and rereads the field. A payload that changes every iteration cannot use this after shape.

rolecasemedian_msopsratio
afterloads_once0.699000200001
beforeloads_each_iter20.0005842000028.613

CPython 3.15.1, 2026-10-23. Warm 3, median of 9. After parses once and rereads the field.

The microbench shows a cost for this one shape. Default stays hint until the shape is corpus-triaged. This ratio is not a general speedup.

Unblock

Do not set the default to error from this file alone. A changing input, a cold path, or another ABI can erase the difference. Corpus triage is still required before any default change.