~bigbes/tarantool-protobuf: fe857ac0

bench: alloc decomposition probe

Adds bench/alloc_probe.lua, a surgical probe that strips the
encode path apart and measures KB-delta per primitive operation.
Lets us attribute the ~136 B/op encode floor (captured in the
perf-analysis-2026-05-18 memo) to a specific source: result
table, intermediate varint strings, output string, etc.

Runs with GC stopped so allocations accumulate; divides by N to
get bytes-per-op. Uses unique input bytes per iteration where
appropriate to eliminate string-interning noise.

Complements bench/profile.lua (where time goes) with where
*memory* goes — the two together informed which bd perf items
were worth landing (the bytes-saved had to translate to a real
allocation rate change, not just a hot-line attribution).

Eugene Blikh <bigbes@gmail.com> — 2026-05-18 19:51:34 UTC

Commit fe857ac03631666de689cd0973ce68459505f745 — view raw patch

Parent(s): a0f0ce2d

1 changed file(s)

FileStatus+−
bench/alloc_probe.lua A +167