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* Measure the CPU a record costs a link, against quinn (096)eunhhu2026-09-291-0/+122
M5 of design 011. At first a link spent eight times quinn's CPU on a small record: scans of the backlog, a system call and allocations a record, 19 bytes of framing. After the seven changes before this one, the transport alone (transport.c; a backlog drained, every record checked) spends per record 0.30 us for 61 bytes (quinn 0.27: 1.06 to 1.12 times over three campaigns, at the design's 10 % line), 2.91 us for 1,013 bytes (quinn 3.88) and 45.2 us for 16,013 bytes (quinn 60.9): 25 % less for the larger ones, and 30 % more records a second. What is left for small records is per packet: the stream's names and the RECORDS head. quinn's numbers carry no confirmation of storing and no exactly once. Between two pure-serve nodes the links spend more per record, woken at the receiving app's pace. Filling the sender showed the outbox is written whole at every save, as the numbers heard were (094): the next thing to change. run.py gains --transport and --drain; the quinn service reads a drain a chunk at a time and its client writes 64 KiB at a time.