nx_blkprofile.nx

nx_blkprofile.nx -- THE BURST PROFILER for the D-state admission witness. Rung DG1, /compare/degradation. WHY THIS EXISTS, IN THE CONF'S OWN WORDS. knowledge/build_admit.conf carries blocked_samples and blocked_gap_ms -- THE SMOOTHED WITNESS -- and leaves them DELIBERATELY UNARMED behind a written work order: "sample procs_blocked at a fixed interval for a few minutes and find the shortest span over which the median stops tracking the bursts ... Then write the sample count, the gap, and the run that produced them on this line." That derivation had never been run, so a capability the conf itself measured at roughly 42 percent of build refusals sat inert. THIS ORGAN IS THAT DERIVATION. IT REFUSES TO RECOMMEND A SPAN IT DID NOT MEASURE. Every row below is produced by replaying a REAL recorded series through the REAL median, so a recommendation here is a measurement, never a taste. IT COMPOSES THE SHIPPING RULERS AND RE-IMPLEMENTS NEITHER. ioa_measure reads /proc/stat exactly as nx_build_admit does, and ioa_median IS the median nx_build_admit applies once armed. The verdicts in the span table are therefore the verdicts THE ARMED GATE WOULD HAVE PRODUCED on this series -- not an approximation, and not a second ruler that can drift from the first. THE LATENCY COLUMN IS NOT DECORATION. The conf refuses arming until that cost is measured, because the span is paid by EVERY caller of the admission check -- the clock dispatcher's pre-dispatch call included. A span that fixes admission and stalls the dispatcher has moved the defect, not removed it. TWO TIMESCALES, TWO VERBS. `live` samples fine enough to resolve a 2-12 s burst. `jrnl` re-reads the procchurn journal the estate ALREADY writes, for the long-run base rate at zero added load -- a second reader of an old log, never a second collector. NO CLOCK IS READ. sys_time_ms is ABSENT-PROVEN in this runtime (buildroot/runtime, corpus_complete=1), so the window is reported as NOMINAL and derived from the sample count and interval. The added-latency column needs no clock either: a sampler that sleeps a span pays that span BY CONSTRUCTION.