Development record
2026-10-29 — Declined part of iss-2610241414124940's remedy: once a run holds a slot, the gate does not switch to judging capacity by the slot count alone and keeps its load limit. Grounds, the timeout evidence of the two records: on 2026-10-24, with several preflights' test stages admitted together at a load near 20 on 10 cores, six packages hit their 20-minute per-binary timeouts in one run, so admitting more than one at a time made all of them fail (iss-2610241414124940); and the gate opened a whole run at load 17.8 on 10 cores, under its limit, after which three packages (claim, implement/loop, surface/cli) hit the 20-minute timeout because the load stayed near the threshold for the whole run (iss-2610241911052191). Admitting by slots past the load would admit more runs into exactly that load. The starvation that part answered came from queued runs' ungated stages feeding the load they waited on, which whole-run admission removes (itd-2610262127138979): a queued run now does no work. The idle-slot part of the same remedy is carried by iss-2610262155232329. The same record's 2026-10-25 evidence points the other way from slot-only admission too: a run admitted alone at load 8.5 on 10 cores still timed out three packages while the machine's on-access scanner used one to two cores, a cost the load average does not show, so the load is if anything an optimistic signal there; admission on measured headroom is the draft itd-2610262141001890.
2026-10-29 — Declined part of iss-2610241414124940's remedy: once a run holds a slot, the gate does not switch to judging capacity by the slot count alone and keeps its load limit. Grounds, the timeout evidence of the two records: on 2026-10-24, with several preflights' test stages admitted together at a load near 20 on 10 cores, six packages hit their 20-minute per-binary timeouts in one run, so admitting more than one at a time made all of them fail (iss-2610241414124940); and the gate opened a whole run at load 17.8 on 10 cores, under its limit, after which three packages (claim, implement/loop, surface/cli) hit the 20-minute timeout because the load stayed near the threshold for the whole run (iss-2610241911052191). Admitting by slots past the load would admit more runs into exactly that load. The starvation that part answered came from queued runs' ungated stages feeding the load they waited on, which whole-run admission removes (itd-2610262127138979): a queued run now does no work. The idle-slot part of the same remedy is carried by iss-2610262155232329. The same record's 2026-10-25 evidence points the other way from slot-only admission too: a run admitted alone at load 8.5 on 10 cores still timed out three packages while the machine's on-access scanner used one to two cores, a cost the load average does not show, so the load is if anything an optimistic signal there; admission on measured headroom is the draft itd-2610262141001890.
Frontmatter
| id | dcn-2610290741094304 |
|---|---|
| type | decision |
| date | 2026-10-29 |
.abcd/work/decisions/dcn-2610290741094304-declined-part-of-iss-2610241414124940-s.md
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mentions5
- iss-2610241414124940The preflight load gate can starve every waiter on a busy machine and holds its only slot for a hung command. It opens only while the one-minute load is below twice the online cores (20 on 10 cores), but the preflight stages it does not gate (lint, record gates, evals, build, vet) run before it, so seven sessions' preflights on 2026-10-24 kept the load near 25 and the gate never opened: one drain lane's preflight ended 'load gate still shut after 2h0m0s: load 20.9 is not below 20 (2 x 10 online cores); 3 make preflights are running'. Later the same day, at 14:04 UTC, the load was 8 on 10 cores and about nine preflights were still queued, their logs unchanged for 45 minutes, because the one open slot (~/.abcd.noindex/load-wait.json, form command, opened 13:19 UTC, held to 14:19) belonged to a package test run that had used about 11% CPU for 45 minutes; load.preflights was 2, yet only one slot was open, possibly because waiters started before the setting was written read one slot when they began. Nothing reclaims a slot whose holder is idle, and nothing lets the gate open when the load it waits on comes from the ungated stages of its own queued runs. Adjacent records on an unmerged branch cover the ungated stages running unbounded and the unmeasured wait, which this issue does not restate.
- iss-2610241911052191The load gate opened a whole make preflight at load 17.8 on ten cores, under the 20 threshold, yet three packages (internal/core/claim, internal/core/implement/loop, internal/surface/cli) then hit the twenty-minute test timeout, because the other sessions' ungated stages kept the load near the threshold for the whole run
- iss-2610262155232329A load-gate slot held by a run that has stopped using the machine is never released: a holder that hangs or idles keeps its slot until its own timeout, and every other waiter waits behind it (part of the remedy of iss-2610241414124940, split out of itd-2610262127138979 at its planning on 2026-10-26, because whole-run admission does not decide it). Admitting a run on the headroom it will need rather than the load at one instant (part of iss-2610241911052191) moves with it to the adaptive count, itd-2610262141001890.
- itd-2610262127138979A preflight waits for its turn as one whole run
- itd-2610262141001890abcd adjusts how many preflights run at once from what it recorded