Same-session PTY flood increases input echo latency #73

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opened 2026-10-07 09:43:20 +00:00 by kayg · 1 comment

kayg commented

2026-10-07 09:43:20 +00:00

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On infraternal-dev (x86_64, 8 cores), the real-agent PTY latency gate measured 100 samples at the default 300 ms RTT ±30 ms. The native phase load was 4.57 6.87 10.08. Baseline PTY echo p99 was 329.47 ms; with yes flooding the same session it was 449.58 ms, a 120.11 ms increase against the 16.67 ms one-frame isolation budget. Echo-confirmed p99 under the same-session flood was 312.34 ms (334 ms budget). Reproduce with scripts/verify latency or python3 scripts/verify-latency.py --binary <release-binary> --samples 100. The test and full evidence are in issue #55.

On infraternal-dev (x86_64, 8 cores), the real-agent PTY latency gate measured 100 samples at the default 300 ms RTT ±30 ms. The native phase load was 4.57 6.87 10.08. Baseline PTY echo p99 was 329.47 ms; with `yes` flooding the same session it was 449.58 ms, a 120.11 ms increase against the 16.67 ms one-frame isolation budget. Echo-confirmed p99 under the same-session flood was 312.34 ms (334 ms budget). Reproduce with `scripts/verify latency` or `python3 scripts/verify-latency.py --binary <release-binary> --samples 100`. The test and full evidence are in issue #55.

kayg referenced this issue

2026-10-07 09:43:36 +00:00

Tests: high latency by default + input-to-photon gate (D130) #55

kayg referenced this issue

2026-10-07 10:32:58 +00:00

Tests: high latency by default + input-to-photon gate (D130) #55

kayg commented

2026-10-07 10:32:58 +00:00

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Latest real-agent PTY flood gate on infraternal-dev (x86_64, 8 cores; native load 14.01/9.92/7.08), n=100, 300 ms RTT ±30 ms:
METRIC name=keystroke_pty_echo_baseline source=real-agent-pty n=100 p50_ms=300.58 p99_ms=329.06 budget_ms=334.00 result=PASS
METRIC name=keystroke_pty_echo_flood_other_session source=real-agent-pty n=100 p50_ms=318.03 p99_ms=326.25 budget_ms=334.00 result=PASS
METRIC name=flood_isolation_other_session source=real-agent-pty n=100 baseline_p99_ms=329.06 flood_p99_ms=326.25 growth_ms=-2.81 budget_ms=16.67 result=PASS
METRIC name=keystroke_echo_confirmed_flood_same_session source=real-agent-pty n=100 p50_ms=319.19 p99_ms=333.73 budget_ms=334.00 result=PASS
METRIC name=keystroke_pty_echo_flood_same_session source=real-agent-pty n=100 p50_ms=339.07 p99_ms=382.24 budget_ms=334.00 result=FAIL
METRIC name=flood_isolation_same_session source=real-agent-pty n=100 baseline_p99_ms=329.06 flood_p99_ms=382.24 growth_ms=53.18 budget_ms=16.67 result=FAIL
Same-session PTY output echo rises 53.18 ms at p99 against a 16.67 ms allowance. Full profile log was $HOME/.cache/codex-scratch/latency-gate/latency-final.log.

Latest real-agent PTY flood gate on infraternal-dev (x86_64, 8 cores; native load 14.01/9.92/7.08), n=100, 300 ms RTT ±30 ms: `METRIC name=keystroke_pty_echo_baseline source=real-agent-pty n=100 p50_ms=300.58 p99_ms=329.06 budget_ms=334.00 result=PASS` `METRIC name=keystroke_pty_echo_flood_other_session source=real-agent-pty n=100 p50_ms=318.03 p99_ms=326.25 budget_ms=334.00 result=PASS` `METRIC name=flood_isolation_other_session source=real-agent-pty n=100 baseline_p99_ms=329.06 flood_p99_ms=326.25 growth_ms=-2.81 budget_ms=16.67 result=PASS` `METRIC name=keystroke_echo_confirmed_flood_same_session source=real-agent-pty n=100 p50_ms=319.19 p99_ms=333.73 budget_ms=334.00 result=PASS` `METRIC name=keystroke_pty_echo_flood_same_session source=real-agent-pty n=100 p50_ms=339.07 p99_ms=382.24 budget_ms=334.00 result=FAIL` `METRIC name=flood_isolation_same_session source=real-agent-pty n=100 baseline_p99_ms=329.06 flood_p99_ms=382.24 growth_ms=53.18 budget_ms=16.67 result=FAIL` Same-session PTY output echo rises 53.18 ms at p99 against a 16.67 ms allowance. Full profile log was `$HOME/.cache/codex-scratch/latency-gate/latency-final.log`.

kayg referenced this issue

2026-10-07 10:55:40 +00:00

Tests: high latency by default + input-to-photon gate (D130) #55

kayg referenced this issue from a commit

2026-10-10 09:20:35 +00:00

Merge latency-gate: 300 ms RTT test profile and input-to-photon gate (#55, D130)

kayg referenced this issue

2026-10-13 12:57:15 +00:00

Lessons from tmux and zellij issue trackers #206

kayg referenced this issue

2026-10-28 17:52:29 +00:00

Tests: high latency by default + input-to-photon gate (D130) #55