enricobuehler
99f60b5b08
ci / rust (push) Has been cancelled
From the latency investigation: the freeze-fix pacing (paced_submit) was the single biggest software-controllable latency term — it unconditionally spread EVERY multi-chunk frame over ~90% of the frame interval, adding up to ~7.5 ms @120 / ~15 ms @60 to a frame's last packet even when the frame was small or the link idle. Recover that on the common case while keeping the freeze fix: - Microburst-cap pacing: a frame whose sealed size is <= a cap (default 128 KB, PUNKTFUNK_PACE_BURST_KB) goes out in ONE immediate burst — no pacing latency. Only the OVERFLOW of a bigger frame (IDR / sustained high bitrate, the bursts that actually overran the tx buffer and froze) is spread. 128 KB is well under the ~150 Mbps@60 frame size where drops began, so the default is safe; raise it after confirming send_dropped stays 0 on a given link. Still never slower than unpaced (budget collapses to 0 with no slack). seal-once/in-order nonce preserved — chunks are split, never reordered or re-sealed. - Per-frame instrumentation (PUNKTFUNK_PERF, zero-cost off): encode_us + pace_us (the pacing tail) p50/p99/max histograms + immediate-vs-paced frame counts in the periodic perf line, so the pacing tail is finally visible and the cap is tunable against real numbers. Host builds + clippy + fmt green. NOT yet deployed to the running hosts (still on the safe full-pacing A+B build) — needs the user's LAN soak to validate the cap doesn't reintroduce send_dropped before raising it. Deferred bigger bets (need real-NIC/GPU/Mac validation): encode|send thread split on the native path, CUDA stream+event (one redundant sync), NVENC slice wrapper, stage-2 Apple presenter, glass-to-glass probe — see docs/roadmap.md. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>