Noise ripped out after the bench verdict (tightly-wrapped unshielded cables move victim SNR only 0.2-0.3 dB, recorded in measurement.md dead ends): noise.go deleted with the noiser, phase clock and panel lane; configureNoise/checkPrivFlag gone so the X710 pair is untouched; console noise column, NOISE links rows and lane colors removed; driverPair rehomed to system.go, carrierUp to phy.go; history anchors to run start (frame-rate sampling and draw-clock roll kept — they fix display latency for every lane); goals/hardware/state/nics docs updated; verified on hardware (20.00G, zero errors, ECD 41m, SNR +7.6)

2026-08-17 21:37:18 -07:00
parent be2bf56fa7
commit 66ff49f9d2
13 changed files with 60 additions and 382 deletions
@@ -53,6 +53,7 @@ Measured in the E810 era; the binding constraint was total CPU across ~28 gorout
 - **CPU pinning** — the Go scheduler beats manual placement; E-cores are poor at TX.
 - **Batch sizes above 64** — no gain, worse loss.
 - **Chasing the TX `sendmmsg` busy-spin on ENOBUFS** — it only exists when the TX ring is full, which means the wire is the ceiling; recovering that CPU buys no packets. POLLOUT is inert under PACKET_QDISC_BYPASS (skb freed on ENOBUFS, socket always reports writable).
+- **Alien-crosstalk injection from an intertwined noise cable** — bench-measured: two unshielded cables tightly wrapped moved the victim's per-pair SNR margin only 0.2–0.3 dB, far too little to stress even a marginal cable; 10GBASE-T's alien-noise budget absorbs it. The noise pair, its link-cycling, and the panel lane are removed from the tool.

 ## rxnfc flow-rule programming — three traps (found on ice; 1 and 2 are kernel-ABI-generic)