mikkeli
bba48efd90
SocketCAN to yukart/can/raw and back, per frame or batched, with loss and latency from the kernel timestamp. No loss at a saturated 500 kbit/s bus; batched costs the broker ~1 % of a core. Report in docs/impl/reports. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01DDwfd6Ki8UfG4hK6W5YpJz
60 lines
2.3 KiB
Bash
Executable File
60 lines
2.3 KiB
Bash
Executable File
#!/usr/bin/env bash
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# Raw CAN over MQTT, measured on the car Orin against a vcan0 (project-yukart decision 4).
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# Runs on the Orin; sudo once, to create vcan0. Prints one JSON line per run: the
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# sink's and the bridge's reports, and mosquitto's CPU over the run.
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#
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# usage: bus-bench.sh BUS_BENCH_BINARY CAPTURE.log [secs]
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# env: BATCHES batch windows in ms, 0 = one message per frame ("0 10")
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# FLAGS extra options for both roles, e.g. --nagle
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# GAP_MS cangen gap for the full-bus run (0.15: ~4500 frames/s here, past what
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# 500 kbit/s can carry with 8-byte frames)
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set -euo pipefail
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BIN="$1"; CAPTURE="$2"; SECS="${3:-20}"
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BATCHES="${BATCHES:-0 10}"; FLAGS="${FLAGS:-}"
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if ! ip link show vcan0 >/dev/null 2>&1; then
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sudo modprobe vcan
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sudo ip link add vcan0 type vcan
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fi
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sudo ip link set vcan0 up txqueuelen 10000
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ticks() { awk '{print $14 + $15}' "/proc/$1/stat"; }
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HZ=$(getconf CLK_TCK)
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OUT=$(mktemp -d)
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# run NAME BATCH_MS GENERATOR...: the generator feeds vcan0 for a little over SECS seconds.
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run() {
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local name="$1" batch="$2"; shift 2
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# shellcheck disable=SC2086
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"$BIN" sink --secs "$SECS" $FLAGS > "$OUT/sink" 2>/dev/null &
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local sink=$!
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sleep 0.5
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# shellcheck disable=SC2086
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"$BIN" bridge --batch-ms "$batch" --secs $((SECS + 3)) $FLAGS > "$OUT/bridge" 2>/dev/null &
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local bridge=$!
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sleep 0.5
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local broker m0 m1 t0 t1
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broker=$(pgrep -x mosquitto); m0=$(ticks "$broker"); t0=$(date +%s.%N)
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timeout "$((SECS + 1))" "$@" >/dev/null 2>&1 || true
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m1=$(ticks "$broker"); t1=$(date +%s.%N)
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wait "$sink" "$bridge"
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python3 - "$name" "$batch" "$FLAGS" "$OUT" "$((m1 - m0))" "$HZ" "$t0" "$t1" <<'PY'
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import json, sys
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name, batch, flags, out, ticks, hz, t0, t1 = sys.argv[1:]
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r = {"run": name, "batch_ms": int(batch), "flags": flags,
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"sink": json.load(open(f"{out}/sink")), "bridge": json.load(open(f"{out}/bridge")),
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"mosquitto_cpu_pct": round(100 * int(ticks) / int(hz) / (float(t1) - float(t0)), 1)}
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for k in ("role",):
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r["sink"].pop(k); r["bridge"].pop(k)
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print(json.dumps(r))
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PY
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}
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LOOPS=$(( (SECS + 9) / 10 + 1 )) # the capture is 10 s; loop past the run's end
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for batch in $BATCHES; do
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run "car replay" "$batch" canplayer -l "$LOOPS" -I "$CAPTURE" vcan0=can_pcan
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run "full bus" "$batch" cangen vcan0 -g "${GAP_MS:-0.15}" -L 8
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run "flood" "$batch" cangen vcan0 -g 0 -L 8
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done
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