Brian Hanson
7a1e157c9c
py-spy showed per-cycle atomic param writes were the dominant cost. Each put() is mkstemp+fsync+flock+rename+fsync_dir — fine when rare, ruinous at 100Hz. At park with no state changes, these writes were running anyway and the flock contention was poisoning the whole system. carstate.py (update + update_canfd): CarSpeedLimit, CarIsMetric, CarCruiseDisplayActual were written every CAN update. Now cached and written only on change. controlsd.py: same fix for LatRequested and no_lat_lane_change. Also throttle the sentry crash-file stat() from 100Hz to 1Hz. Also: suppress locationdTemporaryError/paramsdTemporaryError/posenetInvalid on lat engage (same 2s window as commIssue), and tie suppression to the LatRequested edge instead of CC.latActive (fires immediately, not after the 250ms ramp-up delay). Also: reset Ratekeeper when it falls >1s behind — the ~6s fingerprinting stall at startup was poisoning the lag metric for the entire session. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Car port structure
interface.py
Generic interface to send and receive messages from CAN (controlsd uses this to communicate with car)
fingerprints.py
Fingerprints for matching to a specific car
carcontroller.py
Builds CAN messages to send to car
carstate.py
Reads CAN from car and builds openpilot CarState message
values.py
Limits for actuation, general constants for cars, and supported car documentation
radar_interface.py
Interface for parsing radar points from the car