Windows Registry Editor Version 5.00

; =====================================================================
; NDIS Execution Context Profile – LowLatency (Moderate)
;
; Purpose:
;   Reduce packet queuing latency and jitter while avoiding extreme
;   dispatch churn or watchdog risk.
;
; Consumption model:
;   - Read once during miniport initialization
;   - Materialized into _EXECUTION_CONTEXT_RUNTIME_KNOBS
;   - Requires reboot or adapter disable/enable
;
; Registry root:
;   HKLM\SYSTEM\CurrentControlSet\Services\NDIS\Parameters\
;   Reserved\ExecutionContextProfiles\LowLatency
;
; Removal = rollback to defaults (profile not selected -> fallback)
; =====================================================================

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NDIS\Parameters\Reserved\ExecutionContextProfiles\LowLatency]

; ---------------------------------------------------------------------
; Global execution context controls
; ---------------------------------------------------------------------

; Flags
; Reserved execution context flags.
; Default: 0
; Guidance: Leave zero (client builds do not consume flags).
"Flags"=dword:00000000

; MaxTimeAtDispatch
; Forces exit from dispatch/DPC processing once packet limits are hit.
; Default: 0
; Effect: Caps worst-case DPC residency -> lower jitter.
"MaxTimeAtDispatch"=dword:00000001

; DpcWatchdogTimerThreshold
; Watchdog accounting threshold for long dispatch execution.
; Default: 0x50
; Guidance: Leave default unless debugging watchdog behavior.
"DpcWatchdogTimerThreshold"=dword:00000050

; WorkerThreadPriority
; Priority of NDIS passive-level worker threads.
; Default: 8
; Range: 1–15 (may be clamped)
; Guidance: Slight elevation improves completion latency without starvation.
"WorkerThreadPriority"=dword:00000009

; ---------------------------------------------------------------------
; SEND path – packet submission
; ---------------------------------------------------------------------

; MaxPacketsSendAtDispatch
; Max send packets processed per DPC iteration.
; Default: 64
; Lower = lower queuing latency, higher scheduling frequency.
"MaxPacketsSendAtDispatch"=dword:00000003

; MaxPacketsSendAtPassive
; Max send packets processed per passive worker iteration.
; Slightly higher than dispatch to smooth pacing.
"MaxPacketsSendAtPassive"=dword:00000006

; ---------------------------------------------------------------------
; SEND COMPLETE path – completion handling
; ---------------------------------------------------------------------

; MaxPacketsSendCompleteAtDispatch
; Max send completions per DPC iteration.
; Keep aligned with send dispatch limits.
"MaxPacketsSendCompleteAtDispatch"=dword:00000003

; MaxPacketsSendCompleteAtPassive
; Max send completions per passive iteration.
"MaxPacketsSendCompleteAtPassive"=dword:00000006

; ---------------------------------------------------------------------
; RECEIVE path – packet indication
; ---------------------------------------------------------------------

; MaxPacketsReceiveAtDispatch
; Max receive packets indicated per DPC iteration.
; Slightly higher than send to avoid RX starvation.
"MaxPacketsReceiveAtDispatch"=dword:00000004

; MaxPacketsReceiveAtPassive
; Max receive packets per passive worker iteration.
"MaxPacketsReceiveAtPassive"=dword:00000006

; ---------------------------------------------------------------------
; RECEIVE COMPLETE path – return processing
; ---------------------------------------------------------------------

; MaxPacketsReceiveCompleteAtDispatch
; Max receive completions per DPC iteration.
"MaxPacketsReceiveCompleteAtDispatch"=dword:00000004

; MaxPacketsReceiveCompleteAtPassive
; Max receive completions per passive iteration.
"MaxPacketsReceiveCompleteAtPassive"=dword:00000006

; =====================================================================
; Expected Runtime Characteristics:
;   - Reduced RX/TX queuing delay
;   - Improved hit registration consistency
;   - Stable frame-to-network pacing
;   - No extreme CPU overhead
;
; Verification ( W11 WinDbg):
;   dt _EXECUTION_CONTEXT_RUNTIME_KNOBS <Miniport>+0x1770
; =====================================================================

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NDIS\Parameters\Reserved\ExecutionContextProfiles]
"DefaultProfile"="LowLatency"