Dynamic Traffic Shaping for PCIe Power-State Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Distributed data transmission between PCIe devices frequently interrupts the power-saving mode due to frequent link accesses, leading to inefficient power consumption.
Innovation Solution
Dynamic traffic shaping is implemented by adjusting a timer expiration time and packet count threshold based on throughput, holding packets until the expiration time or count threshold is reached, and transmitting them in batches over a PCIe bus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If distributed data transmission is performed between PCIe devices, then data communication is achieved, but the power-saving mode is frequently interrupted due to frequent link accesses
Solution Approach 1:
The system performs preliminary actions by adjusting the expiration time of the idle timer before data transmission occurs. When the processor determines that data transmission is about to occur, it proactively extends the timer expiration time, ensuring that the PCIe link remains in L0 state and preventing frequent transitions to power-saving modes, thus resolving the contradiction between maintaining productivity and reducing energy loss.
Solution Approach 2:
The system applies dynamics by dynamically adjusting the expiration time of the idle timer based on real-time detection of data transmission activities. The processor continuously monitors transmission patterns and adapts the timer settings accordingly, making the power management system flexible and responsive to actual workload conditions, thereby balancing data transmission efficiency with power conservation.
2Loss of energy
If the PCIe link transitions to power-saving mode, then power consumption is reduced, but data transmission is interrupted
Solution Approach 1:
The system implements feedback mechanisms where the processor continuously monitors data transmission status and uses this information to adjust the idle timer expiration time. When transmission activity is detected, the system feedback-adjusts the timer to prevent mode transitions, ensuring both power efficiency and transmission continuity are maintained through closed-loop control.
3Productivity
If the expiration time of the idle timer is extended, then the PCIe link remains in L0 state longer reducing power saving, but data transmission can occur without interruption
Solution Approach 1:
The system resolves this contradiction by making the expiration time dynamic rather than static. The processor adjusts the timer expiration time based on actual transmission needs - extending it when transmission is active to ensure smooth data flow, and allowing it to expire normally when idle to maintain power-saving effectiveness. This dynamic adaptation eliminates the need for a fixed compromise setting.
Data Source
AI summary
A method for performing dynamic traffic shaping is provided. The method includes adjusting an expiration time of a timer and a packet count threshold by a processor of a transmitting device according to throughput of transmission from an application of the transmitting device to a receiving device. The method includes holding application packets from the application by the processor until the expiration time expires or a packet count exceeds the packet count threshold, whichever occurs first. The method includes transmitting the application packets by the processor to the receiving device over an interconnectivity bus.