Dynamic Processor Frequency Selection for Contended Resource Waiting

Solution Overview

Problem

Current processor frequency reduction techniques at runtime are inefficient, particularly when waiting for contended resources like locks, as they often result in wasted resources and suboptimal performance across varying processor capabilities, leading to inefficient battery life and increased heat output.

Innovation Solution

A dynamic processor frequency selection system that measures cycles spent waiting for contended resources using a looping prediction function, retains this data with branch history information, and dynamically reduces processor frequency during predicted waiting periods, allowing for optimized resource usage and efficient task completion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If processor frequency is reduced at runtime to conserve resources, then battery life is extended and power consumption is reduced, but performance is degraded and task completion time increases

Engineering Contradiction:

Improvepower consumptionVSAvoidtask completion speed

Core Design Contradiction:

Use of energy by moving objectVSProductivity

Solution Approach 1:

The system dynamically adjusts processor frequency based on runtime conditions, specifically detecting when the processor is waiting for contended resources and reducing frequency only during those waiting periods rather than maintaining a static frequency setting. This allows the processor to operate at high frequency when productive and low frequency when idle-waiting, resolving the contradiction between power consumption and task completion speed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the processor frequency parameter based on detected waiting conditions for contended resources. By monitoring resource contention and adjusting the frequency parameter dynamically, the system optimizes power consumption during waiting periods while maintaining high performance during active computation, thus resolving the contradiction between energy efficiency and productivity.

Inventive Principle:

Principle #35Parameter changes

2Temperature

If processor frequency is reduced during waiting periods, then heat output is reduced, but overall system performance is degraded

Engineering Contradiction:

Improveheat outputVSAvoidinstruction execution speed

Core Design Contradiction:

TemperatureVSProductivity

Solution Approach 1:

The system dynamically adjusts processor frequency based on runtime conditions, specifically detecting when the processor is waiting for contended resources and reducing frequency only during those waiting periods rather than maintaining a static frequency setting. This allows the processor to operate at high frequency when productive and low frequency when idle-waiting, resolving the contradiction between power consumption and task completion speed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the processor frequency parameter based on detected waiting conditions for contended resources. By monitoring resource contention and adjusting the frequency parameter dynamically, the system optimizes power consumption during waiting periods while maintaining high performance during active computation, thus resolving the contradiction between energy efficiency and productivity.

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If processor frequency is dynamically adjusted based on resource waiting, then resource efficiency is improved, but system complexity increases

Engineering Contradiction:

Improveresource efficiencyVSAvoidfrequency control mechanism

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The processor system monitors its own resource waiting conditions and autonomously adjusts its frequency without requiring external control. The branch predictor and frequency selection module work together to detect waiting periods and automatically adjust frequency, making the system self-regulating and reducing the need for complex external control mechanisms.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system uses branch prediction information as feedback about resource waiting conditions to dynamically adjust frequency. The branch predictor detects potential loops caused by resource contention, and this feedback is used by the frequency selection module to adjust frequency accordingly, creating a closed-loop control system that efficiently manages resource waiting without excessive complexity.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10303482B2Dynamic processor frequency selection

Publication Date: 2019.05.28 RED HAT INC

AI summary

A dynamic processor frequency selection system includes a memory and a processor in communication with the memory. The processor includes a dynamic processor frequency selection module, a branch predictor module, a measurement module, and a power module. The measurement module measures a value according to a looping prediction function, which represents a quantity of cycles spent waiting for a type of contended resource within an instruction sequence. Additionally, the processor retains the value and branch history information, which is used to predict a waiting period associated with a potential loop. Then, the dynamic processor frequency selection module predicts the potential loop in a subsequent instruction according to the type of contended resource. The power module dynamically reduces a processor frequency during the waiting period from a first frequency state to a second frequency state according to the potential loop prediction. Then, the processor resumes operation at the first frequency state.