Multithreading Capability Information Retrieval for Consistent Response Times

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Solution Overview

Problem

The variability in multithreading thread density on contemporary hardware platforms leads to inconsistent transaction response times and billing, as operating systems are unaware of whether they have exclusive control of a core or are sharing resources with other threads, resulting in unpredictable capacity provisioning and utilization.

Innovation Solution

A system and method that allows cores to be configurable between single thread and multithreading modes, enabling the execution of a retrieve multithreading capability information instruction to obtain and store thread identification information, thereby managing thread densities and optimizing resource utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If transparent multithreading operation is implemented without OS modification, then ease of operation is improved, but response time consistency deteriorates

Engineering Contradiction:
Improveease of operationVSAvoidresponse time consistency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces a feedback mechanism where the OS queries multithreading capability information from the hardware and adjusts thread density accordingly. The system provides feedback about actual thread execution status to the OS, enabling the OS to make informed decisions about thread scheduling and core allocation, thereby maintaining consistent response times while preserving ease of operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces a multithreading control facility as an intermediary between the hardware and the OS. This intermediary manages the complexity of multithreading operations, translating hardware capabilities into OS-manageable information while maintaining transparent operation. The control facility acts as a mediator that reconciles the conflict between transparent operation and consistent performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If high thread density is maintained to maximize MT capacity, then productivity is improved, but device complexity increases

Engineering Contradiction:
Improvecompute capacityVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent extracts the complexity of multithreading management from the OS and places it in a dedicated hardware control facility. By taking out the management complexity and isolating it in a specialized component, the system can maintain high thread density for maximum productivity while the OS interacts with a simplified interface, effectively reducing the perceived device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The multithreading control facility provides self-service by automatically managing thread density and core allocation based on hardware capabilities and OS queries. The system self-regulates to maintain optimal thread density without requiring complex OS intervention, thereby achieving high productivity while keeping the control mechanism relatively simple.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If dynamic thread density adjustment is implemented, then adaptability is improved, but measurement precision deteriorates

Engineering Contradiction:
ImproveadaptabilityVSAvoidcapacity measurement precision
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent implements preliminary action by having the OS query multithreading capability information in advance before executing workloads. The system prepares thread density configurations and core allocations beforehand based on hardware capabilities and workload characteristics. This preliminary setup enables dynamic adaptability during execution while maintaining precise measurement of available capacity through pre-determined thread density parameters.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3123327B1Multithreading capability information retrieval
Publication Date: 2019.05.15 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • EP3123327B1 patent drawingFigure 1A
  • EP3123327B1 patent drawingFigure 1B
  • EP3123327B1 patent drawingFigure 2

AI summary

Embodiments relate to multithreading capability information retrieval. An aspect is a computer system includes a configuration with one or more cores configurable between a single thread (ST) mode and a multithreading (MT) mode. The ST mode addresses a primary thread and the MT mode addresses the primary thread and one or more secondary threads on shared resources of each core. The computer system also includes a multithreading facility configured to control utilization of the configuration to perform a method that includes executing, by the core, a retrieve multithreading capability information instruction. The execution includes obtaining thread identification information that identifies multithreading capability of the configuration, and storing the obtained thread identification information.