Parallel Compute Array Hazard Mitigation for Memory Access Ordering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing parallel processing architectures face challenges in efficiently handling vast and unstructured datasets due to unpredictable memory access times and hazards such as race conditions, leading to inefficiencies and increased execution times.
Innovation Solution
Implementing an array of compute elements with cycle-by-cycle control using wide control words generated by a compiler, which tag memory access operations with precedence information and monitor these operations to detect and mitigate hazards by holding data in access buffers before promotion, ensuring semantically correct operation ordering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If parallel processing is implemented to improve processing speed, then productivity increases, but hazards such as race conditions and unpredictable memory access times occur leading to reduced reliability
Solution Approach 1:
The compiler performs preliminary tagging of memory access operations with precedence information during code generation. This advance preparation allows the hazard detection logic to identify potential race conditions and ordering violations before execution occurs, enabling preventive measures to be taken without impacting parallel processing performance.
Solution Approach 2:
An access buffer is introduced as an intermediary component between compute elements and memory. This buffer holds data temporarily and allows hazard detection logic to monitor and control memory access operations, ensuring correct ordering and preventing race conditions while maintaining parallel execution flow.
2Reliability
If hazard detection and mitigation mechanisms are implemented to improve reliability, then execution accuracy increases, but device complexity increases due to additional monitoring and buffering components
Solution Approach 1:
The hazard detection mechanism leverages precedence information that is already embedded in the control words by the compiler. Rather than requiring complex external analysis or additional metadata structures, the system uses self-contained precedence tags within existing control flow information to detect hazards, reducing overall system complexity.
Solution Approach 2:
The access buffer serves multiple functions: it acts as a standard data buffer for memory access, provides hazard detection capability through monitoring of precedence information, and enables mitigation of detected hazards by controlling data promotion timing. This multi-functionality reduces the need for separate dedicated hazard detection hardware.
3Reliability
If memory access operations are monitored and data is held in access buffers to prevent hazards, then reliability improves, but execution time increases due to additional monitoring overhead
Solution Approach 1:
When no hazards are detected in the monitored memory access operations, the system skips detailed hazard analysis and allows data to be promoted from the access buffer without delay. This selective approach ensures that the monitoring overhead only impacts execution time when actual hazards are present, not during normal safe operation.
Solution Approach 2:
The hazard detection logic continuously monitors memory access operations and provides feedback about detected hazards to the control system. This feedback mechanism allows the system to dynamically adjust data promotion timing based on actual hazard conditions rather than applying conservative delays uniformly, optimizing execution time while maintaining reliability.
Data Source
AI summary
Techniques for parallel processing using hazard detection and mitigation are disclosed. An array of compute elements is accessed. Each compute element within the array of compute elements is known to a compiler and is coupled to its neighboring compute elements within the array of compute elements. Control for the compute elements is provided on a cycle-by-cycle basis. Control is enabled by a stream of wide control words generated by the compiler. Memory access operations are tagged with precedence information. The tagging is contained in the control words. The tagging is provided by the compiler at compile time. Memory access operations are monitored. The monitoring is based on the precedence information and a number of architectural cycles of the cycle-by-cycle basis. The tagging is augmented at run time, based on the monitoring. Memory access data is held before promotion, based on the monitoring.