Spin Loop Delay Instruction for Thread Balancing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In computing environments, spin loops that wait for asynchronous events to complete can resource-hog and disrupt thread balancing, as they continue to test conditions without making progress, affecting performance and making debugging difficult.
Innovation Solution
The Spin Loop Delay instruction is introduced, which delays the dispatch of an instruction until specified conditions are met or a timeout is reached, allowing other threads to utilize resources and preventing the pipeline from being flooded with idle instructions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spin loop continuously tests conditions to wait for asynchronous events, then the thread can detect when conditions are met, but the thread hogs resources and disrupts thread balancing
Solution Approach 1:
The patent extracts the harmful spin loop behavior from the thread execution by introducing a dedicated delay instruction that stalls the thread in a controlled manner. Instead of continuously executing test instructions that consume resources, the thread executes a single delay instruction that blocks resource usage while maintaining condition monitoring capability, thereby separating the waiting function from resource-consuming operations.
Solution Approach 2:
The patent changes the execution parameter of the waiting thread by introducing a timeout value parameter. The delay instruction accepts a timeout parameter that controls how long the thread should wait before giving up and allowing other threads to execute. This parameter change transforms the infinite spin loop into a bounded waiting operation that respects system resource constraints.
2Reliability
If a spin loop continuously executes test instructions, then the thread can monitor conditions, but it takes resources away from other threads in the multi-threaded environment
Solution Approach 1:
The patent extracts the resource-consuming test instructions from the spin loop and replaces them with a single delay instruction. The delay instruction maintains the condition monitoring capability through its internal timeout mechanism while eliminating the continuous execution of test instructions that were consuming instruction buffer, streaming buffer, issue queue entries, and other processor resources.
Solution Approach 2:
The patent introduces a disposable delay instruction that is executed once and then discarded, replacing the persistent spin loop. This single-use instruction provides the necessary waiting functionality without the ongoing resource consumption of a continuous spin loop, effectively using a cheap, short-lived solution to replace an expensive, persistent one.
3Adaptability or versatility
If a spin loop executes many test instructions, then the thread can check multiple conditions, but debug is difficult since the spin loop takes up the last 256 instructions executed
Solution Approach 1:
The patent extracts the multiple condition checking functionality from the spin loop instructions and consolidates it into a single delay instruction with a timeout parameter. This extraction removes the 256 instructions that were occupying the trace array, making debugging easier while preserving the ability to monitor conditions through the timeout mechanism and associated condition flags.
Data Source
AI summary
A Spin Loop Delay instruction. The instruction has a field associated therewith that indicates one or more conditions to be checked. Dispatching of the instruction is initially delayed. The instruction is subsequently dispatched based on a timeout, provided the instruction has not been previously dispatched based on meeting at least one condition of the one or more conditions to be checked.