Memory QoS Manager for Tenant SLA Bandwidth Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing memory system Quality of Service (QoS) mechanisms are inadequate in managing memory bandwidth and latency for diverse computing devices and tenants in cloud environments, particularly with the emergence of alternate attachment means like CXL connections and multitenancy, necessitating a destination-based throttling scheme.
Innovation Solution
Implementing a memory request and QoS manager that tracks memory requests using globally unique tenant IDs, manages bandwidth and latency through a tenant registrar, resource monitor, and QoS enforcer, ensuring compliance with Service Level Agreements (SLAs) by prioritizing and throttling requests based on tenant-specific requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If source-based throttling is used to manage memory QoS, then memory bandwidth and latency can be controlled for traditional CPU access patterns, but the system cannot effectively manage memory access from alternate devices like CXL-attached accelerators and FPGAs that do not go through processor queues
Solution Approach 1:
The patent inverts the traditional source-based throttling approach by implementing destination-based throttling at the memory controller. Instead of controlling memory access at the CPU/processor queues (source), the system now enforces QoS policies at the memory controller (destination), where all memory requests converge regardless of their origin. This allows effective management of both traditional CPU access and alternate devices like CXL-attached accelerators and FPGAs.
Solution Approach 2:
The memory controller is enhanced with universal QoS management capabilities that handle multiple types of requesting devices through a unified interface. The system uses a common requestor ID field in memory requests to identify and apply QoS policies for diverse devices including CPUs, CXL accelerators, FPGAs, and other memory accessors, making the QoS mechanism adaptable to various attachment means while maintaining centralized control.
2Adaptability or versatility
If centralized QoS management at the memory controller is implemented, then destination-based throttling can be achieved for all memory requests, but system complexity increases due to additional tracking and enforcement mechanisms
Solution Approach 1:
The system implements self-service mechanisms where the QoS manager autonomously monitors memory request patterns, tracks bandwidth consumption per requestor ID, and dynamically adjusts throttling policies without requiring external intervention. The memory controller automatically enforces QoS decisions by controlling queue entry allocation based on real-time monitoring data, reducing the need for complex external management infrastructure.
Solution Approach 2:
The QoS management system incorporates continuous feedback loops where the monitoring component tracks memory request patterns and bandwidth consumption, feeds this information back to the QoS manager, which then adjusts throttling policies accordingly. This closed-loop control enables adaptive QoS management that responds to changing system conditions while maintaining manageable complexity through automated decision-making.
3Productivity
If queue entries are limited at the CPU to throttle memory access, then memory bandwidth can be controlled, but this approach fails when memory traffic originates from devices that bypass processor queues
Solution Approach 1:
The patent extracts the QoS enforcement function from the CPU/processor queues and relocates it to the memory controller. By removing the throttling logic from the source (CPU) and placing it at the destination (memory controller), the system ensures that all memory requests—whether from traditional CPU access or alternate devices like CXL accelerators—are subject to the same QoS policies. The memory controller independently manages queue entry allocation without relying on CPU-based throttling mechanisms.
Data Source
AI summary
A memory request manager in a memory system registers a tenant for access to a plurality of memory devices, registers one or more service level agreement (SLA) requirements for the tenant for access to the plurality of memory devices, monitors usage of the plurality of memory devices by tenants, receives a memory request from the tenant to access a selected one of the plurality of memory devices, and allows the access when usage of the plurality of memory devices meets the one or more SLA requirements for the tenant.