Programmable Cache Mapping for Dynamic SLC Replacement Policies

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Solution Overview

Problem

Conventional cache replacement policies in computing systems fail to optimize cache memory allocation for different components with varying memory access patterns, leading to suboptimal performance and power management due to inconsistent caching decisions based on system state changes and client types.

Innovation Solution

A method for managing cache memory by monitoring system state and client-provided telemetric data to dynamically update a programmable mapping table, using allocation/replacement identifiers (ARIDs) and buffer types to tailor cache policies for specific client types and access patterns, incorporating client caching hints, a programmable mapping table, and an SLC policy manager to optimize cache utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single cache replacement policy is used for all clients, then device complexity is reduced, but cache memory utilization and performance deteriorate due to inability to optimize for different access patterns

Engineering Contradiction:
Improvecache replacement policy managementVSAvoidcache memory utilization
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent segments the cache replacement policy management by introducing client-type-specific policies. Different cache clients (e.g., CPU, GPU, video decoder) are divided into distinct client types, each with its own optimized replacement policy. This segmentation allows the system to tailor caching behavior to specific access patterns without requiring a single complex policy to handle all cases, thus improving cache memory utilization while keeping individual client policies relatively simple.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic cache replacement policies that can adapt to changing system conditions. The system monitors cache performance metrics and access patterns, then dynamically adjusts replacement policies based on current system state. This dynamic approach allows the cache to optimize for different client types and access patterns over time, improving overall cache memory utilization without requiring static complex configuration.

Inventive Principle:
Principle #15Dynamics

2Productivity

If cache memory size is increased to improve performance, then cache hit rate increases, but power consumption and cost increase due to larger cache capacity requirements

Engineering Contradiction:
Improvecache hit rateVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by implementing client-type-specific cache replacement policies that optimize cache behavior for each client's specific access patterns. Instead of uniformly increasing cache size for all clients, the system applies targeted replacement policies to different client types (CPU, GPU, video decoder, etc.). This allows the same cache capacity to serve multiple clients more efficiently, improving cache hit rates without proportionally increasing power consumption.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If conventional cache replacement policies are used, then implementation simplicity is maintained, but performance optimization deteriorates due to inability to handle varying memory access patterns of different components

Engineering Contradiction:
Improvecache policy implementationVSAvoidperformance optimization
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent segments cache management into client-type-specific policies, where each client type (CPU, GPU, video decoder, network adapter) has its own optimized replacement policy. This segmentation maintains implementation simplicity for each individual client while achieving performance optimization through targeted policies. The system administrator or operating system can configure policies per client type without needing to implement complex individual policies for each client instance.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS12511234B2Managing a programmable cache control mapping table in a system level cache
Publication Date: 2025.12.30 NVIDIA CORP
  • US12511234B2 patent drawing
  • US12511234B2 patent drawing
  • US12511234B2 patent drawing

AI summary

Various embodiments include techniques for managing cache memory in a computing system. The disclosed techniques include a cache policy manager that monitors activity of various components that access a common cache memory. The cache policy manager establishes cache rules that determine what data remains stored in cache memory and what data is removed from cache memory in order to make room for new data. As the activities of these components change over time, cache rules that work well for a previous activity profile may no longer work well for the current activity profile. Therefore, the cache policy manager dynamically modifies the cache rules as the activity profile changes in order to select cache rules at any given time that work well with the current activity profile. These techniques are advantageous over conventional approaches that employ static cache rules that work well only for specific activity profiles.