Physical Address-Based Set Partitioning to Reduce Cache Conflicts
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Solution Overview
Problem
Existing graphics and display processing systems face challenges with cache conflicts, particularly in jumbo caches and small buffers, leading to inefficient use of cache space and high conflict rates.
Innovation Solution
Implement physical address (PA)-based set partitioning to allocate small buffers efficiently, embedding multiple set-associative caches without being limited by associativity, thereby reducing cache conflicts and conserving space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If physical address-based set partitioning is implemented to allocate small buffers efficiently, then cache conflict rate is reduced and cache space utilization is improved, but device complexity increases due to additional address mapping logic
Solution Approach 1:
The cache address space is segmented into multiple partitions based on physical address ranges. Each partition independently manages its own set-associative cache structures, allowing small buffers to be allocated to specific partitions without conflicting with other buffers. This segmentation eliminates cache conflicts while maintaining manageable complexity through modular partition management.
Solution Approach 2:
The patent introduces a new dimension of address mapping by adding partition index selection based on physical address ranges. Instead of traditional flat address mapping, the system uses multi-dimensional mapping where the physical address determines both the partition and the set index within that partition, reducing conflicts without proportionally increasing complexity.
2Productivity
If multiple set-associative caches are embedded without associativity limits, then cache space utilization for small buffers is optimized, but manufacturing complexity increases
Solution Approach 1:
The cache is divided into multiple independent set-associative partitions, each capable of handling small buffers independently. This segmentation allows efficient utilization of cache space for different buffer sizes and types while simplifying the manufacturing process by using standardized modular cache block designs that can be replicated across partitions.
Solution Approach 2:
The cache partitioning mechanism is designed to be universal, handling various buffer sizes and access patterns through the same physical address-based partitioning logic. This multi-functional approach optimizes cache space utilization for different workloads without requiring custom-manufactured cache structures for each case, thereby easing manufacturing complexity.
3Productivity
If physical address-based set partitioning is used to reduce cache conflicts, then processing efficiency for graphics and display operations is enhanced, but address translation overhead increases
Solution Approach 1:
The cache partitioning scheme uses physical addresses directly without requiring additional virtual-to-physical translation steps. By pre-organizing cache partitions based on physical address ranges, the system eliminates address translation overhead while maintaining high processing efficiency for graphics and display operations that already operate with physical addressing.
Data Source
AI summary
Aspects presented herein relate to methods and devices for data or graphics processing including an apparatus, e.g., a graphics processing unit (GPU). The apparatus may configure an address range in a cache. The apparatus may also obtain a request to access data in the cache, where the request to access the data includes an address in the cache that maps to a set index in a plurality of set indexes, where an address value for the set index corresponds to a portion of the address. Further, the apparatus may select an updated address value for the set index, where the updated address value is associated with an updated address within the address range, and the updated address value corresponds to a portion of the updated address. The apparatus may also allocate the data in the request to the updated address value for the set index.