Storage Controller Linked-List L2P Tracking for Lower SRAM Use
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing storage technologies face challenges in efficiently managing logical to physical (L2P) tables and their metadata, leading to high overhead in static random access memory (SRAM) usage.
Innovation Solution
A storage controller employs a comparison-based dirty L2P table counter that compares newly inserted logical page numbers with previous and next nodes in a doubly-linked or single-linked list structure, incrementing the counter only when differences are detected, thereby reducing SRAM requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the L2P table and metadata are stored in SRAM, then fast access and efficient L2P table management are achieved, but SRAM capacity requirements and overhead increase significantly
Solution Approach 1:
The L2P table is divided into multiple segments or pages, where only the actively used segments are maintained in SRAM. The segmentation allows the system to split the large L2P table into manageable portions, reducing the SRAM capacity needed while maintaining fast access for current operations. Metadata is also segmented and stored only when necessary.
Solution Approach 2:
The system performs preliminary actions by pre-loading only the necessary L2P table segments into SRAM before they are needed for mapping operations. This allows the system to maintain a smaller SRAM footprint while ensuring that required mapping data is available when needed, balancing speed requirements with capacity constraints.
2Measurement precision
If the dirty L2P table counter tracks all L2P table modifications, then accurate metadata update tracking is achieved, but comparison overhead and processing time increase
Solution Approach 1:
The invention extracts only the essential comparison information needed for dirty L2P table detection, rather than performing full L2P table comparisons. By taking out only the critical metadata fields or summary indicators for comparison, the system achieves accurate tracking of modifications without the time overhead of comprehensive table comparisons.
Solution Approach 2:
The system performs partial comparisons by checking only specific critical fields or summary metadata of the L2P table rather than comparing entire tables. This partial action approach provides sufficient accuracy for detecting dirty states while significantly reducing the processing time and computational overhead associated with full table comparisons.
3Ease of manufacture
If nodes are inserted between existing nodes in a linked list structure, then L2P table updates are efficiently managed, but memory allocation complexity and overhead increase
Solution Approach 1:
The invention merges the node structure with the linked list framework, where each node in the list represents an L2P table entry. By combining the data storage and structural organization into a unified node-based approach, the system simplifies memory allocation and update operations. Nodes can be efficiently inserted between existing nodes to reflect L2P table modifications without requiring separate allocation mechanisms.
Solution Approach 2:
The node structure serves multiple functions simultaneously: it stores L2P mapping data, maintains linked list connectivity, and enables efficient insertion and deletion operations. This multi-functional design reduces memory allocation complexity by using a single versatile data structure rather than requiring separate mechanisms for data storage and structural management.
Data Source
AI summary
An example method of operating a storage controller that stores one or more logical to physical (L2P) tables includes receiving a request to modify a first logical page number (LPN) from a host, inserting a first node corresponding to the first LPN between a second node related to a second LPN and a third node corresponding to a third LPN, and determining whether a first L2P table is the same as a second L2P table based on a number of pages in an L2P table of the one or more L2P tables. The first L2P table includes the first LPN. The second L2P table includes the second LPN.