Mapping Merge Buffer for L2P Table Latency Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In memory systems, particularly non-volatile NAND devices, the loading of a logical-to-physical (L2P) table into cache during random write operations introduces latency, impacting performance by delaying subsequent random read operations, as the updated table needs to be flushed to non-volatile memory and reloaded for access.
Innovation Solution
Implementing a mapping merge buffer to store a portion of the L2P table during random write operations, allowing it to be maintained for subsequent random read operations without the need for reloading, thereby reducing the time required for these operations and enhancing overall system performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the L2P table is loaded into cache during random write operations, then the mapping can be updated efficiently, but the subsequent random read operations experience increased latency due to the need to flush and reload the table
Solution Approach 1:
The L2P table is divided into multiple entries that can be selectively loaded into the buffer based on the logical address range being accessed. This allows the system to load only the necessary portion of the table rather than the entire table, reducing the time required for subsequent read operations while maintaining efficient write operation updates.
Solution Approach 2:
The system performs preliminary actions by loading the L2P table entries into the buffer before the random write operation completes. This preliminary loading ensures that when subsequent random read operations occur, the mapping information is already available in the buffer, eliminating the need to wait for flush and reload operations.
2Reliability
If the L2P table is flushed to non-volatile memory after updates, then data persistence is maintained, but the time required for subsequent random read operations increases due to the need to reload the table
Solution Approach 1:
The buffer acts as an intermediary between the volatile cache and the non-volatile memory storage. It temporarily stores the L2P table entries, allowing the system to maintain data persistence without immediately flushing to non-volatile memory. This intermediary buffer enables subsequent read operations to access mapping information quickly while still maintaining the reliability of persistent storage.
Solution Approach 2:
The system performs preliminary action by pre-loading L2P table entries into the buffer before they are needed for read operations. This eliminates the wait time that would otherwise occur when flushing and reloading the table, while the buffer ensures data persistence is maintained without immediate write-back to non-volatile memory.
3Ease of operation
If the entire L2P table is loaded into cache, then all mappings are immediately available for access, but the time required to load and update the table increases
Solution Approach 1:
Instead of loading the entire L2P table into the buffer, the system segments the table and loads only the necessary entries corresponding to the logical address range being accessed. This segmentation approach maintains ease of operation by providing immediate access to required mappings while significantly reducing the time required to load and update the table compared to loading the complete table.
Data Source
AI summary
Methods, systems, and devices for address mappings for random access operations are described. A portion of a L2P table may be loaded (e.g., to a buffer) upon receiving a write command (e.g., a random write command). In some instances, one or more entries (e.g., one or more mappings) included in the portion of the L2P table may be updated based on the write command. The portion of the L2P table may be maintained in the buffer during subsequent access operations, such as random read operations. The subsequent access operations may utilize the portion of the L2P table to access a memory device.