Flash Memory Buffer Management for Write Amplification Reduction
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Solution Overview
Problem
The inefficiency in reading and writing operations and the short service life of embedded multimedia cards (eMMC) using non-linear flash memory, due to mismatched page and block sizes, leading to increased write amplification and reduced performance.
Innovation Solution
A method and apparatus that dynamically adjust the buffer data area based on the actual physical block size of the flash memory, allowing for unified reading and writing operations by dividing and buffering data accordingly, and identifying dirty data for timely write operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the eMMC driver uses uniform 512-byte physical blocks for compatibility with different manufacturers and types, then the eMMC protocol compatibility is improved, but the flash memory reading and writing efficiency deteriorates due to write amplification
Solution Approach 1:
The patent segments the buffer data area into multiple pages, each page corresponding to the flash memory's physical block size. The buffer management system divides and manages data in page-sized units rather than uniform 512-byte blocks, allowing the host layer to align with the flash memory's native page structure while maintaining eMMC protocol compatibility at the block device layer.
Solution Approach 2:
The patent introduces dynamic buffer management where the buffer data area size and page alignment are adjusted based on the actual flash memory characteristics. The system dynamically determines the number of pages and their sizes according to the flash memory's physical block size, rather than using fixed uniform blocks, thereby optimizing read/write operations for the specific flash memory device.
2Device complexity
If the eMMC driver uses uniform 512-byte physical blocks, then the device complexity is reduced through standardization, but the service life of the flash memory deteriorates due to increased write amplification
Solution Approach 1:
The patent segments the buffer into page-aligned units that match the flash memory's physical structure. By managing data in page-sized segments rather than forcing uniform 512-byte blocks, the system reduces unnecessary write amplification and erase operations, thereby extending flash memory service life while maintaining driver standardization through the buffer abstraction layer.
Solution Approach 2:
The buffer data area acts as an intermediary between the eMMC protocol layer and the flash memory physical layer. It translates between the standardized 512-byte block interface and the flash memory's native page structure, allowing the driver to remain standardized while the buffer optimizes operations for flash longevity by aligning with physical block boundaries.
3Ease of operation
If the buffer data area is not aligned with the flash memory page size, then the ease of operation is improved through simplified uniform block handling, but the productivity deteriorates due to write amplification factors
Solution Approach 1:
The patent segments the buffer data area into pages that align with flash memory block sizes. This segmentation allows the system to maintain simple uniform block handling at the eMMC interface while internally organizing data in page-aligned segments, thereby eliminating write amplification issues without sacrificing operational simplicity for the host system.
Solution Approach 2:
The patent introduces a new dimension of buffer management by adding page-level organization between the block device layer and the flash memory physical layer. This additional organizational dimension allows uniform block handling to be maintained at one level while achieving page-aligned efficiency at another level, resolving the contradiction between simplicity and performance.
Data Source
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AI summary
The present invention relates to a method and an apparatus for reading/writing data from/into a flash memory, and user equipment. The method includes: receiving a read data instruction, where the read data instruction includes: a size of to-be-read data and a physical address of the to-be-read data in the flash memory; searching a buffer for the physical address; when the physical address is not found in the buffer, dividing a buffer data area from internal memory according to the size of the to-be-read data and an actual physical block size of the flash memory; and reading the to-be-read data from the flash memory according to the physical address and buffering the to-be-read data into the buffer data area. Therefore, problems of low reading and writing efficiency of the flash memory and a short service life of the flash memory can be resolved.