Method and apparatus for cache write overlap handling
Embodiments of the present disclosure generally relate to a target device handling overlap write commands. In one embodiment, a target device includes a non-volatile memory and a controller coupled to the non-volatile memory. The controller includes a random accumulated buffer, a sequential accumulated buffer, and an overlap accumulated buffer. The controller is configured to receive a new write command, classify the new write command, and write data associated with the new write command to one of the random accumulated buffer, the sequential accumulated buffer, or the overlap accumulated buffer. Once the overlap accumulated buffer becomes available, the controller first flushes to the non-volatile memory the data in the random accumulated buffer and the sequential accumulated buffer that was received prior in sequence to the data in the overlap accumulated buffer. The controller then flushes the available overlap accumulated buffer, ensuring that new write commands override prior write commands.
1. A method of handling write overlap data streams, comprising:
receiving data to a controller in a sequence;
detecting a cache collision of the data;
classifying the data as overlap data, random data, or sequential data;
writing random data to a random buffer;
writing sequential data to a sequential buffer;
writing overlap data to an overlap buffer; and
emptying the overlap data buffer, wherein emptying the overlap data buffer comprises:
flushing the random data and the sequential data that were received prior to the overlap data in the sequence to a non-volatile memory, and
flushing the overlap data to the non-volatile memory.
2. The method of claim 1 , wherein detecting the cache collision comprises determining a logical block address range associated with the data overlaps with a logical block address range of data currently stored in the random buffer or the sequential buffer.
3. The method of claim 1 , wherein flushing the overlap data overwrites a portion of the random data or a portion of the sequential data flushed to the non-volatile memory.
4. The method of claim 1 , wherein classifying the received data as overlap data is based on the detected cache collision.
5. The method of claim 1 , wherein classifying the data as random data or sequential data is based on a locality detection.