Pre-emptive storage strategies to reduce host command collisions

An apparatus comprising:

• a main non-volatile memory (NVM);
• a local memory;
• a command queue that lists pending data transfer commands received from a host device to transfer data between the NVM and the local memory, the pending data transfer commands comprising write commands to transfer, from the local memory to the NVM, host data received from the host device and read commands to transfer, from the NVM to the local memory and from the local memory to the host device, previously stored host data in the NVM;
• a collision manager configured to predict future collisions among the pending read commands in the command queue;
• and
• a storage manager which enacts a change in a storage policy associated with the NVM that reduces a future rate of the predicted future collisions responsive to a total number of the predicted future collisions exceeding a predetermined threshold, the change in the storage policy comprising performing a garbage collection operation upon a first garbage collection unit (GCU) in the NVM that uses a first set of resources by transferring a first set of valid data previously stored in the first GCU to a second GCU in the NVM that uses a different, second set of resources and transferring a second set of valid data previously stored in the first GCU to a third GCU that uses a different, third set of resources, erasing the first GCU, and storing selected write data associated with a selected pending write command to the first GCU.

A solid-state drive (SSD), comprising:

• a flash memory configured as a main memory store for a host device, the flash memory comprising a plurality of semiconductor dies accessed by an associated plurality of channels, the flash memory arranged into a plurality of garbage collection units (GCUs) each individually allocated and erased as a unit and each spanning a different combination of the semiconductor dies and the associated channels;
• a controller circuit configured to manage data transfers between the flash memory and the host device using a local memory and a command queue that lists pending data transfer commands comprising host write commands to write data to the flash memory and host read commands to retrieve previously written read data from the flash memory;
• a collision manager circuit configured to predict future collisions among the pending read commands in the command queue;
• and
• a storage manager circuit which enacts a change in a storage policy associated with the flash memory that reduces a future rate of the predicted future collisions by performing a garbage collection operation upon a first GCU in the NVM that uses a first set of resources by transferring a first set of valid data previously stored in the first GCU to a second GCU in the NVM that uses a different, second set of resources and transferring a second set of valid data previously stored in the first GCU to a third GCU that uses a different, third set of resources, erasing the first GCU, and storing selected write data associated with a selected pending write command to the first GCU, the change in the storage policy enacted responsive to a total number of the predicted future collisions exceeding a predetermined threshold.