Recycling buffer pointers using a prefetch buffer

A method for managing buffer pointers that point to locations in an off-chip memory, the off-chip memory storing data units, the method comprising:

• retrieving, by a controller in an on-chip memory, a first buffer pointer from a free-list of unallocated buffer pointers in an off-chip buffer pointer memory;
• storing, by the controller, the first buffer pointer in the on-chip prefetch buffer to obtain a quantity of buffer pointers in the on-chip prefetch buffer;
• determining, by the controller and in response to the storing the first buffer point in the on-chip prefetch buffer, whether the quantity of buffer pointers in the on-chip prefetch buffer exceeds a threshold;
• receiving, by the controller and when the quantity of buffer pointers in the on-chip prefetch buffer is determined to not exceed the threshold, a second buffer pointer from the off-chip memory;
• determining, by the controller and in response to receiving the second buffer pointer, whether the on-chip prefetch buffer is full, the on-chip prefetch buffer being to store buffer pointers;
• storing, by the controller, the second buffer pointer in the on-chip prefetch buffer when the on-chip prefetch buffer is determined not to be full;
• and
• storing, by the controller, the second buffer pointer in an off-chip buffer pointer memory when the on-chip prefetch buffer is determined to be full.

A network device comprising:

• an off-chip memory;
• and
• an on-chip controller that includes a prefetch buffer to store unallocated buffer pointers that point to available memory locations, the on-chip controller to:
• retrieve a first buffer pointer from the off-chip memory;
• store the first buffer pointer in the prefetch buffer to obtain a quantity of buffer pointers in the prefetch buffer;
• determine, in response to storing the first buffer point in the prefetch buffer, whether the quantity of buffer pointers in the prefetch buffer exceeds a threshold;
• receive, when the quantity of buffer pointers in the prefetch buffer is determined to not exceed the threshold, a second buffer pointer, from the off-chip memory, that points to an available location in the off-chip memory,
• determine, in response to receiving the second buffer pointer, whether the prefetch buffer is full,
• store the second buffer pointer in the prefetch buffer when the prefetch buffer is determined not to be full, and
• store the second buffer pointer in an off-chip memory when the prefetch buffer is determined to be full.