Dynamic memory bandwidth shaping

A memory system comprising:

• a first memory and a second memory;
• the first memory configured as a cache for the second memory;
• a first bandwidth shaper configured to shape bandwidth for the second memory;
• a second bandwidth shaper configured to track hit bandwidth on the first memory;
• and
• the second bandwidth shaper configured to provide replenishments of bandwidth to the second memory to the first bandwidth shaper based on the hit bandwidth.

A system comprising:

• an upper memory of a memory hierarchy;
• a lower memory of the memory hierarchy;
• a bandwidth shaper comprising:
• an accumulator for bandwidth credit for a traffic class to access the lower memory;
• logic configured to:
• increment the accumulator at a rate based on a cycle time of the upper memory;
• decrement the accumulator by a set amount in response to a grant of bandwidth for the traffic class to the upper memory;
• apply a lower memory bandwidth replenishment signal for the traffic class to the accumulator, the replenishment signal based on a hit bandwidth of the traffic class on the upper memory;
• and
• generate, based on a value of the accumulator, a mask setting for the traffic class in a bandwidth arbiter of the upper memory.

A system comprising:

• an upper memory of a memory hierarchy;
• a lower memory of the memory hierarchy;
• a bandwidth shaper comprising:
• an accumulator for hit bandwidth credit for a traffic class on the upper memory;
• logic configured to:
• increment the accumulator at a rate based on a cycle time of the upper memory;
• decrement the accumulator in response to a hit on the upper memory by the traffic class;
• and
• in response to the hit on the memory by the traffic class, and on condition that the accumulator has not reached a value indicating a violation of a configured limit on the hit bandwidth for the traffic class, generate a replenishment signal for the traffic class to a bandwidth shaper of traffic between the upper memory and the lower memory.