System and method for managing a memory hierarchy

A computer system comprising:

• a processor and a first memory for the processor;
• and
• a device coupled to the processor and including a cache and a second memory,
• wherein the device is configured to:
• observe, over a first period of time, accesses to pages of the first memory;
• determine that no page in a first group of pages of the first memory was accessed during the first period of time;
• and
• in response to determining that no page in the first group of pages was accessed during the first period of time, move each page in the first group of pages from the first memory to the second memory, and
• wherein the processor is configured to:
• generate a count of pages accessed during the first period of time in other groups of pages of the first memory;
• and
• in response to determining that the page count is less than a threshold number of pages, move each page in a second group of pages that was not accessed during the first period of time from the first memory to the second memory, wherein the second group of pages is one of the other groups of pages and includes at least one page which was not accessed during the first period of time and at least one page which was accessed during the first period of time.

A non-transitory computer readable medium comprising instructions for carrying out a method for managing a memory hierarchy including a first memory and a second memory that is at a lower position in the memory hierarchy than the first memory, the method comprising:

• observing, over a first period of time, accesses to pages of the first memory;
• determining that no page in a first group of pages of the first memory was accessed during the first period of time;
• in response to determining that no page in the first group of pages was accessed during the first period of time, moving each page in the first group of pages from the first memory to the second memory;
• generating a count of pages accessed during the first period of time in other groups of pages of the first memory;
• and
• in response to determining that the page count is less than a threshold number of pages, moving each page in a second group of pages that was not accessed during the first period of time from the first memory to the second memory, wherein the second group of pages is one of the other groups of pages and includes at least one page which was not accessed during the first period of time and at least one page which was accessed during the first period of time.