Mixed cache management

A computing system, comprising:

• a processor;
• a mixed cache coupled to the processor and comprising a first cache region and a second cache region of different memory types, the mixed cache being indexed to a main memory comprising physical pages so that one group of contiguous cache sets in the mixed cache is mapped to a physical page of the main memory;
• a nursery array and a mature array indexed to a virtual memory comprising virtual pages so that each virtual page of the virtual memory is mapped to one row in the nursery array and one row in the mature array;
• wherein the processor is configured to control operation of:
• a page partition module to implement page coloring to map the virtual memory to the main memory so that physical pages mapped to different groups of contiguous cache sets are assigned to adjacent virtual pages;
• a sampler to record access to a particular virtual page from the mixed cache, the sampler being configured to:
• receive a virtual address for the particular virtual address access;
• from the received virtual address, determine an index and a tag of an array address to the nursery array and the mature array;
• follow the determined index of the array address to a row in the nursery array and a row in the mature array, the row in the nursery array and the row in the mature array comprising virtual page entries;
• determine whether or not the determined tag of the array address matches any tag in the virtual page entries of the row in the nursery array and the row in the mature array;
• in response to a non-match between the determined tag of the array address and any tag in the virtual page entries of the row in the nursery array and the row in the mature array, write a virtual page entry of the row in the nursery array with the determined tag of the array address and an access count;
• and
• in response to a match between the determined tag of the array address and the tag in the virtual page entry, increment the access count in the virtual page entry corresponding to the matched tags.

A non-transitory, computer-readable storage medium encoded with instructions executable by a processor to:

• apply page coloring to map a virtual memory comprising virtual pages to a main memory comprising physical pages so that physical pages mapped to different groups of contiguous cache sets in a mixed cache are assigned to adjacent virtual pages, the mixed cache being indexed to the main memory so each physical page in the main memory is mapped to one group of contiguous cache sets in the mixed cache;
• and
• record access to a particular virtual page of the virtual memory from the mixed cache, comprising to:
• receive a virtual address for the particular virtual page;
• from the received virtual address, determine an index and a tag of an array address to a nursery array and a mature array, the nursery array and the mature array being indexed to the virtual memory so each virtual page is mapped to one row in the nursery array and one row in the mature array;
• follow the determined index of the array address to a row in the nursery array and a row in the mature array, the row in the nursery array and the row in the mature array comprising virtual page entries;
• determine whether or not the determined tag of the array address matches any tag in the virtual page entries of the row in the nursery array and the row in the mature array;
• in response to a non-match between the determined tag of the array address and any tag in the virtual page entries of the row in the nursery array and the row in the mature array, write a virtual page entry of the row in the nursery array with the determined tag of the array address and an access count;
• and
• in response to a match between the determined tag of the array address and the tag in in the virtual page entry, incrementing the access count in the virtual page entry corresponding to the matched tags.