Adjusting page sharing scan rates based on estimation of page sharing opportunities within large pages

A non-transitory computer-readable storage medium comprising instructions, which when executed in a computer system having memory that is partitioned and accessed as large physical pages and small physical pages, causes the computer system to carry out the steps of:

• scanning at least one context for duplicated small virtual pages at a configurable page scan rate, wherein each of the at least one context has a virtual memory divided into a plurality of small virtual pages that are mappable to the physical pages;
• statistically estimating a percentage of small virtual pages mapped to large physical pages that are shareable while performing small virtual page scanning operations at a first page scan rate;
• and
• determining that the amount of free physical memory has decreased below a high memory threshold and, in response thereto, determining a second page scan rate based on the percentage of small virtual pages mapped to large physical pages that are shareable and performing small virtual page scanning operations at the second page scan rate instead of the first page scan rate.

A computer system comprising:

• a physical memory that is partitioned and accessed as large physical pages and small physical pages;
• at least one context, each of which having a virtual memory divided into a plurality of small virtual pages that are mappable to the physical pages;
• and
• a memory sharing module configured to identify identical small virtual pages, wherein the memory sharing module is configured to:
• scan each of the at least one context for duplicated small virtual pages at a configurable page scan rate;
• statistically estimate a percentage of small virtual pages mapped to large physical pages that are shareable while performing small virtual page scanning operations at a first page scan rate;
• and
• determine that the amount of free physical memory has decreased below a high memory threshold and, in response thereto, determine a second page scan rate based on the percentage of small virtual pages mapped to large physical pages that are shareable and perform small virtual page scanning operations at the second page scan rate instead of the first page scan rate.