Process-specific views of large frame pages with variable granularity

摘要

The page tables in existing art are modified to allow virtual address resolution by mapping to multiple overlapping entries, and resolving a physical address from the most specific entry. This enables more efficient use of system resources by allowing smaller frames to shadow larger frames. A page table is selected. When a virtual address in a request corresponds to an entry in the page table, which identifies a next page table associated with the large frame, a determination is made that the virtual address corresponds to an entry in the next page table, the entry in the next page table referencing a small frame overlay for the large frame. The virtual address is mapped to a physical address in the small frame overlay using data of the entry in the next page table. The physical address in a process-specific view of the large frame is returned.

主权项

1. A computer implemented method for using a large frame, the computer implemented method comprising:
selecting a page table, wherein the page table references data stored in a physical memory associated with a data processing system; determining, using a processor in the data processing system, whether a virtual address in a request corresponds to an entry in the page table; determining, responsive to the virtual address corresponding to the entry in the page table, that the entry in the page table identifies a next page table associated with the large frame, wherein the large frame is a page of the data in the memory such that a size of the page exceeds a threshold size; determining that the virtual address corresponds to an entry in the next page table, the entry in the next page table referencing a small frame overlay for the large frame, wherein the small frame is a second page of data in the memory such that the size of the second page does not exceed the threshold size; mapping the virtual address to a physical address in the small frame overlay using data of the entry in the next page table; and returning, responsive to the request, the physical address in a process-specific view of the large frame.