Reserving a storage area and building page frame table entries

摘要

In one embodiment, a computer-implemented method includes receiving a large frame area (LFAREA) request, including a request for a plurality of page frame table entries (PFTEs) to back a plurality of frames in an LFAREA of main memory. Each of the plurality of frames has one of a first size and a second size, where the second size is larger than the first size. The method further includes counting how many frames in the main memory have yet to be initialized and have one of the first size and the second size. A size needed for the plurality of PFTEs is calculated, based at least in part on the counting. A storage area is reserved for the plurality of PFTEs, by a computer processor, where a size of the storage area is the size calculated based at least in part on the counting.

主权项

1. A computer-implemented method, comprising: receiving a large frame area (LFAREA) request, comprising a request for a plurality of page frame table entries (PFTEs) to back a plurality of frames in an LFAREA of main memory, wherein each of the plurality of frames has one of a first size and a second size, the second size being larger than the first size; counting how many frames in the main memory have yet to be initialized and have one of the first size and the second size; calculating a size needed for the plurality of PFTEs, based at least in part on the counting, wherein calculating the size needed for the plurality of PFTEs comprises calculating a size of the LFAREA, and wherein calculating the size of the LFAREA comprises: receiving, in the LFAREA request, bounds for the size of the LFAREA; calculating a maximum size of the LFAREA based on the bounds; and determining the size of the LFAREA, based on a comparison between the counting and the maximum size of the LFAREA; and reserving, by a computer processor, a storage area for the plurality of PFTEs, wherein a size of the storage area is the size calculated based at least in part on the counting, and wherein reserving the storage area for the plurality of PFTEs comprises: scanning the main memory for available 1 MB frames for storing the PFTEs; marking, as part of the storage area for the plurality of PFTEs, a plurality of contiguous groups of available 1 MB frames found during the scanning; and establishing a reserved PFTE area descriptor for each contiguous group of the plurality of contiguous groups, wherein the reserved PFTE area descriptor for each contiguous group describes a start address and the number of frames in the contiguous group.