Method for optimized representation of page table entries

#The present invention relates to methods and system for memory management in general, and to methods and systems for managing memory in pages, in particular.

#Intermediate storage elements are known in the art. A conventional computer system includes random access memory (RAM), which is used for uploading software objects, executing them and for storing data objects, used by the software objects.

#The RAM size is often limited. When the memory requirements exceed the RAM size, then the system can allocate a storage area on another storage element, such as a hard drive, and define this storage area as virtual memory, serving as an extension of the RAM. Data portions, which are not often used, can be stored in the virtual memory until the system retrieves them for further processing.

#The disclosed technique will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which:

#FIG. 1A is a representation of a memory page record string, representing a predetermined page size, which is known in the art;

#FIG. 1B is a representation of the memory page record string of FIG. 1A, representing a different memory page size;

#The present disclosure provides a novel page address and size representation, which dynamically addresses different size pages. According to one embodiment, a fixed length field contains both the address and size field of pages. The assigned length of this field is one bit longer than the length of the largest page address in the system. Applicant found that the address space in a selected page size is counter-proportional to the page size. For example, if the address space of a 2n page size is 2m, then the address space of a 2n+k is 2m−k. Hence, the total length of the page size and page address space remains constant, where the n and m are given.

#(n+k)+(m−k)=n+m=const

#Accordingly, the disclosed technique assigns a dynamic page address space according to a given page size. The page size is set in a string of sequential bits and is determined according to the smallest page size. For example, a page size sub-string having a length of zero (no bits) denotes the smallest page size in the system and a page size sub-string having a length of six bits denotes the seventh page size in the system. In an example, where the smallest page size is 8KB (213), then the seventh page size in the system is 512KB (219). One embodiment includes a separator sub-string, which in the following examples includes a single bit, of an opposite value than the ones denoting the page size.