Processing system implementing variable page size memory organization using a multiple page per entry translation lookaside buffer
View Patent ↗A processing system includes memory management software responsive to changes in a page table to consolidate a run of contiguous page table entries into a page table entry having a larger memory page size. The memory management software determines whether the run of contiguous page table entries may be cached using the larger memory page size in an entry of a translation lookaside buffer. The translation lookaside buffer may be a MIPS-like TLB in which multiple page table entries are cached in each TLB entry.
1. A method for managing memory of a processing system comprising:
detecting a change in a page table including a plurality of page table entries, where each of the plurality of page table entries includes information for translating a virtual address to a corresponding physical address;
responding to the detection by identifying a run of contiguous page table entries having substantially the same access permission information;
analyzing the run of contiguous page table entries to determine whether those run may be consolidated using a larger memory page size, Y, and whether the run of contiguous page table entries may be consolidated for caching in an entry of a TLB that caches multiple page table entries, X, in a single TLB entry; and
updating an entry of the TLB with information corresponding to the run of contiguous page table entries when the analysis determines that the run of contiguous page table entries may be consolidated for caching in the entry of the TLB, where the updating uses the larger memory page size, Y.
2. The method of claim 1 , where the analysis comprises determining whether the run of contiguous page table entries can support a larger page size of X*Y.
3. The method of claim 1 , where the analysis comprises determining whether the virtual address corresponding to the run of contiguous page table entries is a multiple of Z pursuant to determining whether the run may be cached in an entry of the translation lookaside buffer, where Z=X*Y.
4. The method of claim 1 , where the memory page size management software consolidates the run of contiguous page table entries based on memory boundary conditions for the run of contiguous page table entries.
5. The method of claim 1 , where the memory page size management software consolidates the run of contiguous page table entries based on memory boundary conditions for the run of contiguous page table entries.
6. A processing system comprising:
a page table including a plurality of page table entries, where each of the plurality of page table entries includes information for a translating a virtual address page to a corresponding physical address page;
a translation lookaside buffer adapted to cache page table information, where each entry of the translation lookaside buffer caches information for multiple page table entries, X; and
memory management software responsive to changes in the page table to consolidate a run of contiguous page table entries into one or more page table entries having a larger memory page size, Y, and where the memory management software further determines whether the run of contiguous page table entries may be cached in an entry of the translation lookaside buffer; and
where the memory management software limits checking for contiguous page table entries to page table entries that are locally proximate page table entries that have been changed in the page table, deleted from the page table, and/or added to the page table, where the change, deletion, and/or addition corresponds to the change in the page table to which the memory management software has responded to make the check.
7. The processing system of claim 6 , where the memory management software updates an entry of the translation lookaside buffer using the larger memory page size, Y, if the memory management software determines that the run of contiguous page table entries may be cached in the entry of the translation lookaside buffer.
8. The processing system of claim 6 , where the memory management software consolidates the run of contiguous page table entries based on access permissions for the run of contiguous page table entries.
9. The processing system of claim 6 , where the memory management software determines whether the run of contiguous page table entries can support a memory page size of X*Y pursuant to determining whether the run may be cached in an entry of the translation lookaside buffer.
10. The processing system of claim 6 , where the memory management software determines whether the virtual address corresponding to the run of contiguous page table entries is a multiple of Z pursuant to determining whether the run may be cached in an entry of the translation lookaside buffer, where Z=X*Y.
11. The processing system of claim 6 , where the memory management software consolidates the run of contiguous page table entries based on memory boundary conditions for the run of contiguous page table entries.
12. The processing system of claim 6 , where the memory management software organizes the page table entries of the page table so that consecutive page table entries may be accessed to fill a single TLB entry.
13. The processing system of claim 6 , where the memory management software comprises translation lookaside miss software, where the translation lookaside miss software accesses consecutive page table entries to fill a single TLB entry, and where the number of consecutive page table entries is equal to X.
14. The processing system of claim 6 , where X=2.
15. A memory management system comprising:
a physical memory comprising memory management software, where the memory management software comprises:
page table management software adapted to manage a page table including a plurality of page table entries, where each of the plurality of page table entries includes information for translating a virtual address page to a corresponding physical address page;
translation lookaside buffer management software adapted to manage a translation lookaside buffer, where each entry of the translation lookaside buffer caches information for multiple page entries, X;
memory page size management software responsive to changes in the page table to consolidate a run of contiguous page table entries into one or more page table entries having a larger memory page size, Y, and where the memory page size management software further determines whether the run of contiguous page table entries may be cached in an entry of the translation lookaside buffer; and
where the memory page size management software limits checking for contiguous page table entries to page table entries that are locally proximate page table entries that have been changed in the page table, deleted from the page table, and/or added to the page table, where the change, deletion, and/or addition corresponds to the change in the page table to which the memory management software has responded to make the check.
16. The memory management system of claim 15 , where the translation lookaside buffer management software updates an entry of the translation lookaside buffer using the larger memory page size, Y, if the memory page size management software determines that the run of contiguous page table entries may be cached in the entry of the translation lookaside buffer.
17. The memory management system of claim 15 , where the memory page size management software consolidates the run of contiguous page table entries based on access permissions for the run of contiguous page table entries.
18. The memory management system of claim 15 , where the memory page size management software determines whether the run of contiguous page table entries can support a memory page size of X*Y pursuant to determining whether the run may be cached in an entry of the translation lookaside buffer.
19. The memory management system of claim 15 , where the memory page size management software determines whether the virtual address corresponding to the run of contiguous page table entries is a multiple of Z pursuant to determining whether the run may be cached in an entry of the translation lookaside buffer, where Z=X*Y.
20. The memory management system of claim 15 , where the memory page size management software consolidates the run of contiguous page table entries based on memory boundary conditions for the run of contiguous page table entries.
21. The memory management system of claim 15 , where the memory page size management software organizes the page table entries of the page table so that consecutive page table entries may be accessed to fill a single TLB entry.
22. The memory management system of claim 15 , further comprising translation lookaside miss software, where the translation lookaside miss software accesses consecutive page table entries to fill a single TLB entry, and where the number of consecutive page table entries is equal to X.