Hybrid address translation
First Claim
1. A computer program product for implementing hybrid address translation, the computer program product comprising:
- a tangible, non-transitory storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising;
receiving a first address, the first address comprising an effective address referencing a location in a first address space in a computer system comprising a first page table comprising a hashed page table (HPT), and a second page table comprising a radix tree;
searching a segment lookaside buffer (SLB) for an SLB entry corresponding to the first address, the SLB comprising a plurality of SLB entries each comprising a respective type field and a respective address field, the plurality of SLB entries comprising a first entry comprising a first type field corresponding to a search of the first page table comprising the HPT, and a second entry comprising a second type field corresponding to a search of the second page table comprising the radix tree;
determining whether a value of the type field in the SLB entry corresponding to the first address corresponds to a search of the first page table comprising the HPT or a search of the second page table comprising the radix tree; and
searching one of the first and second page tables to determine an address translation for the first address based on the type field in the SLB entry corresponding to the first address by;
based on determining that the value of the type field corresponds to the search of the first page table comprising the HPT, searching the first page table comprising the HPT to determine a second address, the second address comprising a translation of the first address into a second address space; and
based on determining that the value of the type field corresponds to the search of the second page table comprising the radix tree, searching the second page table comprising the radix tree to determine the second address.
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Accused Products
Abstract
Embodiments of the invention relate to hybrid address translation. An aspect of the invention includes receiving a first address, the first address referencing a location in a first address space. The computer searches a segment lookaside buffer (SLB) for a SLB entry corresponding to the first address; the SLB entry comprising a type field and an address field and determines whether a value of the type field in the SLB entry indicates a hashed page table (HPT) search or a radix tree search. Based on determining that the value of the type field indicates the HPT search, a HPT is searched to determine a second address, the second address comprising a translation of the first address into a second address space; and based on determining that the value of the type field indicates the radix tree search, a radix tree is searched to determine the second address.
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Citations
15 Claims
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1. A computer program product for implementing hybrid address translation, the computer program product comprising:
a tangible, non-transitory storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising; receiving a first address, the first address comprising an effective address referencing a location in a first address space in a computer system comprising a first page table comprising a hashed page table (HPT), and a second page table comprising a radix tree; searching a segment lookaside buffer (SLB) for an SLB entry corresponding to the first address, the SLB comprising a plurality of SLB entries each comprising a respective type field and a respective address field, the plurality of SLB entries comprising a first entry comprising a first type field corresponding to a search of the first page table comprising the HPT, and a second entry comprising a second type field corresponding to a search of the second page table comprising the radix tree; determining whether a value of the type field in the SLB entry corresponding to the first address corresponds to a search of the first page table comprising the HPT or a search of the second page table comprising the radix tree; and searching one of the first and second page tables to determine an address translation for the first address based on the type field in the SLB entry corresponding to the first address by; based on determining that the value of the type field corresponds to the search of the first page table comprising the HPT, searching the first page table comprising the HPT to determine a second address, the second address comprising a translation of the first address into a second address space; and based on determining that the value of the type field corresponds to the search of the second page table comprising the radix tree, searching the second page table comprising the radix tree to determine the second address. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A computer system for hybrid address translation, the system comprising:
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address translation logic; and a segment lookaside buffer (SLB), the system configured to perform a method comprising; receiving a first address, the first address comprising an effective address referencing a location in a first address space in a computer system comprising a first page table comprising a hashed page table (HPT), and a second page table comprising a radix tree; searching a segment lookaside buffer (SLB) for an SLB entry corresponding to the first address, the SLB comprising a plurality of SLB entries each comprising a respective type field and a respective address field, the plurality of SLB entries comprising a first entry comprising a first type field corresponding to a search of the first page table comprising the HPT, and a second entry comprising a second type field corresponding to a search of the second page table comprising the radix tree; determining whether a value of the type field in the SLB entry corresponding to the first address corresponds to a search of the first page table comprising the HPT or a search of the second page table comprising the radix tree; and searching one of the first and second page tables to determine an address translation for the first address based on the type field in the SLB entry corresponding to the first address by; based on determining that the value of the type field corresponds to the search of the first page table comprising the HPT, searching the first page table comprising the HPT to determine a second address, the second address comprising a translation of the first address into a second address space; and based on determining that the value of the type field corresponds to the search of the second page table comprising the radix tree, searching the second page table comprising the radix tree to determine the second address. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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Specification