Memory-centric page table walker
AssigneeInternational Business Machines Corporation
InventorsSumedh W. Sathaye, Gordon Taylor Davis
Life of this patent
Estimating the term…
Abstract
The page table walker is moved from its conventional location in the memory management unit associated with the data processor to a location in main memory i.e. the main memory controller. As a result, an implementation is provided wherein the processing of requests for data could selectively avoid or bypass cumbersome caches associated with the data processor.
Claims7
A computer system comprising:
- at least one data processor unit connected to a main memory;
- each of said at least one data processor units comprising:
- a memory management unit for controlling the conversion of an address of requested data received from a processor into a physical address of said requested data;
- a data cache for storing recently requested data;
- a translation unit in said memory management unit for checking received data requests against data stored in said data cache;
- and
- a connector for bypassing said data cache;
- said main memory comprising:
- storage for the data being accessed in pages at said physical addresses;
- a page table accessed by said memory management unit for converting to said page addresses;
- a random access memory (RAM);
- and
- a memory controller for controlling said RAM, wherein said memory controller includes a page table walker for proceeding through the entries on said page table;
- wherein a data request is connected directly to said page table walker in the memory controller, via said connector for bypassing said data cache, for address conversion;
- wherein said translation unit determines if the data cache is to be bypassed based upon a flag in the address of the requested data.
In a computer system comprising at least one data processor unit connected to a main memory, a method for converting an address of requested data received from a processor into a physical address of said requested data, the method comprising:
- storing the data being accessed in pages at said physical address in said main memory;
- and
- converting said address of requested data into said physical address using a page table stored in said main memory including steps of proceeding through entries on said page table using a page table walker stored in said main memory;
- storing recently requested data in a cache,
- checking received data requests against data stored in said cache, and
- enabling the bypassing of said cache wherein a data request may be connected directly to said page table walker in said memory controller for address conversion;
- determining, based upon a flag in an address of the data request, whether the data request requires the checking of said data in said cache or whether the data request bypasses said cache and is connected directly to page table walker for conversion.
Dependencies are inferred from the claim text.