System and method for reference and modification tracking

A method for propagating reference and modification bit values into a translation table comprising:

• issuing a write instruction including a virtual address;
• translating the virtual address to a corresponding physical address in a corresponding entry in a table lookaside buffer including:
• determining the selected virtual address is not within a reach of the table lookaside buffer entry that is currently loaded in the table lookaside buffer;
• if one of a plurality of base and bounds register entries includes the selected virtual address, then identifying one of the plurality of the base and bounds register entries that includes the selected virtual address;
• calculating a new table lookaside buffer entry that includes the selected virtual address;
• and
• loading the new table lookaside buffer entry in the table lookaside buffer;
• writing data to the corresponding physical address;
• setting at least one of a reference bit value or a modification bit value in the corresponding entry in the table lookaside buffer;
• analyzing the table lookaside buffer to identify any set reference bit values and set modification bit values;
• updating a corresponding entry in a translation table for each one of the identified set reference bit values and the identified set modification bit values including:
• updating a corresponding entry in the base and bounds register for each one of the identified set reference bit values and the identified set modification bit values when an indication provided by the corresponding origin flag for each one of the identified set reference bit values and identified set modification bit values indicates the base and bounds register;
• updating a corresponding entry in the translation table for each one of the identified set reference bit values and the identified set modification bit values when the indication provided by the corresponding origin flag for each one of the identified set reference bit values and identified set modification bit values indicates the translation table;
• and
• resetting the identified set reference bit values and the identified set modification bit values in the table lookaside buffer.

A computer system comprising:

• a main memory;
• a processor die coupled to the main memory by a first bus, the processor die including a processor core coupled to a first cache memory and a plurality of base and bounds registers, each one of the plurality of base and bounds registers having a base virtual address field, an ending virtual address field and a base physical address field, the first cache memory having a table lookaside buffer stored therein, the table lookaside buffer including a plurality of table lookaside buffer entries, each one of the plurality of table lookaside buffer entries including an origin flag;
• logic for issuing a write instruction including a virtual address;
• logic for translating the virtual address to a corresponding physical address in a corresponding entry in a table lookaside buffer;
• logic for writing data to the corresponding physical address;
• logic for setting at least one of a reference bit value or a modification bit value in the corresponding entry in the table lookaside buffer;
• logic for analyzing the table lookaside buffer to identify any set reference bit values and set modification bit values;
• logic for updating a corresponding entry in a translation table for each one of the identified set reference bit values and the identified set modification bit values includes logic for determining an indication provided by a corresponding origin flag for each one of the identified set reference bit values and identified set modification bit values;
• and
• logic for resetting the identified set reference bit values and the identified set modification bit values in the table lookaside buffer.