Identifying and tracking frequently accessed registers in a processor

A computing system for identifying and tracking frequently accessed registers in a processor of a computing system, comprising a memory storing computer executable instructions for the computing system, and a processor for executing the computer executable instructions, the computer executable instructions cause the processor to perform comprising:

• initiating, by an operating system of the computing system, the creation of a list of top accessed registers of a plurality of architected registers in the processor, wherein each of the plurality of registers comprises a corresponding register usage counter;
• initializing each of the plurality of register usage counters;
• starting a register usage monitoring mode;
• examining each of the plurality of the register usage counters, and updating the list of top accessed registers;
• stopping the register usage monitoring mode;
• and
• updating, a register file partition assignment when the list of top accessed registers is identified;
• wherein the examining each of the plurality of the register usage counters comprises:
• setting a current register counter of the list of top accessed registers to 0;
• incrementing the current register counter of the list of top accessed registers by one;
• periodically searching for a register having highest value of register usage counter from a plurality of registers not in the list of top accessed registers while each of the plurality of register usage counters is incremented when the corresponding register is accessed;
• checking if the register having highest value of register usage counter reaches or passes a predetermined threshold when the register is found;
• adding the register found from the plurality of registers not in the list of top accessed registers to the list of top accessed registers when the register having highest value of register usage counter reaches or passes the predetermined threshold, and exiting current searching period when the register having highest value of register usage counter does not reach the predetermined threshold;
• checking whether the list of top accessed registers reaches a predetermined maximum number of registers in the list of top accessed registers;
• and
• incrementing the current register counter of the list of top accessed registers and continuing periodic searching when the list of top accessed registers does not reach the predetermined maximum number of registers in the list of top accessed registers, and exiting the examining each of the plurality of the register usage counters when the list of top accessed registers reaches the predetermined maximum number of registers in the list of top accessed registers.

A computer program product for identifying and tracking frequently accessed registers in a processor of a computing system, comprising a non-transitory computer readable storage medium having computer executable instructions embodied therewith, when executed by the processor on the computing system, the computer executable instructions cause the processor to perform:

• initiating, by an operating system of the computing system, the creation of a list of top accessed registers of a plurality of architected registers in the processor, wherein each of the plurality of registers comprises a corresponding register usage counter;
• initializing each of the plurality of register usage counters;
• starting a register usage monitoring mode;
• examining each of the plurality of the register usage counters, and updating the list of top accessed registers;
• stopping the register usage monitoring mode;
• and
• updating, a register file partition assignment when the list of top accessed registers is identified;
• wherein the examining each of the plurality of the register usage counters comprises:
• setting a current register counter of the list of top accessed registers to 0;
• incrementing the current register counter of the list of top accessed registers by one;
• periodically searching for a register having highest value of register usage counter from a plurality of registers not on the list of top accessed registers while each of the plurality of register usage counters is incremented when the corresponding register is accessed;
• checking if the register having highest value of register usage counter reaches or passes a predetermined threshold when the register is found;
• adding the register found from the plurality of registers not in the list of top accessed registers to the list of top accessed registers when the register having highest value of register usage counter reaches or passes the predetermined threshold, and exiting current searching period when the register having highest value of register usage counter does not reach the predetermined threshold;
• checking whether the list of top accessed registers reaches a predetermined maximum number of registers in the list of top accessed registers;
• and
• incrementing the current register counter of the list of top accessed registers and continuing periodic searching when the list of top accessed registers does not reach the predetermined maximum number of registers in the list of top accessed registers, and exiting the examining each of the plurality of the register usage counters when the list of top accessed registers reaches the predetermined maximum number of registers on the list of top accessed registers.