Mapping a performance request to an operating frequency in a processor
In an embodiment, a processor includes multiple cores each to independently execute instructions and a power control unit (PCU) coupled to the plurality of cores to control power consumption of the processor. The PCU may include a mapping logic to receive a performance scale value from an operating system (OS) and to calculate a dynamic performance-frequency mapping based at least in part on the performance scale value. Other embodiments are described and claimed.
1. A processor comprising:
a plurality of cores each to independently execute instructions; and
a power control unit (PCU) coupled to the plurality of cores to control power consumption of the processor, the PCU including a mapping logic to receive a performance scale value from an operating system (OS) and to dynamically calculate a dynamic performance-frequency mapping based at least in part on the performance scale value and a workload scalability value for a workload to be executed on the processor, and a frequency control logic to dynamically determine a target operating frequency based at least in part on the dynamic performance-frequency mapping, the performance scale value and one or more processor constraints.
2. The processor of claim 1 , wherein the frequency control logic is to cause the processor to operate at the target operating frequency.
3. The processor of claim 1 , wherein the mapping logic is further to receive the target operating frequency and map the target operating frequency to a delivered performance scale value using the dynamic performance-frequency mapping.
4. The processor of claim 3 , wherein the mapping logic is to communicate the delivered performance scale value to the OS.
5. The processor of claim 1 , further comprising a non-volatile storage to store a table having a plurality of entries each to associate a performance scale value to an operating frequency, the table corresponding to a static performance-frequency mapping.
6. The processor of claim 5 , wherein the mapping logic is to communicate performance enumeration information to the OS.
7. The processor of claim 6 , wherein the performance enumeration information includes at least some of the plurality of entries of the table.
8. The processor of claim 1 , wherein the mapping logic is to receive a tolerance value, an energy performance bias, a first limit value and a second limit value from the OS.
9. The processor of claim 8 , wherein the frequency control logic is to adjust the determined target operating frequency based at least on one of the tolerance value and the first and second limit values.
10. The processor of claim 8 , wherein the frequency control logic is to determine the target operating frequency further based on the energy performance bias.
11. A non-transitory machine-readable medium having stored thereon instructions, which if performed by a machine cause the machine to perform a method comprising:
receiving a performance scale value corresponding to a performance request, limit values, and an energy performance bias value in a first logic of a processor;
calculating, in the first logic, a dynamic performance-frequency mapping based at least in part on a dynamic workload scalability factor and the performance scale value;
determining, in the first logic, a target operating frequency for at least a portion of the processor based on the performance scale value, the energy performance bias value and at least one processor constraint; and
determining if the target operating frequency is within the limit values, and if not, adjusting the target operating frequency to be within the limit values.
12. The non-transitory machine-readable medium of claim 11 , wherein the method further comprises communicating performance enumeration information including a plurality of performance scale values to an operating system (OS), and thereafter receiving the performance scale value from the OS.
13. The non-transitory machine-readable medium of claim 11 , wherein the method further comprises calculating a delivered performance scale value using the target operating frequency and the dynamic performance-frequency mapping, and reporting the delivered performance scale value to an operating system.
14. The non-transitory machine-readable medium of claim 11 , wherein the method further comprises determining the dynamic workload scalability factor based on a workload executing on the processor.
15. A system comprising:
a multicore processor including a plurality of cores and a power controller having a first logic to receive a performance scale value indicative of an operating system (OS)-requested performance level, the performance scale value one of a plurality of performance scale values communicated to the OS by the first logic, and to generate a dynamic performance-frequency mapping using the performance scale value, a scalability value and a static performance-frequency mapping, wherein the first logic is to communicate a delivered performance scale value at which the processor is to operate to the OS.
16. The system of claim 15 , wherein the first logic is to determine a target operating frequency based at least in part on the performance scale value and one or more processor constraints.
17. The system of claim 16 , wherein the first logic is to map the target operating frequency to the delivered performance scale value using the dynamic performance-frequency mapping.
18. The system of claim 15 , wherein the first logic is to obtain the plurality of performance scale values from a non-volatile storage having a table to associate each of the plurality of performance scale values with an operating frequency, the table corresponding to the static performance-frequency mapping.