Dispatching interrupts in a multi-processor system based on power and performance factors
A multi-processor system handles interrupts using a power and performance status of each processor and a usage scenario of each processor. The power and performance status is indicated by factors that affect power consumption and processor performance. The system identifies one of the processors for handling an interrupt based on a weighted combination of the factors. Each factor is weighted based on a usage scenario for which the interrupt was generated. The system then dispatches the interrupt to the identified one of the processors.
1. A system for handling interrupts, comprising:
a plurality of processors;
an interrupt controller; and
a plurality of interrupt-generating devices, wherein the interrupt controller is operative to:
receive a power and performance status of each processor, the power and performance status indicated by a plurality of factors that affect power consumption and processor performance;
receive a request for an interrupt from one of the interrupt-generating devices, the interrupt being generated in a usage scenario of the system;
calculate a weighted combination of the factors for each processor, wherein each factor is weighted based on the usage scenario;
identify one of the processors for handling the interrupt based on the weighted combination calculated for each processor; and
dispatch the interrupt to the identified one of the processors.
2. The system of claim 1 , wherein the factors for each processor include a measurement of demand imposed by current tasks on computing resources of the processor.
3. The system of claim 1 , wherein the factors for each processor include a presence of a hard deadline imposed by current tasks on the processor.
4. The system of claim 1 , wherein the factors for each processor include whether the processor is enabled to receive interrupts.
5. The system of claim 1 , wherein the factors for each processor include a pending interrupt count of the processor.
6. The system of claim 1 , wherein the factors for each processor include a power on/off state of the processor and a power on/off state of a cluster containing the processor.
7. The system of claim 1 , wherein the factors for each processor include a power mode indicating an idle level of the processor.
8. The system of claim 1 , wherein the factors for each processor include a state of energy efficiency of the processor with respect to an operating frequency of the processor.
9. The system of claim 1 , wherein the interrupt controller is further operative to:
in response to the usage scenario for which latency in response time of the interrupt dominates power consumption, assign higher weights to the factors that correspond to higher performance of the processor.
10. The system of claim 1 , wherein the interrupt controller is further operative to:
in response to the usage scenario for which power consumption dominates latency in response time of the interrupt, assign higher weights to the factors that correspond to lower power consumption of the processor.
11. A method for handling an interrupt in a system including a plurality of processors, comprising:
receiving a power and performance status of each processor, the power and performance status indicated by a plurality of factors that affect power consumption and processor performance;
receiving a request for an interrupt from one of the interrupt-generating devices, the interrupt being generated in a usage scenario of the system;
calculating a weighted combination of the factors for each processor, wherein each factor is weighted based on the usage scenario;
identifying one of the processors for handling the interrupt based on the weighted combination of the factors; and
dispatching the interrupt to the identified one of the processors.
12. The method of claim 11 , wherein the factors for each processor include a measurement of demand imposed by current tasks on computing resources of the processor.
13. The method of claim 11 , wherein the factors for each processor include a presence of a hard deadline imposed by current tasks on the processor.
14. The method of claim 11 , wherein the factors for each processor include whether the processor is enabled to receive interrupts.
15. The method of claim 11 , wherein the factors for each processor include a pending interrupt count of the processor.
16. The method of claim 11 , wherein the factors for each processor include a power on/off state of the processor and a power on/off state of a cluster containing the processor.
17. The method of claim 11 , wherein the factors for each processor include a power mode indicating an idle level of the processor.
18. The method of claim 11 , wherein the factors for each processor include a state of energy efficiency of the processor with respect to an operating frequency of the processor.
19. The method of claim 11 , further comprising:
identifying the usage scenario as a process for which latency in response time of the interrupt dominates power consumption; and
assigning higher weights to the factors that correspond to higher performance of the processor.
20. The method of claim 11 , further comprising:
identifying the usage scenario as a process for which power consumption dominates latency in response time of the interrupt; and
assigning higher weights to the factors that correspond to lower power consumption of the processor.