Clock calibration in a computing system using temperature sensors
Described herein are systems, methods, and software to manage time calibration associated with an oscillator of a computing system. In one example, a computing system monitors clock cycles for an oscillator on the computing system, receives timing messages from a server, and calculates the frequency of the oscillator at intervals based on the monitored clock cycles and timing messages. The computing system further identifies a temperature from a temperature sensor at each of the intervals and generates a function to demonstrate frequency of the oscillator versus temperatures from the temperature sensor based on the identified temperatures and frequencies at the intervals.
1. A method of operating a computing system to compensate for fluctuations in a frequency from an oscillator, the method comprising:
monitoring clock cycles for an oscillator at the computing system;
receiving timing messages from a second computing system;
calculating the frequency of the oscillator at a plurality of intervals based on the monitored clock cycles and the timing messages;
at each of the plurality of intervals, identifying a temperature associated with the computing system from a temperature sensor of the computing system;
generating a function to demonstrate the frequency of the oscillator as a function of the temperature from the temperature sensor based on the frequencies and the temperatures at the plurality of intervals;
after generating the function, identifying a first temperature from the temperature sensor;
determining a first frequency for the oscillator based on the function;
calculating a frequency error from the first frequency to an expected frequency; and
applying a compensation to the first frequency based on the frequency error.
2. The method of claim 1 , wherein the function comprises a third-degree polynomial function.
3. The method of claim 1 , wherein the timing messages comprise a plurality of messages received using network timing protocol (NTP).
4. The method of claim 1 , wherein the timing messages comprise a plurality of messages received using precision time protocol (PTP).
5. The method of claim 1 , wherein generating the function to demonstrate the frequency of the oscillator as a function of the temperature from the temperature sensor based on the frequencies and the temperatures at the plurality of intervals comprises generating a polynomial regression function using data points each corresponding to a frequency and a temperature at an interval of the plurality of intervals.
6. The method of claim 5 , wherein the polynomial regression comprises a third-degree polynomial.
7. The method of claim 1 further comprising:
identifying an expiration of a period following the application of the compensation;
in response to the expiration of the period, identifying a second temperature from the temperature sensor;
determining a second frequency for the oscillator based on the function;
calculating a second frequency error from the second frequency to the expected frequency; and
applying a second compensation to the second frequency based on the second frequency error.
8. The method of claim 1 further comprising:
selecting the temperature sensor from a plurality of temperature sensors based on the proximity of the plurality of temperature sensors to oscillator in the computing system.
9. The method of claim 1 , wherein the computing system comprises a server computing system in a data center.
10. A computing apparatus comprising:
a storage device;
a processing device operatively coupled to the storage device; and
program instructions stored on the storage device to compensate for fluctuations in a frequency of an oscillator in a computing system that, when executed by the processing device, direct the computing apparatus to:
monitor clock cycles for an oscillator at the computing system;
receive timing messages from a second computing system;
calculate the frequency of the oscillator at a plurality of intervals based on the monitored clock cycles and the timing messages;
at each of the plurality of intervals, identify a temperature associated with the computing system from a temperature sensor of the computing system;
generate a function to demonstrate the frequency of the oscillator as a function of the temperature from the temperature sensor based on the frequencies and the temperatures at the plurality of intervals;
after generating the function, identify a first temperature from the temperature sensor;
determine a first frequency for the oscillator based on the function;
calculate a frequency error from the first frequency to an expected frequency; and
apply a compensation to the first frequency based on the frequency error.
11. The computing apparatus of claim 10 , wherein the function comprises a third-degree polynomial function.
12. The computing apparatus of claim 10 , wherein the timing messages comprise a plurality of messages received using network timing protocol (NTP).
13. The computing apparatus of claim 10 , wherein the timing messages comprise a plurality of messages received using precision time protocol (PTP).
14. The computing apparatus of claim 10 , wherein generating the function to demonstrate the frequency of the oscillator as a function of the temperature from the temperature sensor based on the frequencies and the temperatures at the plurality of intervals comprises generating a polynomial regression function using data points each corresponding to a frequency and a temperature at an interval of the plurality of intervals.
15. The computing apparatus of claim 14 , wherein the polynomial regression comprises a third-degree polynomial.
16. The computing apparatus of claim 10 , wherein the program instructions further direct the computing apparatus to:
identify an expiration of a period following the application of the compensation;
in response to the expiration of the period, identify a second temperature from the temperature sensor;
determine a second frequency for the oscillator based on the function;
calculate a second frequency error from the second frequency to the expected frequency; and
apply a second compensation to the second frequency based on the second frequency error.
17. The computing apparatus of claim 10 , wherein the program instructions further direct the computing apparatus to:
select the temperature sensor from a plurality of temperature sensors based on the proximity of the plurality of temperature sensors to oscillator in the computing system.
18. The computing apparatus of claim 10 , wherein the computing system comprises a server computing system in a data center.
19. The computing apparatus of claim 10 , wherein the timing messages comprise a plurality of messages using pulse per second (PPS) time synchronization protocol.
20. A system comprising:
a timing server;
communicate timing messages to the computing system;
a computing system communicatively coupled to the timing server and configured to:
receive the timing messages;
monitor clock cycles for an oscillator at the computing system;
calculate the frequency of the oscillator at a plurality of intervals based on the monitored clock cycles and the timing messages;
at each of the plurality of intervals, identify a temperature associated with the computing system from a temperature sensor of the computing system;
generate a function to demonstrate the frequency of the oscillator as a function of the temperature from the temperature sensor based on the frequencies and the temperatures at the plurality of intervals;
after generating the function, identify a first temperature from the temperature sensor;
determine a first frequency for the oscillator based on the function;
calculate a frequency error from the first frequency to an expected frequency; and
apply a compensation to the first frequency based on the frequency error.