Clock sources in the kernel
 

Hello,

I have a 3.16.7 kernel running on a server machine. Below are the list of the clock sources available to the kernel. By default TSC is selected.

cat /sys/devices/system/clocksource/clocksource/available_clocksource
tsc refined-jiffies jiffies

But sometimes, i have observed that after reboots the order of the available_clocksource changes, where in refined-jiffies comes first and is selected as default. This causes a lot of time drifts and causes havoc in the system.

I know i can provide clocksource= parameter to the kernel at boot to select the specified clock source, but how does the order of the available clock sources change and what governs it ??