Assume that on some computer the overhead of trapping to the

Assume that on some computer the overhead of trapping to the kernel for clock ticks is about 2 microseconds, with the handler requiring another 9 microseconds. Clock ticks typically occur at a frequency of 500Hz. What percentage of the CPU\'s time is devoted to the clock?

Solution

Given

overhead of trapping to the kernel for clock ticks = 2 microseconds

handler requiring = 9 microseconds

Total = 11 microseconds

CPU clock rate f = 500Hz = 500 cycles per second = 1/T

CPU time T = 1/500 seconds = 1000*1000/500 microseconds = 2000 microseconds

So percentage of the CPU\'s time is devoted to the clock = 11/2000*100 = 0.55%