Tick, jiffies and time interpolation

Kirilla · 02-27-2009, 03:15 AM

Hi.

I'm a little bit confused with kernel synchronization. Can somebody explain the relation between tick, jiffy, timers and time interpolation?

What does the kernel do every tick?
What does the kernel do between two ticks?
What is the benefit of time interpolation?
Tick is the timer interrupt?
Jiffies are the number of ticks?

regards,
Kirilla

Kirilla · 02-27-2009, 08:04 AM

Hi,

I think I found the answer some of my questions.

What does the kernel do every tick?
Check the runque and decide which process will get the CPU.

What does the kernel do between two ticks?
Runs the "current" process. I don't know why, but this simple thing was not clear for me. "The amount of time between the timer interrupt is
called a timeslice."

What is the benefit of time interpolation?
It is a question in the future too.

Tick is the timer interrupt?
yes

Jiffies are the number of ticks?
yes

regards,
Kirilla