Hi i'm reading Linux Kernel Development 3rd edition and i'm at the chapter where it explains CFS. Generally i got it how it works but i have some questions about details ?
In the book on pages 48-49 it explains the algorithm how it works. In the book it says that :
"Each process runs for a timeslice proportional to its weight divided by the total weight of all runnable threads". The algorithm sets a targeted latency and it shares that process time among the processes according to their priorities. That is clear , but what is not clear is the example at the same paragraph :
He says if we have 2 processes and have 20ms to share between them each will run 10 ms "Regardless of their priority". Doesnt that explanation conflicts with one above ?
Also another example the author gives is not very clear again:
At the end of the page 49 he gives 2 examples :
The latency is 20ms , there are 2 processes 0 and 5 (nice valued) and each have 15 and 5 ms.
The second example is 2 processes at nice values 10 and 15 and they got again 15 and 5 ms.
Can someone explain me the math above , i couldnt explain myself how that process time is divided among those processes.
Thanks in advance ....
