Linux scheduler: Measuring the idleness of a CPU

mistic0423 · 08-04-2016, 08:13 PM

Hello,

I couldn't understand the explanation about idleness of a CPU in below PDF.

Quote:

%util of cpu1 < %util of cpu0
Thus cpu1 is less idle than cpu0

Why cpu1(utilization:30%) is LESS idle than cpu0(utilization:100%)?
The cpu1 seems to be MORE idle than cpu0. doesn't it?
(do I understand correctly the term 'Idle'?)

You can find the explanation on the page of
'Measuring the idleness of a CPU' in https://events.linuxfoundation.org/i...thy.pdf?update

Thanks,

dijetlo · 08-08-2016, 07:56 PM

Mistic I think the quy is referencing the idleness of the scheduler, suggesting that a CPU that runs a task consistently is idle from the schedulers perspective, however workloads processing through a second CPU represent workload for the scheduler.
At least I think that's what he's trying to convey, he's not clear in his power point

mistic0423 · 08-09-2016, 04:25 AM

Aha, your explanation seems to be right :-)
Thanks for your comments!