Hi,
The average load on my idling iMac is above 1.00 but it definitely should be close to 0.00. Since the CPU usage is low I suspect that Sierra includes processes using Disk I/O in the load calculation but I cannot identify the process responsible for the activity. I am running 10.12.6. Here is output from uptime:
$ uptime
0:47 up 14:56, 2 users, load averages: 1.31 1.57 1.48
iMac with Retina 5K display
This is what I get If I run top -o +state
There are two processes in the running state: top and kernel_task. It is difficult to say for sure if kernel_task is in the running state if I don't run top but since the average load is above 1.00 all the time I assume it is. Now the question is why kernel_task is not sleeping. Kernels are just event handlers and should never be in running state. Why does it matter. On a machine that has four or more CPU cores you would most likely not notice any difference, especially on a lightly used one. But on a machine with just two cores, like my old Mac mini I can notice that since I upgraded to 10.12.6 it got slower. I guess this is because one core is always assigned by the scheduler to handle this parasitic task and the other core is free to be assigned to handle other events that show up on process queue in the kernel. BTW on my very old MacBook running Lion the average load is close to zero.
Well, there are no 'jobs' in macOS. This is just a catch-all layman term. To be precise scheduling in macOS is done on a level of threads as can be seen here https://developer.apple.com/library/content/documentation/Darwin/Conceptual/Kern elProgramming/Mach/Mach.html
When I was talking about processes I was thinking about them in general sense, as a unit of execution.
A queue is a dynamic data structure that implements FIFO. Its length represents number of entries i.e. if it contains two elements its length is 2. On an idling system the only events needed attention from the OS are internally generated. Handling such events should be very efficient thus they should never rise the load level to 1.00. If the load is 1.00 on an idling system you can think that one CPU core is dedicated just to maintain the system which is obviously wrong.
j.kroliko wrote:
The average load on my idling iMac is above 1.00 but it definitely should be close to 0.00.
No, it shouldn't. Why would you believe that to be the case?
BTW on my very old MacBook running Lion the average load is close to zero.
The reason is that Lion required a lot fewer concurrent jobs than Sierra.
There is nothing wrong with your Mac. If you suspect something is, explain.
As I explained the average load is the measure of the length of process queue in the scheduler and a value of 1.00 means that on average it contains at least one 'ready' process entry. The larger number of concurrent threads/processes in Sierra should not matter as on the idling system they all should be sleeping/waiting on events. I am not sure about the macOS load accounting but if disk I/O is contributing to the load as it is in Linux, such process fits the situation here as disk I/O is mostly handled by DMA system and show almost zero CPU usage. Do I suspect something? I have too little knowledge about macOS. This is why I have asked this question here. But I don't believe it is normal.
You have been misinformed. From the manpages "the load average numbers give the number of jobs in the run queue averaged over 1, 5 and 15 minutes."
1 or close to it is completely normal for a system in an idle state.
Hello j.kroliko,
Your numbers are normal. While macOS looks and acts a lot like other UNIX/Linux systems, it is completely different. I poked around on the Apple open source site until I lost interest. If you want more information, go look of the kernel global "averunnable". It seems to keep that value up to date. All of the load queries just return the value in averunnable.
The CPU load is low as expected. The only unusual thing is the disk:
What does Activity Monitor tell you?
I have these values:
10:53 up 17 days, 3:53, 4 users, load averages: 1,86 1,93 1,94
And my Mac is running well 🙂
If I look at Activity Monitor or top i never have less than one process active. Usually several.
The kernel_task is not the kernel. It seems that it is doing much more than merely handling events. memory - What exactly does kernel_task do? - Ask Different
Handling such events should be very efficient thus they should never rise the load level to 1.00.
Well, they do. How do you propose to fix it?
Yes, let's leave it at that. Thank you all for participating in this discussion.
Why average load on my idling iMac is above 1.00?
