Islandscout
Posts: 9
Joined: Tue Nov 07, 2017 5:23 am

Weird CPU core management

Thu Apr 19, 2018 4:56 am

I just want to start off by saying that I'm not an advanced Linux user. I've started using Linux distros since almost a year ago and I feel pretty confident about understanding the basic structure of Linux. I've found Solus to be a great alternative to Windows when it comes to productivity. It's simple, solid, and lightweight compared to other popular modern PC operating systems.

One thing that I've discovered about the installation on this machine is that Solus tends to favor only one of my CPU cores. On some boots, it evenly distributes the load across all four cores, but on other boots, it seems to cram most of the load onto one core. In some cases, it will randomly switch to favor another core. The system feels sluggish and slow when this happens. I've never had this issue before on Windows. I don't know what's causing this or how to fix this permanently. I can temporarily fix it by suspending the system, and then spinning it back up.

I updated my system about a few hours ago.

Here are a couple of images illustrating what I mean.

htop:
Screenshot from 2018-04-18 17-16-23.png
Screenshot from 2018-04-18 17-16-23.png (31.42 KiB) Viewed 312 times
System Monitor:
Screenshot from 2018-04-18 20-25-20.png
Screenshot from 2018-04-18 20-25-20.png (17.18 KiB) Viewed 312 times
There doesn't seem to be anything unusual under processes.

System specs:
Toshiba Satellite c875-s7132nr
CPU: Intel Core i3-3120M @ 2.5GHz
RAM: 6GB DDR3
HDD: 640GB

sunnyflunk
Development Team
Posts: 2945
Joined: Sun Mar 13, 2016 11:35 pm

Re: Weird CPU core management

Fri Apr 20, 2018 4:54 am

If your load is single threaded, you would expect it to be on one CPU.

The usual process would be identifying what's causing the load and try to improve that.

Islandscout
Posts: 9
Joined: Tue Nov 07, 2017 5:23 am

Re: Weird CPU core management

Tue Apr 24, 2018 11:23 pm

There doesn't seem to be anything unusual under processes. This happens even when the system is idle. It's a half and half chance that when I start my machine this happens. It can be temporarily fixed if I suspend the system and wake it up again. (Even this takes a couple of tries)

One thing that surprises me is that my Dell laptop doesn't seem to experience this issue.

I have four more images to display, but they don't seem to be uploading properly. (Too large dimensions?) What a bummer, because I want to show the difference between idling and watching youtube under both normal and abnormal conditions.

Islandscout
Posts: 9
Joined: Tue Nov 07, 2017 5:23 am

Re: Weird CPU core management

Fri Jun 29, 2018 9:24 pm

Bump.
This is getting ridiculous. I had to suspend/wake the system seven times to get it to work properly. Can anyone explain this (even if it's the kernel that's causing it)? Again, nothing unusual appears under processes; no high CPU usage. It's just that the system tends to want to shove most of the load onto one core. I've never observed this in Windows.

sunnyflunk
Development Team
Posts: 2945
Joined: Sun Mar 13, 2016 11:35 pm

Re: Weird CPU core management

Mon Jul 02, 2018 10:25 am

Islandscout wrote:
Fri Jun 29, 2018 9:24 pm
Bump.
This is getting ridiculous. I had to suspend/wake the system seven times to get it to work properly. Can anyone explain this (even if it's the kernel that's causing it)? Again, nothing unusual appears under processes; no high CPU usage. It's just that the system tends to want to shove most of the load onto one core. I've never observed this in Windows.
Without seeing the processes, it's all guesswork. It's not abnormal for a task to 100% one CPU with no load on the others. An app that isn't threaded, can only run on one core.

Linux and windows tends to report CPU usage differently (depending on desktop). If you have 4 cores, the system monitor can up to 400% whereas that would only be 100% elsewhere. So 25% on a process could mean a CPU pegged at 100%.

Islandscout
Posts: 9
Joined: Tue Nov 07, 2017 5:23 am

Re: Weird CPU core management

Thu Jul 12, 2018 5:19 am

Well... here are a couple of screenshots of htop in both situations. I don't know what single-threaded program hogs up CPU like that, especially right when I boot up Solus.

Abnormal:
abnormal.jpg
abnormal.jpg (236.58 KiB) Viewed 43 times
Normal:
normal.jpg
normal.jpg (230.42 KiB) Viewed 43 times
I read a thread on Serverfault that was very similar to my issue. https://serverfault.com/questions/44608 ... tilization The OP of the thread ran a command to diagnose the issue (cat proc/interrupts) and I ran it, too. I have no clue what the numbers mean, though.
proc interrupts.jpg
proc interrupts.jpg (69.85 KiB) Viewed 43 times

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