QEMU/KVM CPU usage only shown in process list, not in overall CPU usage

[ThomasFrans]

Checklist

• I've looked through troubleshooting, known problems, and existing open issues for similar issues.

What operating system and version are you using?

Arch Linux 6.5.7

What architecture are you using?

x86_64 / AMD64

What terminal(s) are you running bottom on?

Alacritty 0.12.3

Are you using ZFS?

No

What version of bottom are you running?

0.9.6

How did you install bottom?

Installed from the official Arch extra repository.

Describe the issue

bottom doesn't show CPU usage in the general CPU widget while it does show it in the process list. I don't know what exactly causes this but I noticed it while using a QEMU/KVM virtual machine running FreeBSD. If I compile a Rust crate in the VM while having bottom open on the host, the process list will show the QEMU process using 100% of the CPU, but it isn't reflected in the CPU widget at all. The CPU widget will sit at 6% or lower. See the screenshot below where virt-manager is definitely showing the CPU usage, and the bottom process list shows it as well, but it isn't visible in the CPU widget.

What is the expected behaviour?

I expect the general CPU widget to always show a 'summary' of the process list's CPU usage.

What is the actual behaviour?

The combined CPU usage of the process list doesn't equal the one shown in the CPU widget.

How can we reproduce this?

1. Install a VM in QEMU/KVM (I used FreeBSD here, but it works with any OS)
2. Do some heavy computation in the VM
3. Watch bottom on the host machine

Additional information

No response

[ClementTsang]

Will take a look at this - VMs sometimes cause some weird issues, yeah.