nrfutil uses a large amount of CPU time when run under Linux.

[Burt]

I have found that in Linux, "nrfutil toolchain-manager launch --shell" is starting a process that uses almost 20% of the CPU according to the top utility. I have found this directly on a Ubuntu machine and also with Windows Subsystem for Linux. I may be running 24.04-1 but I am guessing it will be the same for 22.04-1.

I don't know why it should use any resources if it just exports environment variables. In fact, I tried to tease out most of the environment variables added/modified by nrfutil...--shell and run a simple script that exports the same variables into a basic bash shell.  This seems to allow me to build and I don't see anything gobbling up CPU. But I'd rather run nrfutil...--shell rather than my hack script--minus wasting CPU.

Burt

[Charlie]

HI Burt,

You can try to export the toolchain env to your current shell by running this command `source <(nrfutil toolchain-manager env --as-script --ncs-version v2.7.0)`.

This will hopefully save some CPU power if you really concern. I will feedback to developer to see if there are some optimization can be done.

Best regards,

Charlie

[Burt]

Thanks, Charlie. Very nice. I was at first thrown off by the back quotes, but then realized they are just delimiters for the command. And it would be nice for me to have some basic understanding of why the usual "launch --shell" uses so much power, so I appreciate any information (or actions) from the developer.

Burt

[Charlie]

Hi Burt,

I asked my colleague to have a try on ubuntu 22.04 and do not see the increased cpu usage. I will try to get one with ubuntu 2.4.04 to do test.

At the same time, could you proivde more informaiton about your PC(like processer) and system? 

Best regards,

Charlie

[Burt]

Hi Charlie,

I tried it using WSL: I added a WSL Ubuntu-22.04.5 machine to my Windows machine (I had already tested with the default 24.04.1 and on a regular Linux machine (non VM) as I originally stated). I decided to install the latest toolchain: 2.8.0 as long as it now exists. I get the same exact behavior as previously. Running the "top" command, the first process listed is nrfutil. I probably can only set up a different type of virtual machine (like VirtualBox) to illustrate another 22.04 instance, but the WSL seems to mirror a physical machine. Yeah, too much work to go beyond what I have already done!

Burt

(v2.8.0) burt@T450S:~$ top
top - 10:05:05 up 18 min, 2 users, load average: 0.02, 0.15, 0.09
Tasks: 30 total, 1 running, 29 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.5 us, 1.6 sy, 0.0 ni, 97.8 id, 0.1 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 5866.8 total, 116.3 free, 455.9 used, 5294.6 buff/cache
MiB Swap: 2048.0 total, 2048.0 free, 0.0 used. 5121.8 avail Mem

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
796 burt 20 0 24992 10112 8628 S 18.9 0.2 0:02.11 nrfutil

1 root 20 0 165772 10892 8076 S 0.0 0.2 0:01.15 systemd
2 root 20 0 2460 1340 1224 S 0.0 0.0 0:00.00 init-sy+
6 root 20 0 2476 196 196 S 0.0 0.0 0:00.01 init
62 root 19 -1 47736 14548 13516 S 0.0 0.2 0:00.54 systemd+
85 root 20 0 21704 5580 4388 S 0.0 0.1 0:00.74 systemd+
105 systemd+ 20 0 25664 12436 8080 S 0.0 0.2 0:00.20 systemd+
119 systemd+ 20 0 89364 6548 5744 S 0.0 0.1 0:00.20 systemd+
167 root 20 0 4308 2752 2516 S 0.0 0.0 0:00.01 cron
168 message+ 20 0 8588 4552 4008 S 0.0 0.1 0:00.22 dbus-da+
173 root 20 0 30044 18132 9328 S 0.0 0.3 0:00.20 network+
174 syslog 20 0 222404 7056 4256 S 0.0 0.1 0:00.06 rsyslogd
177 root 20 0 15332 7584 6600 S 0.0 0.1 0:00.23 systemd+
213 root 20 0 107128 20232 12052 S 0.0 0.3 0:00.16 unatten+
284 root 20 0 7528 4892 3972 S 0.0 0.1 0:00.01 login
337 burt 20 0 16964 9200 7704 S 0.0 0.2 0:00.17 systemd
338 burt 20 0 103288 3308 12 S 0.0 0.1 0:00.00 (sd-pam)

[Charlie]

Hi Burt,

Thank you for sharing your observations. I can confirm that this behavior is repeatable on Ubuntu systems, including versions 22.04, 24.04, and WSL Ubuntu.

I have reported this potential improvement to our nrfutil developers, and an enhancement will hopefully come in the near future update. I will keep you informed of any progress.

Best regards,

Charlie