Mac cpu time spontaneously exceeds local computing preferences

[chilina]

Describe the bug

There is a forum thread here on the Einstein project: https://einsteinathome.org/content/m1-mac-cpus-max-out-their-own-overnight#comment-238988

Basically, twice (total) now on two different Mac minis (M1 and M4), I've had the cpu time jump on its own from 30% to 100%. The computing preferences tab retains my settings (of 30%). I confirmed that cpu usage was purely from Boinc projects in the macOS Activity Monitor. A reboot of macOS will fix the problem.

I only run Einstein projects, and only their FGRP5 project, which is cpu-only. I always run my computers from local preferences. Both minis had local preferences set to 30% cpus and 30% cpu time, for both "in use" and "while not in use" options.

Steps to reproduce

No response

Expected behavior

No response

Screenshots

No response

System information

No response

Additional context

No response

[chilina]

Also, both mins are running macOS 15.6.1 and Boinc 8.2.5. One may have been running 15.6.0 during the first instance of the issue (the M1).

[AenBleidd]

@CharlieFenton, please take a look if this is valid.

[CharlieFenton]

@AenBleidd This would be in the client, so @davidpanderson is the person to look into it.

[davidpanderson]

How many jobs is BOINC running? Is it 30% of the # of CPUS?

[chilina]

Hey yes davidpanderson typically 3 jobs per mini. A 30% setting for CPUS in local preferences would be 3 jobs on the M4 (10 cores total), and 38% would be 3 jobs on the M1 (8 total). Both machines have 4 performance cores, and the jobs only seem to run on those.

[AenBleidd]

@chilina,

Both machines have 4 performance cores, and the jobs only seem to run on those.

BOINC client doesn't assign any WU to a particular core, this is done by the OS.

[chilina]

I could upgrade to Tahoe and see if this happens again. Sometimes upgrading can be helpful in resolving certain weird Mac behaviors. I searched for open Issues for "Mac cpus" and didn't see anything. And I see that there are log files in the Boinc folder so happy to send those along if they would be helpful.

This feels like a difficult problem because it's very intermittent, and I don't think there is anything I can do to trigger or reproduce it. Both of the occurrences have happened when the Macs were not being used for anything but Boinc.

I'm a long-time Boinc user, with linux and windows desktops before the Macs, and even going back to the Seti project in the late 1990s before Boinc. I don't recall ever having any issues in all of that time.