Correctly show /sys/devices/system/cpu/cpu*/online, currently all threads are always shown online

[C0rn3j]

#88 partially solved the online issues by showing correct overall view in /sys/devices/system/cpu/online

However online marker in /sys/devices/system/cpu/cpu*/online is always set to 1, i.e. online.

# cpu.limit = 6, but all 48 threads are set to online in the distinct files
cat /sys/devices/system/cpu/online /sys/devices/system/cpu/cpu*/online
2,5,19,21,24,30
1
1
1
1
1
1
1
1
1
1
1
1
…

This is on LXD 5.19 with 5.15.0-58-generic kernel.

[mihalicyn]

Hi @C0rn3j!

Your suggestion is to show all CPUs except 2,5,19,21,24,30 (in your example case) like offlined ones, right?

WDYT @stgraber?

[mihalicyn]

It can also be very very useful if you provide a bit of extra context why this is important (for example, you have piece of (open-source) software X that does not work correctly because of that).

[C0rn3j]

Your suggestion is to show all CPUs except 2,5,19,21,24,30 (in your example case) like offlined ones, right?

Indeed!

It can also be very very useful if you provide a bit of extra context why this is important (for example, you have piece of (open-source) software X that does not work correctly because of that).

It breaks htop, as its fallback logic when online threads aren't actually online is wrong.

I've sent a PR for that actually, but I don't think it would have been necessary if the CPUs were reported as offline in the first place.

htop-dev/htop#1394

[stgraber]

@mihalicyn having the CPUs listed but having LXCFS fake them being offline should be fine.