New Linux CPU Hot-Plugging Works Out "Nightmare"

[phoronix]

Phoronix: New Linux CPU Hot-Plugging Works Out "Nightmare"

The current Linux kernel CPU hot-plugging support has been described as "an increasing nightmare full of races and undocumented behaviour", but fortunately it's in the process of being re-developed...

http://www.phoronix.com/vr.php?view=MTI4OTQ

[kaprikawn]

Forgive my ignorance, but what exactly is cpu hot-plugging? Is it, as the name implies, installing and removing a cpu while the machine is powered on? If so, I guess this is server-level stuff, I can't see me needing to (or indeed being able to) swap out the cpu on my desktop.

[pingufunkybeat]

Forgive my ignorance, but what exactly is cpu hot-plugging? Is it, as the name implies, installing and removing a cpu while the machine is powered on?

Correct.

If so, I guess this is server-level stuff, I can't see me needing to (or indeed being able to) swap out the cpu on my desktop.

Correct.

[Delgarde]

Forgive my ignorance, but what exactly is cpu hot-plugging? Is it, as the name implies, installing and removing a cpu while the machine is powered on? If so, I guess this is server-level stuff, I can't see me needing to (or indeed being able to) swap out the cpu on my desktop.

I guess this potentially also applies to VMs, not just physical machines - does assigning a couple of extra cores to a VM count as CPU hotplugging?

[dante]

I hope i'm wrong but i think Linux kernel developers are forgetting to maintain the quality of code, adding features to the system is important but the quality should come on top of priority.

[Drago]

I hope i'm wrong but i think Linux kernel developers are forgetting to maintain the quality of code, adding features to the system is important but the quality should come on top of priority.

What you don't like of the current patch-set?

[fackamato]

I hope i'm wrong but i think Linux kernel developers are forgetting to maintain the quality of code, adding features to the system is important but the quality should come on top of priority.

Uh. In short: you're wrong

[smitty3268]

I hope i'm wrong but i think Linux kernel developers are forgetting to maintain the quality of code, adding features to the system is important but the quality should come on top of priority.

Uh, isn't that exactly what this patch set is trying to do?

[boast]

I hope i'm wrong but i think Linux kernel developers are forgetting to maintain the quality of code, adding features to the system is important but the quality should come on top of priority.

So you are saying Thomas Gleixner should be forced to work on other parts of the linux kernel (which are not a part of his domain) to improve code quality? Or that they should reject his code and only accept code that improves quality on other parts of the kernel, and then accept his code after other parts are good enough?

[przemoli]

This may be usefull for ARM crowd, where turning off cores can be used for power saving. Assuing hotpluggin CPU's can be used for hotpluggin CPU's cores.