Linux KVM is meant for VM guests and probably therefore was set to CONFIG_BASE_SMALL=1.
The discussion "if this makes sense or not" is up to the kernel team but it seems this bug has got no attention by them yet :-/.
I was quickly assessing the case and found:
- Linux-generic is on CONFIG_BASE_SMALL=0 in B/F/G/H as one would expect.
- linux-kvm in B/F/G/H was all the time set to CONFIG_BASE_SMALL=0
- the option we talk about here is [1][2]
- IMHO "speed loss for saving a few KB" does not sound right. IIRC linux-kvm was meant more for
speed than density. We are virtual, but not as small as an embedded controller for example.
- This goes back to [3] when linux-kvm was introduced
- I didn't find a commit in [4] that listed any extended reasoning/discussion when enabling [5] it.
IMHO I agree and this should be switched in the kernel config.
I don't think that changing the pid-max was wrong. Even older Xenial linux-kvm running in 2020 can be considered bigger than what CONFIG_BASE_SMALL was meant for.
But further actions are for the kernel Team to consider and make. Therefore I'm adding a src:linux task, subscribing some more people and pinging the kernel team internally to get some attention.
Linux KVM is meant for VM guests and probably therefore was set to CONFIG_ BASE_SMALL= 1.
The discussion "if this makes sense or not" is up to the kernel team but it seems this bug has got no attention by them yet :-/.
I was quickly assessing the case and found: discussion when enabling [5] it.
- Linux-generic is on CONFIG_BASE_SMALL=0 in B/F/G/H as one would expect.
- linux-kvm in B/F/G/H was all the time set to CONFIG_BASE_SMALL=0
- the option we talk about here is [1][2]
- IMHO "speed loss for saving a few KB" does not sound right. IIRC linux-kvm was meant more for
speed than density. We are virtual, but not as small as an embedded controller for example.
- This goes back to [3] when linux-kvm was introduced
- I didn't find a commit in [4] that listed any extended reasoning/
IMHO I agree and this should be switched in the kernel config.
I don't think that changing the pid-max was wrong. Even older Xenial linux-kvm running in 2020 can be considered bigger than what CONFIG_BASE_SMALL was meant for.
But further actions are for the kernel Team to consider and make. Therefore I'm adding a src:linux task, subscribing some more people and pinging the kernel team internally to get some attention.
[1]: https:/ /mirrors. edge.kernel. org/pub/ linux/kernel/ people/ akpm/patches/ 2.6/2.6. 11-rc5/ 2.6.11- rc5-mm1/ broken- out/base- small-introduce -the-config_ base_small- flag.patch /github. com/torvalds/ linux/blob/ master/ init/Kconfig# L1518 /kernel. ubuntu. com/~kernel- ppa/config/ xenial/ linux-kvm/ 4.4.0-1004. 9/amd64- config. flavour. kvm /git.launchpad. net/~canonical- kernel/ ubuntu/ +source/ linux-kvm/ tree/debian. kvm/config/ config. common. ubuntu# n157 /git.launchpad. net/~canonical- kernel/ ubuntu/ +source/ linux-kvm
[2]: https:/
[3]: https:/
[5]: https:/
[4]: https:/