[Bug 1728760] [NEW] 17.04 to 17.10 dist upgrade automatically switched me to lowlatency kernel

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When I upgraded from 17.04 to 17.10, I was automatically switched from
the generic kernel to the lowlatency kernel. I did not have the
lowlatency kernel installed prior to the dist upgrade (I have verified
this by inspecting my /var/log/apt/history.log* files, all upgrades
prior to the dist upgrade only show updating *-generic kernel packages,
if I had lowlatency installed it would show that as well.) I'm not sure
why I was switched to lowlatency, I don't see anything in the release
notes saying that there was a switch to lowlatency as the default, and
other users who have just done a dist upgrade weren't switched to
lowlatency. So I think it is probably a bug that I was switched to
lowlatency - perhaps there's a package that I have installed that is
incorrectly depending on the lowlatency kernel in 17.10? I'm not sure
how to find out if that's the case.

To be explicit, after the dist-upgrade, I had both the 4.13.0-16-generic
and 4.13.0-16-lowlatency kernels installed, and by default
4.13.0-16-lowlatency was what was booted into.

This also caused a problem when I did the upgrade - perhaps this is a
separate bug that I should report, let me know and I'll do that. After
the dist-upgrade, wifi didn't work. I have a BCM4352 wifi card, whose
driver is provided by the bcmwl-kernel-source package, which uses DKMS
to compile it. Presumably during the dist-upgrade, the driver was
compiled for the 4.13.0-16-generic kernel, so when I manually selected
that kernel on boot, it worked, but it wasn't compiled for the
4.13.0-16-lowlatency kernel, which is why wifi didn't work out of the
box after the dist-upgrade. The solution was of course straight forward,
I had to reinstall the bcmwl-kernel-source package, but a non working
system after an upgrade requiring reinstalling packages or booting into
a different kernel to fix is presumably a bug.

If the switch from generic to lowlatency was a feature, not a bug, then
such a switch should also be accompanied by compiling all the kernel
modules that were compiled against the generic kernel against the new
lowlatency kernel, so as to ensure the system is in a working state
after completing a dist upgrade. Also, if the switch is a feature, then
I would expect it to be documented in the release notes with a brief
explanation or link to more information on why the switch was done.

** Affects: ubuntu-release-upgrader (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: bot-comment
-- 
17.04 to 17.10 dist upgrade automatically switched me to lowlatency kernel
https://bugs.launchpad.net/bugs/1728760
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