5 ms·

I wonder this as well. Might a kernel update not break some applications or make the system less stable?

eat_veggies 9y ago
It's probably safe since rolling release distributions upgrade just the kernel and work fine. I'd watch out for the graphics drivers though--sometimes you need to recompile them with the new kernel headers or just use the DKMS version.
Avshalom 9y ago
Linus is pretty big on kernel updates not breaking userland it's been the topic of several flames. Not that that's perfect or a guarantee but it is a priority among the devs.
- jug 9y ago
  Yes, he hates that with a vengeance, here's the classic thread. https://lkml.org/lkml/2012/12/23/75 https://lkml.org/lkml/2012/12/23/75
  - dotancohen 9y ago
    That's actually a bit recent to be "classic" but it is a great example.
mamon 9y ago
I've bought new laptop recently with Kaby Lake processor and put Ubuntu 17.04 on it, so the kernel upgrade was kind of necessity. No adverse effects observed, and on the plus side: somewhat better battery life, Asus USB-C docking station working correctly, including Gigabit Ethernet port, resolved issues with sleep/resume.
- johnbellone 9y ago
  What laptop if you don't mind me asking?
  - mamon 9y ago
    Dell XPS 13 (9360). I know, they sell those with Ubuntu pre-installed, but they are hard to come by in my country, so i bought Win10 version and installed Linux myself
dom0 9y ago
Linus Torvalds breaks into a childish tantrum of (edit: correction: swearing rants are technically coherent), public swearing at people whenever anyone anywhere in Linux kernel development breaks any userspace app. As a consequence, userspace regressions are rare. (Might contain traces of hyperbole—still; Linus' behaviour is largely unacceptable nonetheless)
- wtallis 9y ago
  Linus is very well known for his rants, but you've definitely mischaracterized them. He's seldom incoherent, and the ones that are vulgar enough to make for juicy sensationalized "news" are only ever directed at contributors who are experienced enough to know better than to break userspace or something badly wrong like that. His more level-headed corrections of well-meaning inexperienced developers don't make the news.
  - dom0 9y ago
    "only ever directed at contributors who are experienced enough". That's not strictly true, see e.g. https://lists.freedesktop.org/archives/dri-devel/2017-February/133837.html https://lists.freedesktop.org/archives/dri-devel/2017-Februa...
    - saghm 9y ago
      Props to Daniel for defending the contributor, as I'm guessing they wouldn't feel comfortable arguing back with Linus.
      - icebraining 9y ago
        To me it reads like redirecting blame to the contributor by appearing to "defend" him. Linus was obviously replying (and chastising) the person who sent him the code, and who was supposed to review it beforehand, not the original author.
        dullgiulio 9y ago
shp0ngle 9y ago
It might make some hardware unusable. If you are relying on some hacks or proprietary drivers for wifi support or GPU support (as is normal in Linux world), it might break.
cmurf 9y ago
It can happen. There are a bunch of bots that do regression tests, Fedora's Rawhide provides daily debug builds of the kernel with merges in-between the rc's, so there are are some real humans also using the kernel through its development. If you check the 4.11.1 changelog as an example you can see the kinds of things that can crop up. Fedora current releases tend to rebase around x.y.2. So you could use that as a way to weigh your kernel conservatism.
TeMPOraL 9y ago
So maybe a stupid question for me - but since all the answers here say that new kernels generally don't break userland, then... what do I get from an update? Security fixes? Faster syscalls? Because otherwise I can't think of changes that would affect me in any way without updating rest of the userland.
- Santosh83 9y ago
  Major distros backport security fixes. I'd say improved hardware support is 90% the reason to upgrade to a new kernel. Algorithmic improvements (like bfq) and new syscalls/subsystems are infrequent and one might not be able to make use of them immediately unless libs/userland adapt quickly.
agnivade 9y ago
I have been consistently updating linux kernels on by ubuntu machines. Apart from docker images going awry. I haven't experienced any other issue.

It's probably safe since rolling release distributions upgrade just the kernel and work fine. I'd watch out for the graphics drivers though--sometimes you need to recompile them with the new kernel headers or just use the DKMS version.

Avshalom 9y ago

Linus is pretty big on kernel updates not breaking userland it's been the topic of several flames. Not that that's perfect or a guarantee but it is a priority among the devs.

jug 9y ago
Yes, he hates that with a vengeance, here's the classic thread. https://lkml.org/lkml/2012/12/23/75 https://lkml.org/lkml/2012/12/23/75
- dotancohen 9y ago
  That's actually a bit recent to be "classic" but it is a great example.

mamon 9y ago

I've bought new laptop recently with Kaby Lake processor and put Ubuntu 17.04 on it, so the kernel upgrade was kind of necessity. No adverse effects observed, and on the plus side: somewhat better battery life, Asus USB-C docking station working correctly, including Gigabit Ethernet port, resolved issues with sleep/resume.

johnbellone 9y ago
What laptop if you don't mind me asking?
- mamon 9y ago
  Dell XPS 13 (9360). I know, they sell those with Ubuntu pre-installed, but they are hard to come by in my country, so i bought Win10 version and installed Linux myself

dom0 9y ago

Linus Torvalds breaks into a childish tantrum of (edit: correction: swearing rants are technically coherent), public swearing at people whenever anyone anywhere in Linux kernel development breaks any userspace app. As a consequence, userspace regressions are rare. (Might contain traces of hyperbole—still; Linus' behaviour is largely unacceptable nonetheless)

wtallis 9y ago
Linus is very well known for his rants, but you've definitely mischaracterized them. He's seldom incoherent, and the ones that are vulgar enough to make for juicy sensationalized "news" are only ever directed at contributors who are experienced enough to know better than to break userspace or something badly wrong like that. His more level-headed corrections of well-meaning inexperienced developers don't make the news.
- dom0 9y ago
  "only ever directed at contributors who are experienced enough". That's not strictly true, see e.g. https://lists.freedesktop.org/archives/dri-devel/2017-February/133837.html https://lists.freedesktop.org/archives/dri-devel/2017-Februa...
  - saghm 9y ago
    Props to Daniel for defending the contributor, as I'm guessing they wouldn't feel comfortable arguing back with Linus.
    - icebraining 9y ago
      To me it reads like redirecting blame to the contributor by appearing to "defend" him. Linus was obviously replying (and chastising) the person who sent him the code, and who was supposed to review it beforehand, not the original author.
      - dullgiulio 9y ago

shp0ngle 9y ago

It might make some hardware unusable. If you are relying on some hacks or proprietary drivers for wifi support or GPU support (as is normal in Linux world), it might break.

cmurf 9y ago

It can happen. There are a bunch of bots that do regression tests, Fedora's Rawhide provides daily debug builds of the kernel with merges in-between the rc's, so there are are some real humans also using the kernel through its development. If you check the 4.11.1 changelog as an example you can see the kinds of things that can crop up. Fedora current releases tend to rebase around x.y.2. So you could use that as a way to weigh your kernel conservatism.

TeMPOraL 9y ago

So maybe a stupid question for me - but since all the answers here say that new kernels generally don't break userland, then... what do I get from an update? Security fixes? Faster syscalls? Because otherwise I can't think of changes that would affect me in any way without updating rest of the userland.

Santosh83 9y ago
Major distros backport security fixes. I'd say improved hardware support is 90% the reason to upgrade to a new kernel. Algorithmic improvements (like bfq) and new syscalls/subsystems are infrequent and one might not be able to make use of them immediately unless libs/userland adapt quickly.

agnivade 9y ago

I have been consistently updating linux kernels on by ubuntu machines. Apart from docker images going awry. I haven't experienced any other issue.