On Sat, 2020-09-26 at 11:45 -0400, Sam Varshavchik wrote:
Patrick O'Callaghan writes:
> There is a long-standing project that aims to do something like that (
>
https://github.com/dynup/kpatch), but AFAIK it's not production quality
> so far. Personally, I'm sceptical that it will ever be useful except in
> very constrained conditions. For one thing, it's not clear that there's
> much demand for it.
No, that's not what this is trying to do. Not even close.
This project attempts to implement the ability to patch the running kernel,
in a number of limited situations.
This is nowhere close to loading a brand new kernel and somehow seamlessly
switching to it.
For completeness, I'll mention that there are solutions that
semantically reboot into a brand new kernel but transfer the userspace
state to it with a minimum of actual downtime:
https://criu.org/Seamless_kernel_upgrade
This is like hibernating and immediately resuming except that the
userspace state is transferred in a format that is compatible across
kernel versions. However, it's unclear if any of these solutions are
reasonable for typical end users.
Matt