On 2017-11-06 22:37, Rémi Denis-Courmont wrote:
> In my opinon, tis is still utterly pointless. Really, what bug did this
> specific patch help to fix?
I'm maintainer of legacy OpenVz kernels, we release containers-ready kernels
15+ years,
they are widely used by hosting providers, usually they use 30-300 containers
per node.
In this scenario if any of container causes the problem it affects many other.
For many years we got lot of strange memory corruptions and found lot of memory
leaks
in namespace-fied subsytems.
These bugs are invisible on usual kernls, because init_net lives forever and
never destroyed.
However they are quite important for systems running lott of independent
namespaces,
that can be restarted many times without host admin assistance.
Each memory leak can be repeated many times and finally it enables OOM-killer
that disables whole node. And nobody understand what's happen.
Such kind of checks allows to be sure that net namespace exit was clear and
leaked nothing.
> If you want to debug network namespaces, I have a feeling that the network
> namespace code is a better place to do so than individual protocol stacks.
Common network namespace code knows nothing about specific of each individual
driver/subsystem.
I do not understand how it's possible to do it in common netns code.
Thank you,
Vasily Averin
