Re: [PATCH 3/3] static_call: Fix static_call_update() sanity check

[Jessica Yu]

+++ Steven Rostedt [19/03/21 14:00 -0400]:
> On Fri, 19 Mar 2021 13:57:38 +0100
> Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> > Jessica, can you explain how !MODULE_UNLOAD is supposed to work?
> > Alternatives, jump_labels and static_call all can have relocations into
> > __exit code. Not loading it at all would be BAD.
>
> According to the description:
>
> " Without this option you will not be able to unload any
>  modules (note that some modules may not be unloadable anyway), which
>  makes your kernel smaller, faster and simpler.
>  If unsure, say Y."
>
> Seems there's no reason to load the "exit" portion, as that's what makes it
> "smaller".

Exactly. If you disable MODULE_UNLOAD, then you don't intend to ever
unload any modules, and so you'll never end up calling the module's
cleanup/exit function. That code would basically be never used, so
that's why it's not loaded in the first place.