Re: [RFC] sched,livepatch: call klp_try_switch_task in __cond_resched

[Rik van Riel]

On Tue, 2022-05-10 at 17:44 +0200, Petr Mladek wrote:
> On Tue 2022-05-10 13:33:13, Rik van Riel wrote:
> > On Tue, 2022-05-10 at 09:56 +0200, Petr Mladek wrote:
> > 
> 
> > I think the best approach for us might be to just track what
> > is causing the transition failures, and send in trivial patches
> > to make the outer loop in such kernel threads do the same KLP
> > transition the idle task already does.
> 
> I am afraid that is a way to hell. We might end up in doing
> really crazy things if we want to complete the transition
> in one minute.
> 
Now I wonder if we could just hook up a preempt notifier
for kernel live patches. All the distro kernels already
need the preempt notifier for KVM, anyway...

Is it crazy? Maybe a little.

Is it self contained, and something that could be done
without inserting any extra code into a hot path while
not in the middle of a KLP transition? Yes.

I'd be happy to come up with a patch that does that,
unless anybody has good reasons I should not :)