Re: [RFC PATCH v1.9 00/14] livepatch: hybrid consistency model

From: Petr Mladek
Date: Thu Apr 07 2016 - 08:10:38 EST


On Fri 2016-03-25 14:34:47, Josh Poimboeuf wrote:
> TODO:
> - try ftrace handler switching idea from v1 cover letter

I have had a discussion about it with Mirek. This would help with
kthreads. If they are sleeping in a patched function, we wake
them up, this will help to migrate them before they get asleep again.

But it might be quite tricky. We must make sure to avoid a deadlock.
We probably should not check the stack in atomic context or
in time sensitive functions.

An alternative would be to check the stack and try migration
when the process goes into a sleep. It is a location where
we should not be afraid of any deadlocks or slight delay.
There should be high changes for a successful migration with
a minimal impact on the system throughput.

Best Regards,
Petr