[kpatch] Deprecation of 'kpatch replace'

[Evgenii Shatokhin]

03.11.2015 21:14, Josh Poimboeuf пишет:
> On Tue, Nov 03, 2015 at 07:06:42PM +0300, Evgenii Shatokhin wrote:
>> 03.11.2015 18:07, Josh Poimboeuf пишет:
>>> On Tue, Nov 03, 2015 at 12:14:06PM +0300, Evgenii Shatokhin wrote:
>>>> Hi,
>>>>
>>>> As far as I can see in the commit message for
>>>> 353f976312bbf24b27d29d21b1b2f8ce75ded3e4 "test: integration test cleanup",
>>>> "kpatch replace" is deprecated.
>>>>
>>>> If so, what is the recommended way to replace the currently loaded patch
>>>> modules with a new one? 'kpatch unload --all' followed by 'kpatch load' or
>>>> something more tricky?
>>>
>>> Hi Evgenii,
>>>
>>> The recommended upgrade approach is for the new patch to be a superset
>>> of the old one.  Then you just "kpatch load" the new patch.  The old
>>> patch can remain loaded, but all of its functions are replaced by the
>>> new patch.
>>
>> Interesting. So, is it OK to load a new patch (which is the superset of the
>> old one) first and then unload the old one?
>
> IIRC, kpatch allows it.  (Note: be careful if the patch has load/unload
> hooks.)
>
> However, upstream livepatch doesn't allow it because it assumes there
> may be dependencies between the modules.  It enforces strict stacking
> semantics.  But we've had some discussions about changing that behavior.
>

I see. Thanks for the explanation.

Regards,
Evgenii