Re: [PATCH v2 1/4] x86/mm: no-one passes a NULL domain to init_xen_l4_slots()

[Jan Beulich <jbeulich@suse.com>]

On 07.05.2020 19:26, Andrew Cooper wrote:
> On 05/05/2020 07:31, Jan Beulich wrote:
>> On 21.04.2020 18:40, Roger Pau Monné wrote:
>>> On Tue, Apr 21, 2020 at 11:11:03AM +0200, Jan Beulich wrote:
>>>> Drop the NULL checks - they've been introduced by commit 8d7b633ada
>>>> ("x86/mm: Consolidate all Xen L4 slot writing into
>>>> init_xen_l4_slots()") for no apparent reason.
>>>>
>>>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>>> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
>> you weren't entirely happy with the change because of the
>> possible (or, as you state, necessary) need to undo this. I
>> still think in the current shape the NULL checks are
>> pointless and hence would better go away. Re-introducing them
>> (adjusted to whatever shape the function may be in by that
>> time) is not that big of a problem. May I ask that you
>> explicitly clarify whether you actively NAK the patch, accept
>> it going in with Roger's R-b, or would be willing to ack it?
> 
> I'm not going to nack it, because that would be petty, but I still don't
> think it is a useful use of your time to be making more work for someone
> in the future to revert.
> 
> However, if you wish to take the patch with Roger's R-b, then please fix
> the stale commit message, seeing as this is v2 and I explained exactly
> why it was done like that.

Is "... without giving a reason; I'm told this was done in anticipation
of the function potentially getting called with a NULL argument" any
better? I don't think the commit message here was stale, as said commit
indeed gives no explanation, yet all call sites pass non-NULL.

Jan