Re: [RFC PATCH 1/4] mm: use current as mmu notifier's owner

["Mika Penttilä" <mpenttil@redhat.com>]

On 8/14/25 20:20, Jason Gunthorpe wrote:

> On Thu, Aug 14, 2025 at 08:00:01PM +0300, Mika Penttilä wrote:
>> as well as hmm test module with :
>>
>>          * Ignore invalidation callbacks for device private pages since
>>          * the invalidation is handled as part of the migration process.
>>          */
>>         if (range->event == MMU_NOTIFY_MIGRATE &&
>>             range->owner == dmirror->mdevice)
>>                 return true;
> If I recall this was about a very specific case where migration does a
> number of invalidations and some of the earlier ones are known to be
> redundant in this specific case. Redundant means it can be ignored
> without causing an inconsistency.
>
> Alistair would know, but I assumed this works OK because the above
> invalidation doesn't actually go on to free any pages but keeps them
> around until a later invalidation?
>
> This is nothing like what your case is talking about.

This one is actually pretty similar, MMU_NOTIFY_CLEAR is also fired in migration process
(split case) and invalidation handled part of the migration process.

But I have already a working version without any of that.

>
> Jason
>
--Mika