On 11/7/19 3:36 PM, Jason Gunthorpe wrote:
> On Tue, Nov 05, 2019 at 10:16:46AM -0500, Boris Ostrovsky wrote:
>
>>> So, I suppose it can be relaxed to a null test and a WARN_ON that it
>>> hasn't changed?
>> You mean
>>
>> if (use_ptemod) {
>> WARN_ON(map->vma != vma);
>> ...
>>
>>
>> Yes, that sounds good.
> I amended my copy of the patch with the above, has this rework shown
> signs of working?
Yes, it works fine.
But please don't forget notifier ops initialization.
With those two changes,
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
>
> @@ -436,7 +436,8 @@ static void gntdev_vma_close(struct vm_area_struct *vma)
> struct gntdev_priv *priv = file->private_data;
>
> pr_debug("gntdev_vma_close %p\n", vma);
> - if (use_ptemod && map->vma == vma) {
> + if (use_ptemod) {
> + WARN_ON(map->vma != vma);
> mmu_range_notifier_remove(&map->notifier);
> map->vma = NULL;
> }
>
> Jason
