On Fri, Feb 12, 2021 at 01:34:03PM -0800, Mike Kravetz wrote:

I'm good with the new MMU_NOTIFY_HUGETLB_UNSHARE and agree with your reasoning
for adding it.  I really did not know enough about usage which caused me to
question.

It actually is a good question..  Because after a 2nd thought I cannot think of
any mmu notifier usage to explicitly listen to huge pmd unshare event - it
could be just a too internal impl detail of hugetlbfs.  I think any new flag
should justify itself when introduced.  Before I could justify it, I think
MMU_NOTIFIER_CLEAR is indeed more suitable.

Thanks,

-- 
Peter Xu