On Oct 30, 2022, at 11:43 AM, Peter Xu peterx@redhat.com wrote:
The loop comes from 7e027b14d53e ("vm: simplify unmap_vmas() calling convention", 2012-05-06), where zap_page_range() was used to replace a call to unmap_vmas() because the patch wanted to eliminate the zap details pointer for unmap_vmas(), which makes sense.
I didn't check the old code, but from what I can tell (and also as Mike pointed out) I don't think zap_page_range() in the lastest code base is ever used on multi-vma at all. Otherwise the mmu notifier is already broken - see mmu_notifier_range_init() where the vma pointer is also part of the notification.
Perhaps we should just remove the loop?
There is already zap_page_range_single() that does exactly that. Just need to export it.