Jason Gunthorpe <jgg@xxxxxxxxxx> writes: > On Mon, Jul 24, 2023 at 07:54:38AM +0000, Kasireddy, Vivek wrote: >> And replace mmu_notifier_update_mapping(vma->vm_mm, address, pte_pfn(*ptep)) >> in the current patch with >> mmu_notifier_change_pte(vma->vm_mm, address, ptep, false)); > > It isn't very useful because nothing can do anything meaningful under > the PTLs. Can't allocate memory for instance. Yeah, although you already have to be pretty careful allocating memory from a notifier while holding any lock as it may trigger direct reclaim which can call the same notifier leading to a recursive lock. A totally different discussion though. > JAson