Merge "Revert "mm: always flush VMA ranges affected by zap_page_range""

	tlb_gather_mmu(&tlb, mm, start, end);

	update_hiwater_rss(mm);

	mmu_notifier_invalidate_range_start(mm, start, end);

	for ( ; vma && vma->vm_start < end; vma = vma->vm_next) {

	for ( ; vma && vma->vm_start < end; vma = vma->vm_next)

		unmap_single_vma(&tlb, vma, start, end, NULL);

		/*

		 * zap_page_range does not specify whether mmap_sem should be

		 * held for read or write. That allows parallel zap_page_range

		 * operations to unmap a PTE and defer a flush meaning that

		 * this call observes pte_none and fails to flush the TLB.

		 * Rather than adding a complex API, ensure that no stale

		 * TLB entries exist when this call returns.

		 */

		flush_tlb_range(vma, start, end);

	}

	mmu_notifier_invalidate_range_end(mm, start, end);

	tlb_finish_mmu(&tlb, start, end);

}