On Tue, May 09, 2023 at 09:39:13PM -0700, Hugh Dickins wrote: > Two: pte_offset_map() will need to do an rcu_read_lock(), with the > corresponding rcu_read_unlock() in pte_unmap(). But most architectures > never supported CONFIG_HIGHPTE, so some don't always call pte_unmap() > after pte_offset_map(), or have used userspace pte_offset_map() where > pte_offset_kernel() is more correct. No problem in the current tree, > but a problem once an rcu_read_unlock() will be needed to keep balance. Hi Hugh, I shall have to spend some time looking at these patches, but at LSFMM just a few hours ago, I proposed and nobody objected to removing CONFIG_HIGHPTE. I don't intend to take action on that consensus immediately, so I can certainly wait until your patches are applied, but if this information simplifies what you're doing, feel free to act on it.
