Re: [PATCH 1/2] list: introduce a new cutting helper

On Thu, Jun 13, 2024 at 10:26:11AM +0530, Nilay Shroff wrote:

I am wondering whether we really need the _rcu version of list_cut here? I think that @head could point to an _rcu protected list and that's true for this patch. So there might be concurrent readers accessing @head using _rcu list-traversal primitives, such as list_for_each_entry_rcu().

Yes, I can't see how this works for a RCU lists without very careful memory ordering.

Btw, another thing - the old vs new list ordering is reversed vs list_splice*, which is a bit confusing (as are the parameter names both for list_splice* and this new helper). Can you switch them around to match?