Re: [PATCH v2 01/26] rculist: introduce list_next_or_null_rr_rcu()

From: Linus Torvalds
Date: Fri May 18 2018 - 12:00:36 EST


On Fri, May 18, 2018 at 6:07 AM Roman Pen <roman.penyaev@xxxxxxxxxxxxxxxx>
wrote:

> Function is going to be used in transport over RDMA module
> in subsequent patches.

Does this really merit its own helper macro in a generic header?

It honestly smells more like "just have an inline helper function that is
specific to rdma" to me. Particularly since it's probably just one specific
list where you want this oddly specific behavior.

Also, if we really want a round-robin list traversal macro, this isn't the
way it should be implemented, I suspect, and it probably shouldn't be
RCU-specific to begin with.

Side note: I notice that I should already have been more critical of even
the much simpler "list_next_or_null_rcu()" macro. The "documentation"
comment above the macro is pure and utter cut-and-paste garbage.

Paul, mind giving this a look?

Linus