Re: [PATCH RFC 0/5] Remove some notrace RCU APIs

From: Joel Fernandes
Date: Sat May 25 2019 - 04:17:58 EST


On Fri, May 24, 2019 at 11:24:58PM -0400, Steven Rostedt wrote:
> On Fri, 24 May 2019 19:49:28 -0400
> "Joel Fernandes (Google)" <joel@xxxxxxxxxxxxxxxxx> wrote:
>
> > The series removes users of the following APIs, and the APIs themselves, since
> > the regular non - _notrace variants don't do any tracing anyway.
> > * hlist_for_each_entry_rcu_notrace
> > * rcu_dereference_raw_notrace
> >
>
> I guess the difference between the _raw_notrace and just _raw variants
> is that _notrace ones do a rcu_check_sparse(). Don't we want to keep
> that check?

This is true.

Since the users of _raw_notrace are very few, is it worth keeping this API
just for sparse checking? The API naming is also confusing. I was expecting
_raw_notrace to do fewer checks than _raw, instead of more. Honestly, I just
want to nuke _raw_notrace as done in this series and later we can introduce a
sparse checking version of _raw if need-be. The other option could be to
always do sparse checking for _raw however that used to be the case and got
changed in http://lists.infradead.org/pipermail/linux-afs/2016-July/001016.html

thanks a lot,

- Joel

>
> -- Steve