Re: [PATCH v2 rcu/dev 1/2] rcu: Track laziness during boot and suspend

From: Paul E. McKenney
Date: Tue Jan 17 2023 - 16:16:45 EST


On Tue, Jan 17, 2023 at 02:32:24PM -0500, Steven Rostedt wrote:
> On Sun, 15 Jan 2023 16:34:58 -0500
> Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote:
>
> > > > +EXPORT_SYMBOL_GPL(rcu_async_hurry);
> > > >
> > >
> > > Where do you plan on calling these externally, as they are being
> > > marked exported?
> > >
> > > If you allow random drivers to enable this, I can see something
> > > enabling it and hitting an error path that causes it to never disable
> > > it.
> >
> > You mean, just like rcu_expedite_gp() ?
> >
> > > I wouldn't have EXPORT_SYMBOL_GPL() unless you really know that it is
> > > needed externally.
> >
> > At the moment it is not called externally but in the future, it could
> > be from rcutorture. If you see rcu_expedite_gp(), that is exported
> > too. I was just modeling it around that API.
>
> The reason for the export should have been mentioned in the change log if
> the patch is not obvious to why it is being exported.

Would something like this suffice? With attribution, of course.

Export rcu_async_should_hurry(), rcu_async_hurry(), and
rcu_async_relax() for later use by rcutorture.

Thanx, Paul