Re: db4ead2cd5 ("Default enable RCU list lockdep debugging with .."): WARNING: suspicious RCU usage

From: Joel Fernandes
Date: Mon Apr 06 2020 - 11:23:05 EST


On Mon, Apr 06, 2020 at 08:20:57AM +0530, Madhuparna Bhowmik wrote:
> On Sun, Apr 05, 2020 at 07:52:32AM -0700, Paul E. McKenney wrote:
> > On Sun, Apr 05, 2020 at 06:10:31PM +0800, kernel test robot wrote:
> > > Greetings,
> > >
> > > 0day kernel testing robot got the below dmesg and the first bad commit is
> > >
> > > https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2020.03.21a
> >
> > Is some of the required conversion still left to be done? Or on its
> > way up some other tree?
> >
> > If either of these two, my normal approach would be to hold this commit
> > back in order to give the fixes time to hit mainline.
> >
> > But either way, please let me know!
> >
> Yes, some of the patches are not yet reviewed by maintainers and we will
> resend them. Also, this report reports a few new ones that we haven't
> fixed yet (need some help from maintainers to do so).
> We are working on fixing them. May be holding the commit is a
> good idea.

I am Ok with holding on to the commit for mainline. But I would like it into
linux-next so that we and others can get some more velocity on fixing the
remaining issues (and any maintainers who have not yet accepted patches to
review those). We fixed most of them but there could be some more lurking.
Paul, how does that sound?

Either way, we should consider that this feature is turned on only for
lockdep-enabled kernels so it is only used for debugging.

thanks,

- Joel