From: "Paul E. McKenney" <paulmck@kernel.org>
To: Qian Cai <cai@redhat.com>
Cc: Boqun Feng <boqun.feng@gmail.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@kernel.org>, x86 <x86@kernel.org>,
linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org,
Linux Next Mailing List <linux-next@vger.kernel.org>,
Stephen Rothwell <sfr@canb.auug.org.au>
Subject: Re: [tip: locking/core] lockdep: Fix lockdep recursion
Date: Wed, 28 Oct 2020 14:02:28 -0700 [thread overview]
Message-ID: <20201028210228.GI3249@paulmck-ThinkPad-P72> (raw)
In-Reply-To: <7cd579ccdacb4f672cf2dc3a0d4553d1845e7ebf.camel@redhat.com>
On Wed, Oct 28, 2020 at 04:08:59PM -0400, Qian Cai wrote:
> On Wed, 2020-10-28 at 08:53 -0700, Paul E. McKenney wrote:
> > On Wed, Oct 28, 2020 at 10:39:47AM -0400, Qian Cai wrote:
> > > On Tue, 2020-10-27 at 20:01 -0700, Paul E. McKenney wrote:
> > > > If I have the right email thread associated with the right fixes, these
> > > > commits in -rcu should be what you are looking for:
> > > >
> > > > 73b658b6b7d5 ("rcu: Prevent lockdep-RCU splats on lock
> > > > acquisition/release")
> > > > 626b79aa935a ("x86/smpboot: Move rcu_cpu_starting() earlier")
> > > >
> > > > And maybe this one as well:
> > > >
> > > > 3a6f638cb95b ("rcu,ftrace: Fix ftrace recursion")
> > > >
> > > > Please let me know if these commits do not fix things.
> > > While those patches silence the warnings for x86. Other arches are still
> > > suffering. It is only after applying the patch from Boqun below fixed
> > > everything.
> >
> > Fair point!
> >
> > > Is it a good idea for Boqun to write a formal patch or we should fix all
> > > arches
> > > individually like "x86/smpboot: Move rcu_cpu_starting() earlier"?
> >
> > By Boqun's patch, you mean the change to debug_lockdep_rcu_enabled()
> > shown below? Peter Zijlstra showed that real failures can happen, so we
>
> Yes.
>
> > do not want to cover them up. So we are firmly in "fix all architectures"
> > space here, sorry!
> >
> > I am happy to accumulate those patches, but cannot commit to creating
> > or testing them.
>
> Okay, I posted 3 patches for each arch and CC'ed you.
Very good! I have acked them.
> BTW, it looks like
> something is wrong on @vger.kernel.org today where I received many of those,
>
> 4.7.1 Hello [216.205.24.124], for recipient address <linux-kernel@vger.kernel.org> the policy analysis reported: zpostgrey: connect: Connection refused
>
> and I can see your previous mails did not even reach there either.
>
> https://lore.kernel.org/lkml/
It does seem to be having some difficulty, and some people are looking
into it. Hopefully soon someone who can actually make the needed
changes. ;-)
Thanx, Paul
prev parent reply other threads:[~2020-10-28 21:42 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <160223032121.7002.1269740091547117869.tip-bot2@tip-bot2>
2020-10-09 13:41 ` [tip: locking/core] lockdep: Fix lockdep recursion Qian Cai
2020-10-09 13:58 ` Paul E. McKenney
2020-10-09 15:30 ` Qian Cai
2020-10-09 16:11 ` Paul E. McKenney
2020-10-09 16:23 ` Peter Zijlstra
2020-10-09 16:37 ` Paul E. McKenney
2020-10-09 17:36 ` Qian Cai
2020-10-09 17:50 ` Paul E. McKenney
2020-10-09 17:54 ` Qian Cai
2020-10-09 18:21 ` Paul E. McKenney
2020-10-12 3:11 ` Boqun Feng
2020-10-12 14:14 ` Qian Cai
2020-10-12 21:28 ` Paul E. McKenney
2020-10-13 10:34 ` Peter Zijlstra
2020-10-13 10:44 ` Peter Zijlstra
2020-10-13 11:25 ` Peter Zijlstra
2020-10-13 16:26 ` Paul E. McKenney
2020-10-13 19:30 ` Paul E. McKenney
2020-10-14 18:34 ` Paul E. McKenney
2020-10-14 21:53 ` Peter Zijlstra
2020-10-14 22:11 ` Paul E. McKenney
2020-10-14 22:39 ` Peter Zijlstra
2020-10-14 23:55 ` Paul E. McKenney
2020-10-15 3:41 ` Paul E. McKenney
2020-10-15 9:49 ` Peter Zijlstra
2020-10-15 9:50 ` Peter Zijlstra
2020-10-15 16:15 ` Paul E. McKenney
2020-10-15 9:52 ` Peter Zijlstra
2020-10-15 16:20 ` Paul E. McKenney
2020-10-15 16:15 ` Paul E. McKenney
2020-10-15 17:23 ` Paul E. McKenney
2020-10-13 16:15 ` Paul E. McKenney
2020-10-13 10:27 ` Peter Zijlstra
2020-10-13 16:24 ` Boqun Feng
2020-10-27 19:31 ` Qian Cai
2020-10-28 3:01 ` Paul E. McKenney
2020-10-28 14:39 ` Qian Cai
2020-10-28 15:53 ` Paul E. McKenney
2020-10-28 20:08 ` Qian Cai
2020-10-28 21:02 ` Paul E. McKenney [this message]
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