From: "Paul E. McKenney" <paulmck@linux.ibm.com>
To: Scott Wood <swood@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Juri Lelli <juri.lelli@redhat.com>,
Clark Williams <williams@redhat.com>,
linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting
Date: Thu, 27 Jun 2019 11:00:07 -0700 [thread overview]
Message-ID: <20190627180007.GA27126@linux.ibm.com> (raw)
In-Reply-To: <8462f30720637ec0da377aa737d26d2cad424d36.camel@redhat.com>
On Wed, Jun 26, 2019 at 11:49:16AM -0500, Scott Wood wrote:
> On Wed, 2019-06-26 at 11:08 -0400, Steven Rostedt wrote:
> > On Fri, 21 Jun 2019 16:59:55 -0700
> > "Paul E. McKenney" <paulmck@linux.ibm.com> wrote:
> >
> > > I have no objection to the outlawing of a number of these sequences in
> > > mainline, but am rather pointing out that until they really are outlawed
> > > and eliminated, rcutorture must continue to test them in mainline.
> > > Of course, an rcutorture running in -rt should avoid testing things that
> > > break -rt, including these sequences.
> >
> > We should update lockdep to complain about these sequences. That would
> > "outlaw" them in mainline. That is, after we clean up all the current
> > sequences in the code. And we also need to get Linus's approval of this
> > as I believe he was against enforcing this in the past.
>
> Was the opposition to prohibiting some specific sequence? It's only certain
> misnesting scenarios that are problematic. The rcu_read_lock/
> local_irq_disable restriction can be dropped with the IPI-to-self added in
> Paul's tree. Are there any known instances of the other two (besides
> rcutorture)?
Given the failure scenario Sebastian Siewior reported today, there
apparently are some, at least when running threaded interrupt handlers.
Thanx, Paul
next prev parent reply other threads:[~2019-06-27 18:00 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-19 1:19 [PATCH RT 0/4] Address rcutorture issues Scott Wood
2019-06-19 1:19 ` [PATCH RT 1/4] rcu: Acquire RCU lock when disabling BHs Scott Wood
2019-06-20 20:53 ` Paul E. McKenney
2019-06-20 21:06 ` Scott Wood
2019-06-20 21:20 ` Paul E. McKenney
2019-06-20 21:38 ` Scott Wood
2019-06-20 22:16 ` Paul E. McKenney
2019-06-19 1:19 ` [PATCH RT 2/4] sched: migrate_enable: Use sleeping_lock to indicate involuntary sleep Scott Wood
2019-06-19 1:19 ` [RFC PATCH RT 3/4] rcu: unlock special: Treat irq and preempt disabled the same Scott Wood
2019-06-20 21:10 ` Paul E. McKenney
2019-06-20 21:59 ` Scott Wood
2019-06-20 22:25 ` Paul E. McKenney
2019-06-20 23:08 ` Scott Wood
2019-06-22 0:26 ` Paul E. McKenney
2019-06-22 19:13 ` Paul E. McKenney
2019-06-24 17:40 ` Scott Wood
2019-06-19 1:19 ` [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting Scott Wood
2019-06-20 21:18 ` Paul E. McKenney
2019-06-20 21:43 ` Scott Wood
2019-06-21 16:38 ` Sebastian Andrzej Siewior
2019-06-21 23:59 ` Paul E. McKenney
2019-06-26 15:08 ` Steven Rostedt
2019-06-26 16:49 ` Scott Wood
2019-06-27 18:00 ` Paul E. McKenney [this message]
2019-06-27 20:16 ` Scott Wood
2019-06-27 20:50 ` Paul E. McKenney
2019-06-27 22:46 ` Scott Wood
2019-06-28 0:52 ` Paul E. McKenney
2019-06-28 19:37 ` Scott Wood
2019-06-28 20:24 ` Paul E. McKenney
2019-06-20 19:12 ` [PATCH RT 0/4] Address rcutorture issues Paul E. McKenney
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190627180007.GA27126@linux.ibm.com \
--to=paulmck@linux.ibm.com \
--cc=bigeasy@linutronix.de \
--cc=juri.lelli@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=swood@redhat.com \
--cc=tglx@linutronix.de \
--cc=williams@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.