From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Eric Dumazet <eric.dumazet@gmail.com>,
linux-kernel@vger.kernel.org, mingo@elte.hu,
laijs@cn.fujitsu.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, josh@joshtriplett.org, niv@us.ibm.com,
tglx@linutronix.de, dhowells@redhat.com, edumazet@google.com,
darren@dvhart.com, sbw@mit.edu
Subject: Re: [PATCH] rcu: Is it safe to enter an RCU read-side critical section?
Date: Wed, 11 Sep 2013 08:23:31 -0700 [thread overview]
Message-ID: <20130911152331.GZ3966@linux.vnet.ibm.com> (raw)
In-Reply-To: <20130911102607.16a3da91@gandalf.local.home>
On Wed, Sep 11, 2013 at 10:26:07AM -0400, Steven Rostedt wrote:
> On Wed, 11 Sep 2013 07:13:02 -0700
> "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote:
>
> > On Mon, Sep 09, 2013 at 03:34:26PM -0700, Paul E. McKenney wrote:
> > > On Mon, Sep 09, 2013 at 05:59:17PM -0400, Steven Rostedt wrote:
> > > > On Mon, 9 Sep 2013 17:40:26 -0400
> > > > Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> > > >
> > > > > Agreed. So how about rcu_is_online() ?
> > > >
> > > > Nope, what about all_your_base_are_belong_to_rcu()?
> > >
> > > Let's see if I can remember the candidates...
> > >
> > > rcu_is_cpu_idle() # reversed sense from the others
> > > rcu_is_ignored() # reversed sense from the others
> > > rcu_is_not_active() # reversed sense from the others
> > > rcu_is_watching_cpu()
> > > rcu_read_check()
> > > rcu_is_active()
> > > rcu_is_active_local()
> > > rcu_is_online()
> > > rcu_is_watching_task()
> > > rcu_is_watching_thread()
> > > rcu_is_watching_you()
> > > all_your_base_are_belong_to_rcu()
> > > rcu_is_active_loco()
> > > rcu_kilroy_was_here()
> > >
> > > Maybe I should just lock them all in a room overnight and see which
> > > are still alive in the morning.
> >
> > And after treating injuries, the survivor is rcu_is_watching().
> >
>
> But, but, but...
>
> That wasn't one of the contenders!
>
> What happened? Did rcu_is_watching_cpu(), rcu_is_watching_task(),
> rcu_is_watching_thread() and rcu_is_watching_you() all get together to
> gang up on the others, and then combined to be one?
>
> It's another Iraq! Several segments joined together by an outside
> force and they don't play well together. And like Iraq (and the US),
> hidden inside of this "community" is "rcu_is_watching_you"!
C'mon, Steven! I did say "after treating injuries"! In the opinion
of the surgeon, the only option was to ampute what was left of either
the _cpu(), _task(), _thread(), or _you(). Heck, the damage was so
severe that we couldn't even tell which one it was!
Thanx, Paul
next prev parent reply other threads:[~2013-09-11 15:24 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-05 19:52 [PATCH] rcu: Is it safe to enter an RCU read-side critical section? Paul E. McKenney
2013-09-05 20:25 ` Steven Rostedt
2013-09-05 20:59 ` Paul E. McKenney
2013-09-05 21:05 ` Paul E. McKenney
2013-09-05 23:40 ` Steven Rostedt
2013-09-06 10:59 ` Frederic Weisbecker
2013-09-06 15:18 ` Paul E. McKenney
2013-09-06 15:33 ` Steven Rostedt
2013-09-06 16:40 ` Frederic Weisbecker
2013-09-06 16:52 ` Steven Rostedt
2013-09-06 16:58 ` Paul E. McKenney
2013-09-06 17:00 ` Frederic Weisbecker
2013-09-06 17:16 ` Steven Rostedt
2013-09-06 17:52 ` Paul E. McKenney
2013-09-06 17:56 ` Paul E. McKenney
2013-09-06 18:21 ` Steven Rostedt
2013-09-07 0:49 ` Paul E. McKenney
2013-09-07 1:19 ` Mathieu Desnoyers
2013-09-08 1:55 ` Paul E. McKenney
2013-09-09 10:56 ` Peter Zijlstra
2013-09-06 17:21 ` Eric Dumazet
2013-09-06 17:41 ` Paul E. McKenney
2013-09-06 18:59 ` Frederic Weisbecker
2013-09-06 20:38 ` Paul E. McKenney
2013-09-09 10:53 ` Peter Zijlstra
2013-09-09 12:13 ` Frederic Weisbecker
2013-09-09 12:39 ` Steven Rostedt
2013-09-09 12:45 ` Frederic Weisbecker
2013-09-09 12:55 ` Steven Rostedt
2013-09-09 13:08 ` Frederic Weisbecker
2013-09-09 13:21 ` Steven Rostedt
2013-09-09 13:29 ` Paul E. McKenney
2013-09-09 13:29 ` Steven Rostedt
2013-09-09 13:37 ` Peter Zijlstra
2013-09-09 13:48 ` Paul E. McKenney
2013-09-09 14:40 ` Frederic Weisbecker
2013-09-09 15:20 ` Steven Rostedt
2013-09-09 15:39 ` Steven Rostedt
2013-09-09 16:03 ` Frederic Weisbecker
2013-09-09 16:09 ` Paul E. McKenney
2013-09-09 16:30 ` Steven Rostedt
2013-09-09 16:56 ` Paul E. McKenney
2013-09-09 16:21 ` Peter Zijlstra
2013-09-09 13:45 ` Frederic Weisbecker
2013-09-09 13:56 ` Paul E. McKenney
2013-09-09 14:16 ` Steven Rostedt
2013-09-09 16:17 ` Paul E. McKenney
2013-09-09 16:34 ` Steven Rostedt
2013-09-09 16:58 ` Paul E. McKenney
2013-09-09 17:06 ` Steven Rostedt
2013-09-09 17:45 ` Paul E. McKenney
2013-09-09 17:29 ` Mathieu Desnoyers
2013-09-09 17:56 ` Paul E. McKenney
2013-09-09 18:36 ` Steven Rostedt
2013-09-09 18:50 ` Paul E. McKenney
2013-09-09 21:40 ` Mathieu Desnoyers
2013-09-09 21:59 ` Steven Rostedt
2013-09-09 22:34 ` Paul E. McKenney
2013-09-11 14:13 ` Paul E. McKenney
2013-09-11 14:26 ` Steven Rostedt
2013-09-11 15:23 ` Paul E. McKenney [this message]
2013-09-11 15:49 ` Steven Rostedt
2013-09-11 16:03 ` Paul E. McKenney
2013-09-09 13:14 ` Peter Zijlstra
2013-09-09 13:29 ` Frederic Weisbecker
2013-09-09 13:41 ` Steven Rostedt
2013-09-09 13:49 ` Frederic Weisbecker
2013-09-09 13:50 ` Paul E. McKenney
2013-09-09 13:46 ` Paul E. McKenney
2013-09-09 13:55 ` Steven Rostedt
2013-09-09 16:22 ` Paul E. McKenney
2013-09-09 16:40 ` Steven Rostedt
2013-09-09 17:45 ` Paul E. McKenney
2013-09-09 13:23 ` Paul E. McKenney
2013-09-09 13:36 ` Peter Zijlstra
2013-09-09 13:53 ` Paul E. McKenney
2013-09-09 16:18 ` Peter Zijlstra
2013-09-09 14:49 ` Christoph Lameter
2013-09-09 15:08 ` Peter Zijlstra
2013-09-09 15:24 ` Christoph Lameter
2013-09-09 15:41 ` Steven Rostedt
2013-09-09 15:47 ` Steven Rostedt
2013-09-09 16:00 ` Ingo Molnar
2013-09-09 16:03 ` Steven Rostedt
2013-09-09 16:11 ` Ingo Molnar
2013-09-10 21:37 ` Christoph Lameter
2013-09-12 6:39 ` Ingo Molnar
2013-09-12 14:20 ` Christoph Lameter
2013-09-10 21:28 ` Christoph Lameter
2013-09-12 6:38 ` Ingo Molnar
2013-09-12 14:43 ` Christoph Lameter
2013-09-09 16:15 ` Peter Zijlstra
2013-09-10 4:07 ` Mike Galbraith
2013-09-09 13:36 ` Steven Rostedt
2013-09-09 14:21 ` Peter Zijlstra
2013-09-09 16:26 ` Paul E. McKenney
2013-09-09 16:42 ` Steven Rostedt
2013-09-09 16:59 ` Paul E. McKenney
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