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From: Steven Rostedt <rostedt@goodmis.org>
To: "Paul E. McKenney" <paulmck@linux.ibm.com>
Cc: Joel Fernandes <joel@joelfernandes.org>,
	Nikolay Borisov <nborisov@suse.com>,
	linux-kernel@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
	Josh Triplett <josh@joshtriplett.org>,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	linux-doc@vger.kernel.org,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Subject: Re: [PATCH RFC] doc: rcu: remove obsolete (non-)requirement about disabling preemption
Date: Thu, 18 Oct 2018 21:12:45 -0400	[thread overview]
Message-ID: <20181018211245.10baf496@vmware.local.home> (raw)
In-Reply-To: <20181019001932.GR2674@linux.ibm.com>

On Thu, 18 Oct 2018 17:19:32 -0700
"Paul E. McKenney" <paulmck@linux.ibm.com> wrote:

> I figured that whoever calls preempt_enable_no_resched() is taking the
> responsibility for permitting preemption in the near future, and if they
> fail to do so, they will get called on it.  Hard to hide from the latency
> tracer, after all.  ;-)

Correct, and doing a search of preempt_enable_no_resched() I see
there's one in the ftrace ring buffer code, that was added a long time
ago (2008) to fix a recursion bug that no longer exists, and this now
can leak a preemption point.

I'll have to go fix that :-(

-- Steve

  reply	other threads:[~2018-10-19  1:12 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-14 21:29 [PATCH RFC] doc: rcu: remove obsolete (non-)requirement about disabling preemption Joel Fernandes (Google)
2018-10-14 23:17 ` Paul E. McKenney
2018-10-15  2:08   ` Joel Fernandes
2018-10-15  2:13     ` Joel Fernandes
2018-10-15  2:33       ` Paul E. McKenney
2018-10-15  2:47         ` Joel Fernandes
2018-10-15  2:50           ` Joel Fernandes
2018-10-15  6:05           ` Nikolay Borisov
2018-10-15 11:21             ` Paul E. McKenney
2018-10-15 19:39               ` Joel Fernandes
2018-10-15 19:54                 ` Paul E. McKenney
2018-10-15 20:15                   ` Joel Fernandes
2018-10-15 21:08                     ` Paul E. McKenney
2018-10-16 11:26                       ` Paul E. McKenney
2018-10-16 20:41                         ` Joel Fernandes
2018-10-17 16:11                           ` Paul E. McKenney
2018-10-17 18:15                             ` Joel Fernandes
2018-10-17 20:33                               ` Paul E. McKenney
2018-10-18  2:07                                 ` Joel Fernandes
2018-10-18 14:46                                   ` Paul E. McKenney
2018-10-19  0:03                                     ` Joel Fernandes
2018-10-19  0:19                                       ` Paul E. McKenney
2018-10-19  1:12                                         ` Steven Rostedt [this message]
2018-10-19  1:27                                           ` Joel Fernandes
2018-10-19  1:26                                         ` Joel Fernandes
2018-10-19  1:50                                           ` Steven Rostedt
2018-10-19  2:25                                             ` Joel Fernandes
2018-10-19  2:52                                               ` Steven Rostedt
2018-10-19  3:58                                                 ` Joel Fernandes
2018-10-19 12:07                                                   ` Paul E. McKenney
2018-10-19 17:24                                                     ` Joel Fernandes
2018-10-19 18:11                                                       ` Paul E. McKenney

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