linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Paul E. McKenney" <paulmck@linux.ibm.com>
To: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
	Byungchul Park <byungchul.park@lge.com>,
	Scott Wood <swood@redhat.com>,
	Joel Fernandes <joel@joelfernandes.org>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	rcu <rcu@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Josh Triplett <josh@joshtriplett.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Lai Jiangshan <jiangshanlai@gmail.com>
Subject: Re: [RFC] Deadlock via recursive wakeup via RCU with threadirqs
Date: Sat, 29 Jun 2019 09:55:33 -0700	[thread overview]
Message-ID: <20190629165533.GA3112@linux.ibm.com> (raw)
In-Reply-To: <20190629151236.GA7862@andrea>

On Sat, Jun 29, 2019 at 05:12:36PM +0200, Andrea Parri wrote:
> Hi Steve,
> 
> > As Paul stated, interrupts are synchronization points. Archs can only
> > play games with ordering when dealing with entities outside the CPU
> > (devices and other CPUs). But if you have assembly that has two stores,
> > and an interrupt comes in, the arch must guarantee that the stores are
> > done in that order as the interrupt sees it.
> 
> Hopefully I'm not derailing the conversation too much with my questions
> ... but I was wondering if we had any documentation (or inline comments)
> elaborating on this "interrupts are synchronization points"?

I don't know of any, but I would suggest instead looking at something
like the Hennessey and Patterson computer-architecture textbook.

Please keep in mind that the rather detailed documentation on RCU is a
bit of an outlier due to the fact that there are not so many textbooks
that cover RCU.  If we tried to replicate all of the relevant textbooks
in the Documentation directory, it would be quite a large mess.  ;-)

							Thanx, Paul


  reply	other threads:[~2019-06-29 16:55 UTC|newest]

Thread overview: 78+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-26 13:54 [RFC] Deadlock via recursive wakeup via RCU with threadirqs Sebastian Andrzej Siewior
2019-06-26 16:25 ` Paul E. McKenney
2019-06-27  7:47   ` Sebastian Andrzej Siewior
2019-06-27 15:52     ` Paul E. McKenney
2019-06-27 14:24   ` Joel Fernandes
2019-06-27 14:34     ` Steven Rostedt
2019-06-27 15:30       ` Joel Fernandes
2019-06-27 15:37         ` Joel Fernandes
2019-06-27 15:40           ` Sebastian Andrzej Siewior
2019-06-27 15:42             ` Joel Fernandes
2019-06-27 17:43             ` Joel Fernandes
2019-06-27 17:46               ` Joel Fernandes
2019-06-27 18:11                 ` Paul E. McKenney
2019-06-27 18:27                   ` Joel Fernandes
2019-06-27 18:51                     ` Joel Fernandes
2019-06-27 19:14                       ` Paul E. McKenney
2019-06-27 19:15                     ` Paul E. McKenney
2019-06-27 18:30                   ` Paul E. McKenney
2019-06-27 20:45                     ` Paul E. McKenney
2019-06-27 15:55         ` Paul E. McKenney
2019-06-27 16:47           ` Joel Fernandes
2019-06-27 17:38             ` Paul E. McKenney
2019-06-27 18:16               ` Joel Fernandes
2019-06-27 18:41                 ` Paul E. McKenney
2019-06-27 20:17                   ` Scott Wood
2019-06-27 20:36                     ` Paul E. McKenney
2019-06-28  7:31                       ` Byungchul Park
2019-06-28  7:43                         ` Byungchul Park
2019-06-28  8:14                           ` Byungchul Park
2019-06-28  8:24                             ` Byungchul Park
2019-06-28 12:24                               ` Paul E. McKenney
2019-06-28  9:10                           ` Byungchul Park
2019-06-28  9:28                             ` Byungchul Park
2019-06-28 12:21                           ` Paul E. McKenney
2019-06-28 10:40                         ` Byungchul Park
2019-06-28 12:27                           ` Paul E. McKenney
2019-06-28 15:44                           ` Steven Rostedt
2019-06-29 15:12                             ` Andrea Parri
2019-06-29 16:55                               ` Paul E. McKenney [this message]
2019-06-29 18:09                                 ` Andrea Parri
2019-06-29 18:21                                   ` Andrea Parri
2019-06-29 19:15                                   ` Paul E. McKenney
2019-06-29 19:35                                     ` Andrea Parri
2019-06-30 23:55                             ` Byungchul Park
2019-06-28 14:15                       ` Peter Zijlstra
2019-06-28 15:54                         ` Paul E. McKenney
2019-06-28 16:04                           ` Peter Zijlstra
2019-06-28 17:20                             ` Paul E. McKenney
2019-07-01  9:42                               ` Peter Zijlstra
2019-07-01 10:24                                 ` Sebastian Andrzej Siewior
2019-07-01 12:23                                   ` Paul E. McKenney
2019-07-01 14:00                                     ` Peter Zijlstra
2019-07-01 16:01                                       ` Paul E. McKenney
2019-06-28 20:01                         ` Scott Wood
2019-07-01  9:45                           ` Peter Zijlstra
2019-06-28 13:54                   ` Peter Zijlstra
2019-06-28 15:30                     ` Paul E. McKenney
2019-06-28 18:40                       ` Sebastian Andrzej Siewior
2019-06-28 18:52                         ` Paul E. McKenney
2019-06-28 19:24                           ` Joel Fernandes
2019-06-28 20:04                             ` Paul E. McKenney
2019-06-28 21:40                               ` Joel Fernandes
2019-06-28 22:25                                 ` Paul E. McKenney
2019-06-28 23:12                                   ` Joel Fernandes
2019-06-29  0:06                                     ` Paul E. McKenney
2019-06-28 16:40                   ` Joel Fernandes
2019-06-28 16:45                     ` Joel Fernandes
2019-06-28 17:30                       ` Paul E. McKenney
2019-06-28 17:41                         ` Paul E. McKenney
2019-06-28 17:45                         ` Sebastian Andrzej Siewior
2019-06-28 18:07                           ` Joel Fernandes
2019-06-28 18:20                             ` Sebastian Andrzej Siewior
2019-07-01  2:08                               ` Joel Fernandes
2019-06-28 18:22                           ` Paul E. McKenney
2019-06-28 19:29                             ` Joel Fernandes
2019-06-28 20:06                               ` Paul E. McKenney
2019-06-28 18:05                         ` Joel Fernandes
2019-06-28 18:23                           ` 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=20190629165533.GA3112@linux.ibm.com \
    --to=paulmck@linux.ibm.com \
    --cc=andrea.parri@amarulasolutions.com \
    --cc=bigeasy@linutronix.de \
    --cc=byungchul.park@lge.com \
    --cc=jiangshanlai@gmail.com \
    --cc=joel@joelfernandes.org \
    --cc=josh@joshtriplett.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=rcu@vger.kernel.org \
    --cc=rostedt@goodmis.org \
    --cc=swood@redhat.com \
    --cc=tglx@linutronix.de \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).