From: Steven Rostedt <rostedt@goodmis.org>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
rcu@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com,
dipankar@in.ibm.com, akpm@linux-foundation.org,
mathieu.desnoyers@efficios.com, josh@joshtriplett.org,
tglx@linutronix.de, dhowells@redhat.com, edumazet@google.com,
fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org
Subject: Re: [PATCH tip/core/rcu 1/3] rcu-tasks: *_ONCE() for rcu_tasks_cbs_head
Date: Tue, 18 Feb 2020 17:45:03 -0500 [thread overview]
Message-ID: <20200218174503.3d4e4750@gandalf.local.home> (raw)
In-Reply-To: <20200218202226.GJ2935@paulmck-ThinkPad-P72>
On Tue, 18 Feb 2020 12:22:26 -0800
"Paul E. McKenney" <paulmck@kernel.org> wrote:
> On Tue, Feb 18, 2020 at 09:11:42PM +0100, Peter Zijlstra wrote:
> > On Tue, Feb 18, 2020 at 08:27:19AM -0800, Paul E. McKenney wrote:
> > > On Tue, Feb 18, 2020 at 08:56:48AM +0100, Peter Zijlstra wrote:
> >
> > > > I just took offence at the Changelog wording. It seems to suggest there
> > > > actually is a problem, there is not.
> > >
> > > Quoting the changelog: "Not appropriate for backporting due to failure
> > > being unlikely."
> >
> > That implies there is failure, however unlikely.
> >
> > In this particular case there is absolutely no failure, except perhaps
> > in KCSAN. This patch is a pure annotation such that KCSAN can understand
> > the code.
> >
> > Like said, I don't object to the actual patch, but I do think it is
> > important to call out false negatives or to describe the actual problem
> > found.
>
> I don't feel at all comfortable declaring that there is absolutely
> no possibility of failure.
Perhaps wording it like so:
"There's know known issue with the current code, but the *_ONCE()
annotations here makes KCSAN happy, allowing us to focus on KCSAN
warnings that can help bring about known issues in other code that we
can fix, without being distracted by KCSAN warnings that we do not see
a problem with."
?
-- Steve
next prev parent reply other threads:[~2020-02-18 22:45 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-15 0:24 [PATCH tip/core/rcu 0/3] Tasks-RCU updates for v5.7 Paul E. McKenney
2020-02-15 0:25 ` [PATCH tip/core/rcu 1/3] rcu-tasks: *_ONCE() for rcu_tasks_cbs_head paulmck
2020-02-17 12:38 ` Peter Zijlstra
2020-02-17 18:16 ` Paul E. McKenney
2020-02-18 7:56 ` Peter Zijlstra
2020-02-18 16:27 ` Paul E. McKenney
2020-02-18 20:11 ` Peter Zijlstra
2020-02-18 20:22 ` Paul E. McKenney
2020-02-18 22:45 ` Steven Rostedt [this message]
2020-02-18 22:54 ` Paul E. McKenney
2020-02-18 23:13 ` Steven Rostedt
2020-02-18 23:54 ` Paul E. McKenney
2020-02-19 0:01 ` Joel Fernandes
2020-02-19 0:16 ` Paul E. McKenney
2020-02-19 1:13 ` Joel Fernandes
2020-02-19 1:48 ` Paul E. McKenney
2020-02-17 18:23 ` Joel Fernandes
2020-02-17 18:38 ` Marco Elver
2020-02-17 19:32 ` Joel Fernandes
2020-02-15 0:25 ` [PATCH tip/core/rcu 2/3] rcu: Add missing annotation for exit_tasks_rcu_start() paulmck
2020-02-17 14:44 ` Joel Fernandes
2020-02-17 23:10 ` Paul E. McKenney
2020-02-15 0:25 ` [PATCH tip/core/rcu 3/3] rcu: Add missing annotation for exit_tasks_rcu_finish() paulmck
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=20200218174503.3d4e4750@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=akpm@linux-foundation.org \
--cc=dhowells@redhat.com \
--cc=dipankar@in.ibm.com \
--cc=edumazet@google.com \
--cc=fweisbec@gmail.com \
--cc=jiangshanlai@gmail.com \
--cc=joel@joelfernandes.org \
--cc=josh@joshtriplett.org \
--cc=kernel-team@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=mingo@kernel.org \
--cc=oleg@redhat.com \
--cc=paulmck@kernel.org \
--cc=peterz@infradead.org \
--cc=rcu@vger.kernel.org \
--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 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.