From: Peter Zijlstra <peterz@infradead.org>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
Ingo Molnar <mingo@redhat.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>, LKML <linux-kernel@vger.kernel.org>,
J Freyensee <james_p_freyensee@linux.intel.com>,
syzkaller <syzkaller@googlegroups.com>,
Kostya Serebryany <kcc@google.com>,
Alexander Potapenko <glider@google.com>,
Sasha Levin <sasha.levin@oracle.com>,
Eric Dumazet <edumazet@google.com>
Subject: Re: tty: deadlock between n_tracerouter_receivebuf and flush_to_ldisc
Date: Wed, 20 Jan 2016 12:44:30 +0100 [thread overview]
Message-ID: <20160120114430.GA25010@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <CACT4Y+aP=F9fVC2q0vX4A=AhA8Mu54p7v9s8gbNh=JJJH3g8oA@mail.gmail.com>
On Wed, Jan 20, 2016 at 10:36:01AM +0100, Dmitry Vyukov wrote:
> +Peter, Ingo, can you please suggest a way to annotate this locking
> pattern to avoid lockdep false positive?
No, because I haven't a clue what the actual problem is.
The report is fairly clear on how:
routelock
&port->buf.lock/1
&o_tty->termios_rwsem/1
&buf->lock
gets established, and shows where we try:
&buf->lock
routelock
Which gives a circle, ergo deadlock.
Show which link is wrong and why, and I can suggest ways of annotating
that.
next prev parent reply other threads:[~2016-01-20 11:44 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-30 10:44 tty: deadlock between n_tracerouter_receivebuf and flush_to_ldisc Dmitry Vyukov
2016-01-15 7:51 ` Dmitry Vyukov
2016-01-15 16:33 ` One Thousand Gnomes
2016-01-15 17:22 ` Dmitry Vyukov
2016-01-20 9:36 ` Dmitry Vyukov
2016-01-20 11:44 ` Peter Zijlstra [this message]
2016-01-20 11:54 ` Dmitry Vyukov
2016-01-20 12:07 ` Peter Zijlstra
2016-01-20 14:58 ` One Thousand Gnomes
2016-01-20 15:16 ` Dmitry Vyukov
2016-01-20 16:32 ` Peter Zijlstra
2016-01-20 2:09 ` J Freyensee
2016-01-20 12:47 ` Jiri Slaby
2016-01-20 13:02 ` Peter Zijlstra
2016-01-20 13:07 ` Dmitry Vyukov
2016-01-20 16:08 ` Peter Hurley
2016-01-20 20:47 ` Peter Hurley
2016-01-21 10:06 ` Dmitry Vyukov
2016-01-21 10:20 ` Peter Zijlstra
2016-01-21 17:51 ` Peter Hurley
2016-01-22 14:10 ` Dmitry Vyukov
2016-01-25 16:56 ` Peter Hurley
2016-01-21 17:43 ` Peter Hurley
2016-02-03 4:24 ` Peter Hurley
2016-02-03 17:32 ` Dmitry Vyukov
2016-02-03 19:09 ` Peter Hurley
2016-02-04 12:39 ` Dmitry Vyukov
2016-02-04 13:17 ` Dmitry Vyukov
2016-02-04 18:46 ` Peter Hurley
2016-02-04 18:48 ` Dmitry Vyukov
2016-02-05 21:22 ` Dmitry Vyukov
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=20160120114430.GA25010@twins.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=dvyukov@google.com \
--cc=edumazet@google.com \
--cc=glider@google.com \
--cc=gnomes@lxorguk.ukuu.org.uk \
--cc=gregkh@linuxfoundation.org \
--cc=james_p_freyensee@linux.intel.com \
--cc=jslaby@suse.com \
--cc=kcc@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=sasha.levin@oracle.com \
--cc=syzkaller@googlegroups.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.