From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: "Theodore Y. Ts'o" <tytso@mit.edu>
Cc: "Petr Mladek" <pmladek@suse.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Sergey Senozhatsky" <sergey.senozhatsky.work@gmail.com>,
"Lech Perczak" <l.perczak@camlintechnologies.com>,
"Steven Rostedt" <rostedt@goodmis.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Arnd Bergmann" <arnd@arndb.de>,
"Krzysztof Drobiński" <k.drobinski@camlintechnologies.com>,
"Pawel Lenkow" <p.lenkow@camlintechnologies.com>,
"John Ogness" <john.ogness@linutronix.de>,
"Tejun Heo" <tj@kernel.org>,
"Peter Zijlstra" <peterz@infradead.org>
Subject: Re: Regression in v4.19.106 breaking waking up of readers of /proc/kmsg and /dev/kmsg
Date: Sat, 29 Feb 2020 12:32:53 +0900 [thread overview]
Message-ID: <20200229033253.GA212847@google.com> (raw)
In-Reply-To: <20200228205334.GF101220@mit.edu>
On (20/02/28 15:53), Theodore Y. Ts'o wrote:
> > So, I would still prefer to _revert_ the commit 15341b1dd409749f
> > ("char/random: silence a lockdep splat with printk()"). It calmed
> > down lockdep report. The real life danger is dubious. The warning
> > is printed early when the system is running on single CPU where
> > it could not race.
>
> I'm wondering now if we should revert this commit before 5.6 comes out
> (it landed in 5.6-rc1). "Is much less likely to happen given the
> other random initialization patches" is not the same as "guaranteed
> not to happen".
>
> What do folks think?
Well, my 5 cents, there is nothing that prevents "too-early"
printk_deferred() calls in the future. From that POV I'd probably
prefer to "forbid" printk_deffered() to touch per-CPU deferred
machinery until it's not "too early" anymore. Similar to what we
do in printk_safe::queue_flush_work().
-ss
next prev parent reply other threads:[~2020-02-29 3:34 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-27 11:09 Regression in v4.19.106 breaking waking up of readers of /proc/kmsg and /dev/kmsg Lech Perczak
2020-02-27 12:36 ` Greg Kroah-Hartman
2020-02-27 12:39 ` Lech Perczak
2020-02-27 14:08 ` Lech Perczak
2020-02-28 3:13 ` Sergey Senozhatsky
2020-02-28 9:11 ` John Ogness
2020-02-28 12:02 ` Sergey Senozhatsky
2020-02-28 10:04 ` Petr Mladek
2020-02-28 10:58 ` Greg Kroah-Hartman
2020-02-28 11:32 ` Petr Mladek
2020-02-28 11:39 ` Greg Kroah-Hartman
2020-02-28 13:02 ` Petr Mladek
2020-02-28 13:41 ` Greg Kroah-Hartman
2020-02-28 20:53 ` Theodore Y. Ts'o
2020-02-29 3:32 ` Sergey Senozhatsky [this message]
2020-02-29 4:08 ` Sergey Senozhatsky
2020-02-29 23:47 ` Steven Rostedt
2020-03-01 5:22 ` Sergey Senozhatsky
2020-03-02 9:49 ` Petr Mladek
2020-03-02 9:59 ` Sergey Senozhatsky
2020-02-28 11:49 ` Sergey Senozhatsky
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