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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Mon, 20 Jun 2022 14:10:20 -0500
Message-ID: <CAHk-=whBSrixcBVoWGnU0eoaksp82gnQ9_1jMNZsCzhLXEgEpw@mail.gmail.com>
Subject: Re: [PATCH] printk/console: Enable console kthreads only when there
 is no boot console left
To:     Petr Mladek <pmladek@suse.com>
Cc:     =?UTF-8?B?TWFyZWsgQmVow7pu?= <kabel@kernel.org>,
        John Ogness <john.ogness@linutronix.de>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Jan Kara <jack@suse.cz>, Peter Zijlstra <peterz@infradead.org>
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On Mon, Jun 20, 2022 at 10:14 AM Petr Mladek <pmladek@suse.com> wrote:
>
> The console kthreads uncovered several races in console drivers.

I really want to make it clear that this was NOT some kind of "races
in drivers".

Console drivers may very well  have intentionally avoided taking locks
for console output, since the printk output was supposed to be
serialized by printk.

Don't try to make this some kind of "buggy drivers" thing. This is on
printk, not on anything else.

Assuming this solves all issues, I'm ok with this approach, but I
really want this to be clearly about printk being buggy, no "blame the
drivers" garbage.

And if there are other issues coming up, we revert the whole thing entirely.

Because printk is too important to play games with, and too important
to try to blame drivers.

               Linus