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From:   David Laight <David.Laight@ACULAB.COM>
To:     'Petr Mladek' <pmladek@suse.com>,
        Linus Torvalds <torvalds@linux-foundation.org>
CC:     Sergey Senozhatsky <senozhatsky@chromium.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        John Ogness <john.ogness@linutronix.de>,
        "Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        Thomas Gleixner <tglx@linutronix.de>, Jan Kara <jack@suse.cz>,
        Peter Zijlstra <peterz@infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [GIT PULL] printk for 5.20
Thread-Topic: [GIT PULL] printk for 5.20
Thread-Index: AQHYpbiurCjhEtlBF0OMnCiDcM8gDa2aL60w
Date:   Mon, 1 Aug 2022 15:45:13 +0000
Message-ID: <16ef8dbc4bdf4120b046ebacaf1f3cf2@AcuMS.aculab.com>
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> - Completely disable printing on consoles with CONFIG_RT. They break
>   RT guarantees. They are too slow to be called with raw spinlocks.
>   They can't be called with normal spinlocks in an atomic context because
>   RT spinlocks might sleep. It is going to get fixed by the kthreads and
>   atomic consoles. In the meantime, the debugging of CONFIG_RT kernel
>   will be possible only by the user space kernel log readers.

SYSV used to be like that if you were running syslogd.
Used to make debugging some issues completely impossible.

	David

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