From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 20FA74E0B6F; Fri, 9 Oct 2026 13:28:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791552517; cv=none; b=tot9OCbxl23R2OvqzIKlYHB4vuQCkMD2ioV96JoW/2fXc1zFg1pv8qK/TqsRtjzSV5nt6T+03CBI7JL0vk4/AmaoqQFFMXUM/9O0agU0z5g9dKFsNaSnsYDksPBz9M/PfPxsIqb8v1YEpXO0zh+Xm6NOZzrn76IgdhV17ceZvyo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791552517; c=relaxed/simple; bh=y630XFwaVq8fqyb4CaFWQ5+Z6Dk7Xz9k+6pLUlhvk7Y=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=uLq4wmzYmMLT1CORgikisutQD+qDU+Ar7c0T9H4eeM3EH85A72Gc67O/IPw/Zp/grdPt6eCfy8GWYG2YFKS9J6NaX/0xElCl6WqZ2ufd9xbZ/5+P7UTPXDvMxWjjjGYezguLVkFoyVFWXp21akA3LrsKTlWhyKcRnhg6gBSUgoA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=AfWrqWv/; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=aQ/pDhQi; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="AfWrqWv/"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="aQ/pDhQi" From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1791552510; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=y630XFwaVq8fqyb4CaFWQ5+Z6Dk7Xz9k+6pLUlhvk7Y=; b=AfWrqWv/kn1V+yxFZkeyw+4kzga2Jzjxiu9Eb7MeWcC8SZ2EY+mtXAylyNebAksZZJMD/y udP4Ox/j5HME0NrDCc5TJw8M9q/SgeEUvC4XDF+SZvUDHPuc/ry66fdRqlOJ/+j50gAgdp +d04cuAQv9uWhQTs8Asc6v6T+IfcN/ffj11vLEf+UrFJRZg4GDcDdLTbe77tqmfgBo4SZz URrf3nrGDuevnmpAW/eLdL+zrhOj6TlkJzd4TrCiX2t3ELOqigLeJudDTx9dFtNL/O0f9y CQT+QY65CUiL40AoA3VqlMvNlLPjODgYKST2xtEXeUBUlGFTpH4b6OQbhQwS7g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1791552510; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=y630XFwaVq8fqyb4CaFWQ5+Z6Dk7Xz9k+6pLUlhvk7Y=; b=aQ/pDhQibbn93TFWmghqfNViH1ueOCkPYWijtlSSg+8AAYxVPmFzK1kGzB5DqKzH2BwJfN HWB5FsBgsXM1arAw== To: Petr Mladek , Sebastian Andrzej Siewior Cc: Sergey Senozhatsky , Steven Rostedt , Pavel Tikhomirov , Oleg Nesterov , Christian Brauner , oe-lkp@lists.linux.dev, lkp@intel.com, linux-serial@vger.kernel.org, oliver.sang@intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] nbcon/reboot: Flush nbcon consoles synchronously on reboot In-Reply-To: References: <20261008150852.8286-1-pmladek@suse.com> <20261009065152.udyfFRHx@linutronix.de> Date: Fri, 09 Oct 2026 15:34:30 +0206 Message-ID: <87qzhzxatd.fsf@jogness.linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On 2026-10-09, Petr Mladek wrote: > Anyway, IMHO, we should switch to NBCON_PRIO_EMERGENCY for the post-running > states and flush the pending messages immediately. It is more > reliable. It is easy to find the locations when system_state() is set. > And all follow-up printk() calls will try the direct flush so that > they won't rely on an explicit flush. We need to be careful about abusing CPU state in order to get certain functionality. We already have things in place to gracefully switch to atomic after shutting down the printing kthreads. I will not have a chance to seriously look at this until I get back next week. But at a quick glance, it looks like a roll of duct tape. John