From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=193.142.43.55 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793905302; b=G3XpDU6U/v1oXGcn1xTQ2JMkm0TH+9JmXkcnGxpsIAkacSMWW4Pfld+VqlCeQGpn5rVG DTymTQvT1p5AHyJ+Xuh/r0v3ySVjK51sO11ekQu0TNUVCppfG41KDwQHk6k2IfRnSa77K 9IAMYAILAdu8BIiBejkObtpQNsCme7PxOgV/VUc2KptztdK8J8wqfxiFtepvXt6cZnkM7 YTBsVUQHMcCDa+LoxTxcoOQCPo/1Pfn0kkIbuKUP1FayxpKkFRdEi+nG6kjmmIxRn+TBx uWvbgHFVOp9gKr/M7f6gOLwcZWMLkeQppRfqbthTAYmPXA4s4HEIhG8dGhC+wk6CsLA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793905302; h=DMARC-Filter:From:DKIM-Signature:DKIM-Signature:To:Cc:Subject: In-Reply-To:References:Date:Message-ID:MIME-Version:Content-Type; bh=OmR/Ycb/8Y1Gv4EyGNP8sFc8583lU5p/wM5MZManZrw=; b=uAaKETE3udlzMpf/BpCH3DXm1ibMn619Z9WPqKv4ltSVJ/c00M8AJv3pnHnb+7RqLtyC wtbguMgfAgSnYs/91e1vbQCsM7dcrHralsMdx8E2orVlKGDkZq0pwd+tObopf9M02130t f+491RHrzHeHBxWV/piHPF/3vjqLwBY2xVDs9+0z4r2MpwaWDHAzpfNdRbsYmhtpIgVkt k5NX9FLVZxYQSBA1PLbxnArPl67Lkqv7dc+iogWSkwxTNDm67udHRfYgruGKMa6MkMzRx VSl4n4JUIusgtTbCYK6OAODyux9vs1YnPC0N/GkYbU7FueZzLNGVJ7iDMjBwqGUbzqA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=rsa-sha256 header.s=2020 header.b=LlYlOjYc; dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b=SZyH+mLf; arc=none smtp.remote-ip=193.142.43.55 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 91F8B606A31B for ; Thu, 5 Nov 2026 19:01:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 91F8B606A31B 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, unprotected) header.d=linutronix.de header.i=@linutronix.de header.a=rsa-sha256 header.s=2020 header.b=LlYlOjYc; dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b=SZyH+mLf From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1793905298; 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=OmR/Ycb/8Y1Gv4EyGNP8sFc8583lU5p/wM5MZManZrw=; b=LlYlOjYcgTaR2ydF9P3PnbHrJ3oHUEtbis8kWfcJIzIE9GEltPduHQwvHQWK9Uxammc+aI Uqk9LA1ISy2iagJsG8KsMhDqbL0vi/7PtwRWXn3nsobAaEiAVSo/9wUumyQ/n1+LSlrqa6 5tZwDG4rTEGvDKq7u6f7JlOi1fKhS9BaIZv+RPcPjprBYkf00i9eIbBW6do6YN11sy3tK7 bHaS3py0Bu1NeeyzW6XDlFEpqgt6uNPG6zXY4l/gIVvS4cmZW56Ff0grhRUQYoUbNbSM99 l0QqwCOggK6+oHxRkcrS+iXE1TGUn4Vk8BJvck7wxz8JyK0QJo0KdCX6Gjl7gQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1793905298; 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=OmR/Ycb/8Y1Gv4EyGNP8sFc8583lU5p/wM5MZManZrw=; b=SZyH+mLfKrYKn4Y+0L/y2LmINzZbZjr+vNkfKJOGisH23bu7A+0jEwuN9iU9ucpsWWoQxb H2XuH5n9Jq7KMVCg== To: Petr Mladek Cc: Breno Leitao , Ryan Roberts , Andrew Morton , Steven Rostedt , Sergey Senozhatsky , Rio , linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v1] panic: Flush unsafe consoles before panic reboot In-Reply-To: References: <87a4nwyiaw.fsf@jogness.linutronix.de> <874ie4y5mw.fsf@jogness.linutronix.de> <87v76e3mcc.fsf@jogness.linutronix.de> <8733tgc0b5.fsf@jogness.linutronix.de> Date: Thu, 05 Nov 2026 20:01:38 +0100 Message-ID: <87v76bf6gd.fsf@jogness.linutronix.de> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain On 2026-11-05, Petr Mladek wrote: >> And maybe users want safe drivers (such as 8250) to enter "hope and >> pray mode" on kernel ending sites, which is something even legacy >> consoles could not always do. > > I think that I finally understand your concern. You would like to > add a per-console flag for "debugging" or "safe" mode. But > it might be weird when: > > + netconsole is in the "debugging" mode by default. > > + other serial consoles are in the "safe" mode by default. Yes. Although I would not call it "debugging" and "safe". > I see two solutions: > > 1. Keep all NBCON consoles consistent and allow unsafe takeover > on more locations, independently whether they have safe > or unsafe write_atomic(). > > 2. Allow the unsafe takeover on more locations only for netconsole. > And later allow to set both per-console policies: "debugging" > vs. "safe". And accept that netconsole has different default > policy. > > I personally prefer the 2nd solution. Netconsole has always been > a bit special. And maybe someone would implement the safe write_atomic > in the future which will make it more normal, ... I agree. I am preparing a patch that should allow exactly that and hopefully make my idea with the policies clear. John