From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f47.google.com (mail-ed1-f47.google.com [209.85.208.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7D9C01C7B84 for ; Wed, 7 Aug 2024 12:52:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723035154; cv=none; b=ahUA3EboX3I9ZUzq9gldhLUoTjZrS5rsn23gmqPrj3ZCb6reggzIa3Et62zzG3W33C/W7rsplmp47heYPRWGRbTc8c3Hj4FwQKWqIjdM42qlZByvEXFR/YjEaHLE9n6rDYOaSh8ynFpQWlB+fAGQjpb+ObmFlHG19gpKq/k+VeE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723035154; c=relaxed/simple; bh=LcvzdZGqvLUxPLQy/Emc/rVY2KjEO+lXOYpXerzIsJY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HymQ/A1YKHpd1TUfslIZqPJvsVVKKGEBWfEj2YKAc5qg+UxvzZkjkRBKjNajxBDImCXBBQ9fpQDZckNv++G8f5hUHxh/IBmZbK8VGvi52GYq6z9iBK1FxrJPW4iX/Y7cpvh8lkK/RwjesnlS+U0Pt0M4vKhwBJvlElfueW+/SNY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b=T/WYc4Ks; arc=none smtp.client-ip=209.85.208.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=suse.com header.i=@suse.com header.b="T/WYc4Ks" Received: by mail-ed1-f47.google.com with SMTP id 4fb4d7f45d1cf-5ba43b433beso2022626a12.1 for ; Wed, 07 Aug 2024 05:52:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1723035151; x=1723639951; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=iwXz6OLsOsYCk8qCnBsBaDWnPwQwa6ssBiygLxwZuhc=; b=T/WYc4KsoG+9XSXq9Rksnk8IvtDAsffH8OZDpy6/ijXm0UEUZ8aTFwb4xWwUtxKtwR 8xx7bPResjSJmJXIaUN15rVkTRtlS0pXgh8AZnByqh53wnFG8956Tsl9UZUMcSge/9Vk syib6IpYC+eYIgJCX4IoFb/PGqi0jzTvy6SaV/cY/966kfSlL+COdx0DEPFGAbZaOvXB wyyT08PkhOUin4QzZvTQLGRaT/JTSWGP5bYHMBMs1ohQR+JJ4qoOTmYxvRvgfUOhMTl/ +jOwmgOeGZ5E5uRrGWmj9oZu26N76xKLkoiuDKpI35dNdNxpYiH2pTSA+BDfKm49MYlR hihg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723035151; x=1723639951; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=iwXz6OLsOsYCk8qCnBsBaDWnPwQwa6ssBiygLxwZuhc=; b=jARyS81cEwTg/egwWc2bm22+2bdTGs3ECSmAvB4TBV1aZO7JwFhGuIqN6FM69mahgJ Zkcp7gmYSw5ZvAkfjK35HAOgyGWwEWvmeE8yfWAMhMmgq5cKNvCQ/+RPt/duXJaQzC4f HfW6acAe8pQmuyRrVxJc1g67qwMkF4bwOcRa9MblhaTOXiheeXYDRQNW0aTOQvjjwlna 1/iOdTjpy8urKWIQcy90K54TgvELrY7uyUwxRLss2ETQ62K5juQQ9ajFyVshtiSG0FUh rxuj7mp8jsHdBJrLQW8/D5GTi2isguT3/5R+TK1vytt3LiHYA/t5WZvYUaw9wVPuFcwQ 2n+w== X-Forwarded-Encrypted: i=1; AJvYcCWswvsfL8Pzm/87rb8LxgnmfdEUx3kUgN1yOvZx9k25VABWzZWSImlilNo7OnOUBANc9U7nQK37T5wHBYIi/Ah25/Bs/s4zaSenXLOX X-Gm-Message-State: AOJu0YwMnfeWKFH6jDgGtY4LySWW2BmZYcOnKGqg7tivxsL1zDy3v7mo xz7fVFOR1WYaJYU387Fu4e0Wdk9vN/IiMavn27tDubacrc1dnO4eEYAYZEXuq2M= X-Google-Smtp-Source: AGHT+IHxGBKcxT2pFij5aIQagRjSqrhABO8Q4KwkwxnQZ3ngWMjKf3ZZvnAQu6W6xkWHxtP1QeDZpQ== X-Received: by 2002:a17:907:6ea3:b0:a7a:a4be:2f95 with SMTP id a640c23a62f3a-a7dc4fdf818mr1325468966b.5.1723035150607; Wed, 07 Aug 2024 05:52:30 -0700 (PDT) Received: from pathway.suse.cz ([176.114.240.50]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a7dc9d437c6sm636111866b.129.2024.08.07.05.52.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Aug 2024 05:52:30 -0700 (PDT) Date: Wed, 7 Aug 2024 14:52:28 +0200 From: Petr Mladek To: John Ogness Cc: Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org, Greg Kroah-Hartman Subject: Re: [PATCH printk v7 31/35] printk: nbcon: Implement emergency sections Message-ID: References: <20240804005138.3722656-1-john.ogness@linutronix.de> <20240804005138.3722656-32-john.ogness@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; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240804005138.3722656-32-john.ogness@linutronix.de> On Sun 2024-08-04 02:57:34, John Ogness wrote: > From: Thomas Gleixner > > In emergency situations (something has gone wrong but the > system continues to operate), usually important information > (such as a backtrace) is generated via printk(). This > information should be pushed out to the consoles ASAP. > > Add per-CPU emergency nesting tracking because an emergency > can arise while in an emergency situation. > > Add functions to mark the beginning and end of emergency > sections where the urgent messages are generated. > > Perform direct console flushing at the emergency priority if > the current CPU is in an emergency state and it is safe to do > so. > > Note that the emergency state is not system-wide. While one CPU > is in an emergency state, another CPU may attempt to print > console messages at normal priority. > > Also note that printk() already attempts to flush consoles in > the caller context for normal priority. However, follow-up > changes will introduce printing kthreads, in which case the > normal priority printk() calls will offload to the kthreads. > > Co-developed-by: John Ogness > Signed-off-by: John Ogness > Signed-off-by: Thomas Gleixner (Intel) Reviewed-by: Petr Mladek Best Regards, Petr