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 8E87C7E0FF; Wed, 4 Feb 2026 23:06:55 +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=1770246415; cv=none; b=q5Z8m3dW3qXcfb+gWiEpNUSxilEiwlbcxW2dFMqgu0I6hanmIYzuWfwL/o/X5IvBu+oZnrB5dwN52vkQmb8zmP+JFWiSydDuV5ZPVpTzNkASXsxyk4mMyibtF0haGXA5zRuxHYDbdPLnlrc01WU+0qM3tUx/eX+ZZCdywk4DSfE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770246415; c=relaxed/simple; bh=qHTZrVOA6lt1VPG6nShf3Uf1dP+eEJrxjdXR6PNSoNg=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=NSNEQ1emfbTfN6+3SVWRi6LtqVu/Mt1Rjk5aLzVY9/Ve9/MHxSEPHvn3uXS5nAcfJmJHvI/CKgedoJM8qtVMXdEyyYz4eYZrdb9cf4dF4SDcJ1jPiCWMo3rCqv8FGDLcE8spHt6at8T2afjuxblnJp2ibbHvO6hmVRmq86qtJ2s= 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=O2sSR1/S; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=WsFvj53N; 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="O2sSR1/S"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="WsFvj53N" From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1770246413; 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=cpitTzrTVEv/Lc254EiSPn/Xtv+lPFW5oSP6A2bo4CU=; b=O2sSR1/SJAn7Q+nuvB6c5NshuUaPdLp0BdWnApRh21CTLqJ1WfzdRy0zgFEoPNJW8O8oGy yZ/tgkwUC2wZ0DABwQ470Izq6T1tL4i7wur6tWqCCwkqF6GSCuqBclkSdk3VkZwga6+8ck 7rEtZcjVfX83mERB3/KhROhS9U8lIBKFnJoKTKapg/YIJgZfkibxVW+LW329rk7ejXtsR/ uTSH+2Y3it/+XP9CHjwQscG7/nDDEVBiwT/ZgtOLh79jUKcCBYahTxh/4Frk/A/3XDTKb7 JggNRGIouFFDdcKCeUQulxMAMGhTeT58EzmIF8wIy54SG1d1rHBCR38GFNLB8A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1770246413; 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=cpitTzrTVEv/Lc254EiSPn/Xtv+lPFW5oSP6A2bo4CU=; b=WsFvj53Nj2lRIDBhTMdAtzYmYCiGgRLuGdA0991nSsbRBDAkdtfB+6Qpf34fE3nm59/50d dCGC2N8KMM7VkZBA== To: Breno Leitao , Breno Leitao , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , pmladek@suse.com Cc: Greg Kroah-Hartman , Steven Rostedt , Sergey Senozhatsky , Andrew Morton , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, asantostc@gmail.com, efault@gmx.de, gustavold@gmail.com, calvin@wbinvd.org, jv@jvosburgh.net, mpdesouza@suse.com, kernel-team@meta.com, Simon Horman Subject: Re: [PATCH net-next v6 0/4] net: netconsole: convert to NBCON console infrastructure In-Reply-To: <20260203-nbcon-v6-0-985f3bdb3267@debian.org> References: <20260203-nbcon-v6-0-985f3bdb3267@debian.org> Date: Thu, 05 Feb 2026 00:12:52 +0106 Message-ID: <87fr7gp0qb.fsf@jogness.linutronix.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On 2026-02-03, Breno Leitao wrote: > This series adds support for the nbcon (new buffer console) infrastructure > to netconsole, enabling lock-free, priority-based console operations that > are safer in crash scenarios. > > The implementation is introduced in three steps: > > 0) Extend printk to expose CPU and taskname (task->comm) where the > printk originated from. (Thanks John and Petr for the support in > getting this done) > 1) Refactor the message fragmentation logic into a reusable helper function > 2) Extend nbcon support to non-extended (basic) consoles using the same > infrastructure. > > The initial discussion about it appeared a while ago in [1], in order to > solve Mike's HARDIRQ-safe -> HARDIRQ-unsafe lock order warning, and the root > cause is that some hosts were calling IRQ unsafe locks from inside console > lock. > > At that time, we didn't have the CON_NBCON_ATOMIC_UNSAFE yet. John > kindly implemented CON_NBCON_ATOMIC_UNSAFE in 187de7c212e5 ("printk: > nbcon: Allow unsafe write_atomic() for panic"), and now we can > implement netconsole on top of nbcon. > > Important to note that netconsole continues to call netpoll and the > network TX helpers with interrupt disable, given the TX are called with > target_list_lock. > > Netdev maintainers, Petr suggested that this patchset goes through netdev[2] > > Link: https://lore.kernel.org/all/b2qps3uywhmjaym4mht2wpxul4yqtuuayeoq4iv4k3zf5wdgh3@tocu6c7mj4lt/ [1] > Link: https://lore.kernel.org/all/aW9D5M0o9_8hdVvt@pathway.suse.cz/ [2] > > Signed-off-by: Breno Leitao > > --- > Changes in v6: > - Do not select PRINTK_EXECUTION_CTX in NETCONSOLE_DYNAMIC (Jakub) > - Do not make PRINTK_EXECUTION_CTX user visible (Jakub) I am really sorry, but I failed to communicate what I meant about introducing the CONSOLE_HAS_EXECUTION_CTX symbol. As Jakub mentioned, NETCONSOLE_DYNAMIC should just directly select PRINTK_EXECUTION_CTX and get rid of the CONSOLE_HAS_EXECUTION_CTX symbol (like you had in v1). I apologize for the confusion and wasted effort here. John