From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3CAED27280C; Wed, 10 Dec 2025 04:05:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765339544; cv=none; b=eYTERtarWFbuKd7Oy06VaVWpWm7W3YxgU0CdLRnTVDLLQiSYCHEbjpMEZelx2sBNYQE+bOooOssS8DB2Feq7XpxzKg9NzHdXeO6aZ9x4RqWvx4zgL/FDD3lCe8qQ6nwIFLqP8pO5Wof6QaNF2KDZ3H/jyk0qHy0RRJ2z+NmtsLI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765339544; c=relaxed/simple; bh=/pgtDdbLyzsiBNrvqE8WGvAHGF6R2MHfkVKuKRhOpDc=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Q2CjiLLNPj/wJSwfx4hJAQsUpIqm10NBjzQYZTSxodAX12sPa83QucOLG+zM4nX5BtkwjH69aoEIb3zRX/lJ6TWmhAbokYWJjK5BV4uc4A6cYEw9UU25Q4/8zxuVc3970QP4iG6oreeltmURgvYTocymeQp+7n1nwyVeBqHSPKo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eSLSiwyv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eSLSiwyv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6086C4CEF1; Wed, 10 Dec 2025 04:05:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1765339543; bh=/pgtDdbLyzsiBNrvqE8WGvAHGF6R2MHfkVKuKRhOpDc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=eSLSiwyvvuk2jVCHEVC5WEOrgjc26SOeByQu0BTaa5gTYpoDNrwoOKjsAKXt1u6xP 19gPkArZ4u8HzbtaHd7vGEyZH9NlJ+U9w4eKqFpmiVb8saoD+ACIiRQJh9jNJ/4i9/ EKuw9iECrtFHmxqFpGn2/7p8/pPX3HSRRs0f7/IefUjD0DfwjoJVCwCn2amfqXXZtl dxLFEamLg/VOyAUlFVq2VNuMwA6opUgYlVjtSUW3P/PuWdnKGd7nYNIAMRTbQvNFz4 Tve9+KsRJb0B+fDnZK0+yrtQ0qUOmgVt/W2OY8ven4sEmcMGgVyy8cEx9rmQ+erVAN zq1/PIOVKmH0A== Date: Wed, 10 Dec 2025 13:05:38 +0900 From: Jakub Kicinski To: Breno Leitao Cc: Petr Mladek , Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Shuah Khan , Simon Horman , Jonathan Corbet , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, gustavold@gmail.com, asantostc@gmail.com, calvin@wbinvd.org, kernel-team@meta.com, davej@codemonkey.org.uk Subject: Re: [PATCH net-next 0/4] (no cover subject) Message-ID: <20251210130538.38374707@kernel.org> In-Reply-To: References: <20251128-netconsole_send_msg-v1-0-8cca4bbce9bc@debian.org> <20251201163622.4e50bf53@kernel.org> <4oybtunobxtemenpg2lg7jv4cyl3xoaxrjlqivbhs6zo72hxpu@fqp6estf5mpc> <20251202102442.568f91a7@kernel.org> <7jdruzcpkeyhuudwi6uzg2vsc5mhgpq7qz4ym7vqqmgs7j3524@cvtnzneddg2d> <20251209163745.3d0fcdfe@kernel.org> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 9 Dec 2025 09:46:51 -0800 Breno Leitao wrote: > > I think I was alluding that another option (not saying that it's the > > best but IIUC your requirements it'd be the best fit)): > > > > 5) Add a keepalive configfs knob, if set to a non-zero value netconsole > > will send an empty (?) message at given interval > > > > Pros: > > - truly does not require a user binary to run periodically, netcons > > would set a timer in the kernel > > Cons: > > - does not provide the arbitrary "console bypass" message > > functionality > > This is a good idea if we change it slightly. What about a "ping" > configfs item that send sit when I touch it? > > Something as: > > # echo 1 > /sys/kernel/configs//ping > > And it would ping the host with a predefined "ping" message, and nothing > else. > > That would work, for my current problem, honestly. > > One drawback compared to a more flexible "send_msg" is that I don't have > complete flexibility on the message format. Thus, if I want to pass > extra information such as a Nonce, timestamp, host state, interface > name, health state, it will not be possible, which is fine for now, > given I am NOT planning to use it at this stage. If you still want to tickle it from user space periodically, I guess send_msg is more flexible. I think the main advantage of keepalive would be to remove the need for periodic userspace work.