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Miller" , Eric Dumazet , Jakub Kicinski , Jonathan Corbet , Paolo Abeni , Randy Dunlap , Sergey Senozhatsky , Shuah Khan , Simon Horman , Steven Rostedt Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-doc@vger.kernel.org, Sam Crossley Subject: Re: [PATCH RFC 0/2] netconsole: allow replaying the printk buffer on demand In-Reply-To: <20261024-netcons-replay-upstream-v1-0-9613f38496e5@gmail.com> References: <20261024-netcons-replay-upstream-v1-0-9613f38496e5@gmail.com> Date: Mon, 26 Oct 2026 10:40:14 +0106 Message-ID: <87fqxskdpl.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 2026-10-24, Sam Crossley wrote: > Netconsole only forwards records while an enabled target and its > transport are available. A target enabled after boot, or one that was > unreachable during a network outage, leaves a gap in the remote log that > cannot currently be recovered. This situation is no different than connecting a UART sometime after boot, or having unplugged a serial cable temporarily during runtime. > This adds a write-only "replay" attribute to the netconsole configfs > subsystem that rewinds the netconsole consoles so the retained ring is > re-sent. I would prefer that we find a more general interface for this. One that can apply to all consoles, not just netconsole. We have a couple console features planned or in discussion: per-console loglevels [0] and per-console unsafe dumping/ordering [1]. Both of these are per-console, meaning they also involve the netconsole. I think we need the netconsole to support a general console interface rather than introducing netconsole-only knobs (particularly when such features could be valid for any console). In the per-console loglevel series Chris Down introduces [2] /sys/class/console/ to sysfs. This is where we would put all the upcoming per-console knobs. I would expect a replay trigger would fit well there. John Ogness [0] https://lore.kernel.org/lkml/cover.1764272407.git.chris@chrisdown.name/ [1] https://lore.kernel.org/lkml/87bj8kkfwk.fsf@jogness.linutronix.de/ [2] https://lore.kernel.org/lkml/84b8d91693e56f6026271bc40553bcb6657ab24d.1764272407.git.chris@chrisdown.name/