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a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1705572328; 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=hEDpkWKYdCUozZVhNgkCxtKawEDN121YeJ3ex11tiD8=; b=jeKWojFvbaF/wh7/AlP9tuOuOPdwNzAU349h4xctVPcY4ren0B2NdZl3WKkdBkyA/Q8iYJ VFutwJS0YiOS/I89EiUdp69FgknAutp4jUGsE9nDKaeTQTejfev3bZUezIQOnJArOh3ddU iYNgpELBJm6ww6af3eYPSYyEr08mVIJL/Bk5KSlrGzuXrsBXx1qEN87qsxYofRFCWrsm+s H7OHPujOziF/Xc8B/3bZE2+GiPhIz+6QQPTaFrjY/LqFzsSf2IP1yLZ6BspAp/DCqXkjgh X+xBerk+pXBvBV7PJ2FReGucifDpliRCl1lNLE4N66/mxoUTEn6Y0wN2RrLnCw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1705572328; 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=hEDpkWKYdCUozZVhNgkCxtKawEDN121YeJ3ex11tiD8=; b=LmHSGiMc9vDiLrpTw0No9fYBbraY19ibzOZe72TFgg9DkVrF9PmApnwpa906vdQG+N79Fs Cj+90yytExTxk9CQ== To: Sreenath Vijayan , corbet@lwn.net, gregkh@linuxfoundation.org, jirislaby@kernel.org, rdunlap@infradead.org, pmladek@suse.com Cc: rostedt@goodmis.org, senozhatsky@chromium.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, taichi.shimoyashiki@sony.com, daniel.palmer@sony.com, anandakumar.balasubramaniam@sony.com, sreenath.vijayan@sony.com Subject: Re: [PATCH v3 2/2] tty/sysrq: Dump printk ring buffer messages via sysrq In-Reply-To: <57daf43c5270f7532b269b9f0e90d126ca012354.1705331453.git.sreenath.vijayan@sony.com> References: <57daf43c5270f7532b269b9f0e90d126ca012354.1705331453.git.sreenath.vijayan@sony.com> Date: Thu, 18 Jan 2024 11:11:27 +0106 Message-ID: <87il3rardk.fsf@jogness.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 On 2024-01-17, Sreenath Vijayan wrote: > When terminal is unresponsive, one cannot use dmesg to view printk > ring buffer messages. Also, syslog services may be disabled, > to check the messages after a reboot, especially on embedded systems. > In this scenario, dump the printk ring buffer messages via sysrq > by pressing sysrq+D. Note that using sysrq+g with kgdb or kdb it is already possible to dump the printk ringbuffer messages. However using this new sysrq+D is much more comfortable, less intrusive, and generally safer. I have no problems with this change. But I guess the tty maintainers will need to speak up about extending the sysrq list. John