From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7614BC4332F for ; Mon, 16 May 2022 14:58:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244818AbiEPO6G (ORCPT ); Mon, 16 May 2022 10:58:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244895AbiEPO4w (ORCPT ); Mon, 16 May 2022 10:56:52 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2EF5B37A9B; Mon, 16 May 2022 07:56:51 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 8A94B21FE9; Mon, 16 May 2022 14:56:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1652713009; h=from:from:reply-to: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=oTDrZeo/UdLI29Tuaw8mlcdG/RkPgJLQM7cePAnlqRg=; b=qMST7ia3BcKl3UtC1W2uQ0qkLBJP5Q7YC0oT0Qsb2KbEzU3Or4Q8r5PYsshuphM/GEHsx/ 3TbgfR0/0E5XpsXnd9OyJN2pbUs6sglf0Hs/rZTi2wLDZTO2OOnHvkd7qA4fAmNZA1vdry 3XHA87WfjJ2L5kh4VZznBS1IZ/1m/S0= Received: from suse.cz (unknown [10.100.201.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 028062C141; Mon, 16 May 2022 14:56:49 +0000 (UTC) Date: Mon, 16 May 2022 16:56:41 +0200 From: Petr Mladek To: "Guilherme G. Piccoli" Cc: akpm@linux-foundation.org, bhe@redhat.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, coresight@lists.linaro.org, linuxppc-dev@lists.ozlabs.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-edac@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-leds@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-pm@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, linux-tegra@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, netdev@vger.kernel.org, openipmi-developer@lists.sourceforge.net, rcu@vger.kernel.org, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org, kernel-dev@igalia.com, kernel@gpiccoli.net, halves@canonical.com, fabiomirmar@gmail.com, alejandro.j.jimenez@oracle.com, andriy.shevchenko@linux.intel.com, arnd@arndb.de, bp@alien8.de, corbet@lwn.net, d.hatayama@jp.fujitsu.com, dave.hansen@linux.intel.com, dyoung@redhat.com, feng.tang@intel.com, gregkh@linuxfoundation.org, mikelley@microsoft.com, hidehiro.kawai.ez@hitachi.com, jgross@suse.com, john.ogness@linutronix.de, keescook@chromium.org, luto@kernel.org, mhiramat@kernel.org, mingo@redhat.com, paulmck@kernel.org, peterz@infradead.org, rostedt@goodmis.org, senozhatsky@chromium.org, stern@rowland.harvard.edu, tglx@linutronix.de, vgoyal@redhat.com, vkuznets@redhat.com, will@kernel.org Subject: Re: [PATCH 25/30] panic, printk: Add console flush parameter and convert panic_print to a notifier Message-ID: References: <20220427224924.592546-1-gpiccoli@igalia.com> <20220427224924.592546-26-gpiccoli@igalia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220427224924.592546-26-gpiccoli@igalia.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 2022-04-27 19:49:19, Guilherme G. Piccoli wrote: > Currently the parameter "panic_print" relies in a function called > directly on panic path; one of the flags the users can set for > panic_print triggers a console replay mechanism, to show the > entire kernel log buffer (from the beginning) in a panic event. > > Two problems with that: the dual nature of the panic_print > isn't really appropriate, the function was originally meant > to allow users dumping system information on panic events, > and was "overridden" to also force a console flush of the full > kernel log buffer. It also turns the code a bit more complex > and duplicate than it needs to be. > > This patch proposes 2 changes: first, we decouple panic_print > from the console flushing mechanism, in the form of a new kernel > core parameter (panic_console_replay); we kept the functionality > on panic_print to avoid userspace breakage, although we comment > in both code and documentation that this panic_print usage is > deprecated. > > We converted panic_print function to a panic notifier too, adding > it on the panic informational notifier list, executed as the final > callback. This allows a more clear code and makes sense, as > panic_print_sys_info() is really a panic-time only function. > We also moved its code to kernel/printk.c, it seems to make more > sense given it's related to printing stuff. I really like both changes. Just please split it them into two patchset. I mean one patch for the new "panic_console_replay" parameter and 2nd that moves "printk_info" into the notifier. Best Regards, Petr