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 X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0C9BC433E0 for ; Wed, 24 Jun 2020 06:51:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 87B3D2072E for ; Wed, 24 Jun 2020 06:51:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389504AbgFXGvB (ORCPT ); Wed, 24 Jun 2020 02:51:01 -0400 Received: from mx2.suse.de ([195.135.220.15]:57428 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389400AbgFXGvA (ORCPT ); Wed, 24 Jun 2020 02:51:00 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 9307BAD11; Wed, 24 Jun 2020 06:50:58 +0000 (UTC) Date: Wed, 24 Jun 2020 08:50:54 +0200 From: Petr Mladek To: Dmitry Safonov Cc: linux-kernel@vger.kernel.org, Dmitry Safonov <0x7f454c46@gmail.com>, Andy Lutomirski , Borislav Petkov , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Sergey Senozhatsky , Steven Rostedt , Tetsuo Handa , Thomas Gleixner , x86@kernel.org Subject: Re: [PATCH 0/3] x86/dumpstack: Print registers with the same log level as the backtrace Message-ID: <20200624065054.GC8444@alley> References: <20200623162958.331051-1-dima@arista.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200623162958.331051-1-dima@arista.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 2020-06-23 17:29:55, Dmitry Safonov wrote: > show_trace_log_lvl() provides x86 platform-specific way to unwind > backtrace with a given log level. Unfortunately, registers dump(s) are > not printed with the same log level - instead, KERN_DEFAULT is always > used. > > Arista's switches uses quite common setup with rsyslog, where only > urgent messages goes to console (console_log_level=KERN_ERR), everything > else goes into /var/log/ as the console baud-rate often is indecently > slow (9600 bps). > > Backtrace dumps without registers printed have proven to be as useful as > morning standups. Furthermore, in order to introduce KERN_UNSUPPRESSED > (which I believe is still the most elegant way to fix raciness of sysrq[1]) > the log level should be passed down the stack to register dumping > functions. Besides, I have a potential use-case for printing traces > with KERN_DEBUG level [2] (where registers dump shouldn't appear with > higher log level than the backtrace). > > Dmitry Safonov (3): > x86/dumpstack: Add log_lvl to show_iret_regs() > x86/dumpstack: Add log_lvl to __show_regs() > x86/dumpstack: Show registers dump with trace's log level The change makes sense. It is natural next step after adding log_lvl parameter for printing stack traces. For the entire patchset: Acked-by: Petr Mladek Are there any plans to add this also for other architectures, please? Best Regards, Petr