Received: by 2002:a05:6359:c8b:b0:c7:702f:21d4 with SMTP id go11csp1195032rwb; Fri, 23 Sep 2022 09:18:17 -0700 (PDT) X-Google-Smtp-Source: AMsMyM6gAKy/M/rwtFgbZQOZcNYOJB/C4mtS/NGOm0xj7jTGomf3Lxn7UTE+Nh8DsxQnOWhWfBrg X-Received: by 2002:a17:907:a0c6:b0:77d:7ad3:d05f with SMTP id hw6-20020a170907a0c600b0077d7ad3d05fmr7709974ejc.734.1663949896878; Fri, 23 Sep 2022 09:18:16 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1663949896; cv=none; d=google.com; s=arc-20160816; b=UzOvhVTG9R4tJSmoqH7FPA66LM3ql9d+NOvaK0BHK/YVNRBWMWQHzK8/Or0GfeWhRb dhE66G8ugU28r5lf2IUVKvZRzTLQ8z98Lo4mBIUuUF6BWSuD9ahpSrwNDag5rCdKxGL8 Mb/y9X0i5GgBN5AKXGgDU01Yu8nWOGoOZ59VVEBjKC3Z1VzqUeRi6fvHm+lFuXaeiXV8 NfpJaXh/3RH9VLeSm6zR+JSH6DMQgDRvy90EjlzG55E3QVx4HQ4smRDmiNw5+XK3VVCS PJabgUPoo2mlqyj8VgtA/iFW+6/E/ajfAUvb6i5q//iz4k5N225xZbSa/T641bQSvWDo zbNw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:subject:cc:to:from:date; bh=/LHvDuPhVwTPoZmg1CRtquBEijv4B/h11PhjD2LXdGA=; b=mAk/IH2on8/zXVjb28RW6uUBwzKX+psmAqE2SPjVHm1NePf/LkV4fW1ucbCuj4HRBK 5JKzDePPFf7oo833FbxalQR0AGzBPGAjJSBZY0F4nCu1wVb09XY0K0KPMIq7sQLRbSfc 4UyEJHRg6jAccd7wO6g1fXmTr2K0zxHvVbXeCKo+67oBDkmkbJ3Hct6GyvCHywng6WkH Jfo4TpAduwrw8QLuBgs/ToLFjp3gNluEJS+XpyIsJ0upjU6p6rvA9O6PZZ0ma8Ix4k3D QM3e5E+d6DEZCNEOY10SdSnCbR2C2bhTts7hgGldADgJxPGjuejmXK9PysF0MriFzVtu 2Mdg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id s3-20020a17090699c300b0077ffa45c01esi5624106ejn.725.2022.09.23.09.17.50; Fri, 23 Sep 2022 09:18:16 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232608AbiIWPaO (ORCPT + 99 others); Fri, 23 Sep 2022 11:30:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231864AbiIWPaL (ORCPT ); Fri, 23 Sep 2022 11:30:11 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03B4A9FAB5 for ; Fri, 23 Sep 2022 08:30:10 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id AD6CFB80B3A for ; Fri, 23 Sep 2022 15:30:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 545E4C433C1; Fri, 23 Sep 2022 15:30:04 +0000 (UTC) Date: Fri, 23 Sep 2022 11:31:07 -0400 From: Steven Rostedt To: John Ogness Cc: Thomas Gleixner , LKML , Petr Mladek , Sergey Senozhatsky , Linus Torvalds , Peter Zijlstra , "Paul E. McKenney" , Daniel Vetter , Greg Kroah-Hartman , Helge Deller , Jason Wessel , Daniel Thompson , John Kacur , "John B. Wyatt IV" , Sebastian Andrzej Siewior Subject: Re: printk meeting at LPC 2022 Message-ID: <20220923113107.79d3e013@gandalf.local.home> In-Reply-To: <875yheqh6v.fsf@jogness.linutronix.de> References: <20220910221947.171557773@linutronix.de> <87h71cr1gb.fsf@jogness.linutronix.de> <875yheqh6v.fsf@jogness.linutronix.de> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-6.7 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 23 Sep 2022 16:55:28 +0206 John Ogness wrote: > All other consoles could then be tried as a "last hope" at the very > end of panic(), after all records have been flushed to reliable > consoles and when it no longer matters if a console kills the CPU. For > non-panic emergencies (warn, rcu stalls, etc), there may be other > flags that would be needed. I think we may need to check if kexec is involved. We don't want one of these "last hope" consoles to lock up the system preventing kexec to occur. But if there's no kexec, and the system is just going to lock up anyway, then sure go ahead and call the unsafe consoles. -- Steve