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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 D0047C282DD for ; Thu, 9 Jan 2020 20:55:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A10F520721 for ; Thu, 9 Jan 2020 20:55:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727963AbgAIUz6 (ORCPT ); Thu, 9 Jan 2020 15:55:58 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:55671 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725763AbgAIUz6 (ORCPT ); Thu, 9 Jan 2020 15:55:58 -0500 Received: from p5b06da22.dip0.t-ipconnect.de ([91.6.218.34] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1ipeqO-00088L-9V; Thu, 09 Jan 2020 21:55:52 +0100 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id C1ABF105BCE; Thu, 9 Jan 2020 21:55:51 +0100 (CET) From: Thomas Gleixner To: Changbin Du Cc: Ingo Molnar , Borislav Petkov , hpa@zytor.com, x86@kernel.org, Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Changbin Du Subject: Re: [PATCH] x86/nmi: remove the irqwork from long duration nmi handler In-Reply-To: <20200101072017.82990-1-changbin.du@gmail.com> References: <20200101072017.82990-1-changbin.du@gmail.com> Date: Thu, 09 Jan 2020 21:55:51 +0100 Message-ID: <877e20bb8o.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Changbin Du writes: > First, printk is NMI context safe now since the safe printk has been > implemented. The safe printk already has an irqwork to make NMI context > safe. > > Second, the NMI irqwork actually does not work if a NMI handler causes > panic by watchdog timeout. This NMI irqwork have no chance to run in such > case, while the safe printk will flush its per-cpu buffer before panic. > > Signed-off-by: Changbin Du Looks about right. Acked-by: Thomas Gleixner