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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 5416FC282CE for ; Fri, 5 Apr 2019 21:50:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 17BF621855 for ; Fri, 5 Apr 2019 21:50:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726409AbfDEVuS (ORCPT ); Fri, 5 Apr 2019 17:50:18 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:49968 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726167AbfDEVuS (ORCPT ); Fri, 5 Apr 2019 17:50:18 -0400 Received: from p5492e2fc.dip0.t-ipconnect.de ([84.146.226.252] helo=nanos) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1hCWj1-0005X6-5r; Fri, 05 Apr 2019 23:50:15 +0200 Date: Fri, 5 Apr 2019 23:50:14 +0200 (CEST) From: Thomas Gleixner To: Daniel Bristot de Oliveira cc: Linux Kernel Mailing List , Ingo Molnar , Peter Zijlstra , Steven Rostedt , Andy Lutomirski , Clark Williams , x86@kernel.org Subject: Re: [PATCH V2 2/2] trace,x86: Add nmi to the irq_vectors class In-Reply-To: Message-ID: References: <833f2a192b491649e4d46cec51028d07c96bbf5e.1554142415.git.bristot@redhat.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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 On Mon, 1 Apr 2019, Daniel Bristot de Oliveira wrote: > Currently, the irq_vector class of tracepoints does not include the NMI > entry. The NMI was in the first set of tracepoints for IRQs, but it was > dropped off because of the logic of switching IDT when enabling trace[1]. > However, as the switching IDT logic was removed [2], it is possible to add Well, not really. tracepoints inside of do_nmi() have been there for a long time. The nasty part was that the irq_vector patches injected the tracepoints way down in the low level entry code, which caused more problems than it solved including the extra IDT switcheroo. > the NMI tracepoints back. So again we have two tracepoints. One for the entry and one for the handlers. Do we really need both? If so please provide some rationale. > The tracepoints looks like: > -0 [000] d.Z. 179.594315: nmi_entry: vector=2 > -0 [000] d.Z. 179.594396: nmi_exit: vector=2 > > [1] trace,x86: irq vector tracepoint support > https://lwn.net/Articles/555465/ Please use https://lkml.kernel.org/r/$MESSAGE-ID > [2] commit 4b9a8dca0e58 ("x86/idt: Remove the tracing IDT completely") > > Changes from V1: > - Fix a compilation problem when CONFIG_X86_LOCAL_APIC is not set (kbuild test) Please put changes below the '---' separator. They are not part of the final changelog and having them below spares the maintainer the time to remove them manually. Thanks, tglx