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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 A1574C4BA12 for ; Wed, 26 Feb 2020 15:20:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B49624680 for ; Wed, 26 Feb 2020 15:20:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728074AbgBZPUf (ORCPT ); Wed, 26 Feb 2020 10:20:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:58338 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727023AbgBZPUe (ORCPT ); Wed, 26 Feb 2020 10:20:34 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1747E20838; Wed, 26 Feb 2020 15:20:33 +0000 (UTC) Date: Wed, 26 Feb 2020 10:20:31 -0500 From: Steven Rostedt To: Peter Zijlstra Cc: Andy Lutomirski , LKML , linux-arch , Ingo Molnar , Joel Fernandes , Greg KH , gustavo@embeddedor.com, Thomas Gleixner , paulmck@kernel.org, Josh Triplett , Mathieu Desnoyers , Lai Jiangshan , Tony Luck , Frederic Weisbecker , Dan Carpenter , Masami Hiramatsu Subject: Re: [PATCH v4 05/27] x86: Replace ist_enter() with nmi_enter() Message-ID: <20200226102031.15664d19@gandalf.local.home> In-Reply-To: <20200226102758.GV18400@hirez.programming.kicks-ass.net> References: <20200221133416.777099322@infradead.org> <20200221134215.328642621@infradead.org> <20200221202246.GA14897@hirez.programming.kicks-ass.net> <20200224104346.GJ14946@hirez.programming.kicks-ass.net> <20200224112708.4f307ba3@gandalf.local.home> <20200224163409.GJ18400@hirez.programming.kicks-ass.net> <20200224114754.0fb798c1@gandalf.local.home> <20200224213139.GO11457@worktop.programming.kicks-ass.net> <20200224170231.3807931d@gandalf.local.home> <20200226102758.GV18400@hirez.programming.kicks-ass.net> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 26 Feb 2020 11:27:58 +0100 Peter Zijlstra wrote: > On Mon, Feb 24, 2020 at 05:02:31PM -0500, Steven Rostedt wrote: > > > The other is for the hwlat detector that measures the time it was in an > > NMI, as NMIs appear as a hardware latency too. > > Yeah,.. I hate that one. But I ended up with this patch. > > And yes, I know some of those notrace annotations are strictly > unnessecary due to Makefile crap, but having them is _SO_ much easier. > > --- > Subject: x86,tracing: Robustify ftrace_nmi_enter() > From: Peter Zijlstra > Date: Mon Feb 24 23:40:29 CET 2020 > > ftrace_nmi_enter() > trace_hwlat_callback() > trace_clock_local() > sched_clock() > paravirt_sched_clock() > native_sched_clock() > > All must not be traced or kprobed, it will be called from do_debug() > before the kprobe handler. > Acked-by: Steven Rostedt (VMware) -- Steve > Signed-off-by: Peter Zijlstra (Intel) > --- > arch/x86/include/asm/paravirt.h | 2 +- > arch/x86/kernel/tsc.c | 7 +++++-- > include/linux/ftrace_irq.h | 4 ++-- > kernel/trace/trace_clock.c | 2 ++ > kernel/trace/trace_hwlat.c | 4 +++- > 5 files changed, 13 insertions(+), 6 deletions(-) >