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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 31E7CC433E0 for ; Mon, 18 May 2020 08:02:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0365320787 for ; Mon, 18 May 2020 08:02:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="AGCeSWw1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727822AbgERICJ (ORCPT ); Mon, 18 May 2020 04:02:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726489AbgERICI (ORCPT ); Mon, 18 May 2020 04:02:08 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA48EC061A0C for ; Mon, 18 May 2020 01:02:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=OliYoPmApMwDOHWsUxWzzlLoF4O4orV+YLS9RaxjrMw=; b=AGCeSWw1H7TP4HeQRRRncdVmin gN/Q0QiXiisyOOaP2xe8tzMKvo7i2TYWtsGZef48hP4qeBj5G3s3GSVX4IfNpWwDrFcCnBKSL6Y+e VWXRhlRAPHo9FyLbdwFQZ7d87AB80BppaTyhtNLvX0L55U5zIt7vH8Jxbz6dfNyP6IbCEFjcNcp6E TwLtHg6hadv20BwucTHbt37Ki/CZhk/dV4kyZ+RVKlOy9wUUT1gWisClaifFVBPal5xFL5apXaiX6 ZNhsgDf2Byw/3JgnGBboOYDvl4ThYChij6t/zqOTAH6614tdSHq+0Id77u4l9uENdg43xNihknduH EoHbTPKA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jaaiO-0004iF-AJ; Mon, 18 May 2020 08:01:36 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id B2657306089; Mon, 18 May 2020 10:01:33 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 51982200CB610; Mon, 18 May 2020 10:01:33 +0200 (CEST) Date: Mon, 18 May 2020 10:01:33 +0200 From: Peter Zijlstra To: Thomas Gleixner Cc: LKML , x86@kernel.org, "Paul E. McKenney" , Andy Lutomirski , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Steven Rostedt , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Mathieu Desnoyers , Josh Poimboeuf , Will Deacon , Tom Lendacky , Wei Liu , Michael Kelley , Jason Chen CJ , Zhao Yakui Subject: Re: [patch V6 04/37] x86: Make hardware latency tracing explicit Message-ID: <20200518080133.GI2940@hirez.programming.kicks-ass.net> References: <20200515234547.710474468@linutronix.de> <20200515235124.783722942@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200515235124.783722942@linutronix.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 16, 2020 at 01:45:51AM +0200, Thomas Gleixner wrote: > --- a/arch/x86/kernel/nmi.c > +++ b/arch/x86/kernel/nmi.c > @@ -334,6 +334,7 @@ static noinstr void default_do_nmi(struc > __this_cpu_write(last_nmi_rip, regs->ip); > > instrumentation_begin(); > + ftrace_nmi_handler_enter(); > > handled = nmi_handle(NMI_LOCAL, regs); > __this_cpu_add(nmi_stats.normal, handled); > @@ -420,6 +421,7 @@ static noinstr void default_do_nmi(struc > unknown_nmi_error(reason, regs); > > out: > + ftrace_nmi_handler_exit(); > instrumentation_end(); > } Yeah, so I'm confused about this and the previous patch too. Why not do just this? Remove that ftrace_nmi_handler.* crud from nmi_{enter,exit}() and stick it here? Why do we needs the nmi_{enter,exit}_notrace() thing?