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=-5.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 65952C2BA83 for ; Wed, 12 Feb 2020 15:05:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 36DE42168B for ; Wed, 12 Feb 2020 15:05:00 +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="Z8ot2vLL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728393AbgBLPE7 (ORCPT ); Wed, 12 Feb 2020 10:04:59 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:43376 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727526AbgBLPE7 (ORCPT ); Wed, 12 Feb 2020 10:04:59 -0500 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=MDNa4LpUKCpXhbe5C9lELzg7pzo1OMQ9rXl+zV0WZfw=; b=Z8ot2vLL44MRH+4LWg8a1tY03u 7A3aahoVUp7RisA/UlUX2roXx9hWLLMYzFTzd35DW+aL7DMcPzcIWrCaY2vD255k+72XIENisB0Ll uTHNZcZROQS0sSfSSYo3vm7hTDg4PhDnKTzTQogBMFR/e5hraCOLE0ib9k8to/fxz2nAHQh2XZPB9 q4YQirCXemwVhkqdiQGF1yiIxmYnFhBIFplHoW/Cd8a9Sa5CBtcWGjIj4bezLSK5lgSdB+TEfWsCL x4FZPOg39lHi5gM021QhH5WfbYcZtXoEDxh0C8mmVgWKgpUbojJyMZqldNhlaCQafCNCD+YBqSeoQ w+EBN03g==; 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 1j1tZC-0006AV-RX; Wed, 12 Feb 2020 15:04:43 +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 24E7630066E; Wed, 12 Feb 2020 16:02:51 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 387832032662E; Wed, 12 Feb 2020 16:04:40 +0100 (CET) Date: Wed, 12 Feb 2020 16:04:40 +0100 From: Peter Zijlstra To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, mingo@kernel.org, joel@joelfernandes.org, gregkh@linuxfoundation.org, gustavo@embeddedor.com, tglx@linutronix.de, paulmck@kernel.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com Subject: Re: [PATCH 5/8] x86,tracing: Mark debug_stack_{set_zero,reset)() notrace Message-ID: <20200212150440.GT14897@hirez.programming.kicks-ass.net> References: <20200212093210.468391728@infradead.org> <20200212094107.894657838@infradead.org> <20200212092539.135934e1@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200212092539.135934e1@gandalf.local.home> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 12, 2020 at 09:25:39AM -0500, Steven Rostedt wrote: > On Wed, 12 Feb 2020 10:32:15 +0100 > Peter Zijlstra wrote: > > > Because do_nmi() must not call into tracing outside of > > nmi_enter()/nmi_exit(), these functions must be notrace. > > > > Signed-off-by: Peter Zijlstra (Intel) > > --- > > arch/x86/kernel/cpu/common.c | 4 ++-- > > arch/x86/kernel/nmi.c | 6 ++++++ > > 2 files changed, 8 insertions(+), 2 deletions(-) > > > > --- a/arch/x86/kernel/cpu/common.c > > +++ b/arch/x86/kernel/cpu/common.c > > This entire file is notrace: > > arch/x86/kernel/cpu/Makefile: > > CFLAGS_REMOVE_common.o = -pg Urgh, I hate it that that annotation is so hard to find :/ Also, there seem to be various flavours of that Makefile magic around. CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE) is another variant I encountered.