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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 C2864C352A4 for ; Wed, 12 Feb 2020 10:08:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EEEA2082F for ; Wed, 12 Feb 2020 10:08:27 +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="OacO3J0j" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729006AbgBLKIZ (ORCPT ); Wed, 12 Feb 2020 05:08:25 -0500 Received: from merlin.infradead.org ([205.233.59.134]:33590 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728152AbgBLKIZ (ORCPT ); Wed, 12 Feb 2020 05:08:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.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=1VYkDOIpAfRD96wLx5w8WHVUHIn+SwJhTrRYn7nKarE=; b=OacO3J0j4acTuklH+KL1mTKc5C TvL5VfnqnUZ+yeRtBivvaLezVa9rgHHg78irGwLLWy9OwpwM829XAG9DUcsILgfBX5CTn/PCGHSiR +9GNKlCPGPBvXt6Yjw/qvqr95aNbvHBprG4hE8MLmm6kcfjEUVsuxwsMJpQQhpNaHRC/aMPGpxZDc DiPGdDyZAMA2ClzM+PYVS6ius6Je18kgHL2whJG9aDOHSnMxnEHoehO9R4rVTr+uovITSfaw5bo+A +jncipPkgEWfP3kGtfMLwf+iA8THHABP9eN/AMbzTInQIRQtvpeP+IrAFOr8BAB+TY4QQMKBuAVAk cYag2zDg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1j1ovu-0006fe-JE; Wed, 12 Feb 2020 10:07:50 +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 0064F300679; Wed, 12 Feb 2020 11:06:00 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 239922026E97A; Wed, 12 Feb 2020 11:07:49 +0100 (CET) Date: Wed, 12 Feb 2020 11:07:49 +0100 From: Peter Zijlstra To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, rostedt@goodmis.org, dalias@libc.org, jcmvbkbc@gmail.com Cc: 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 0/8] tracing vs rcu vs nmi Message-ID: <20200212100749.GC14914@hirez.programming.kicks-ass.net> References: <20200212093210.468391728@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200212093210.468391728@infradead.org> 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 10:32:10AM +0100, Peter Zijlstra wrote: > Hi all, > > These here patches are the result of Mathieu and Steve trying to get commit > 865e63b04e9b2 ("tracing: Add back in rcu_irq_enter/exit_irqson() for rcuidle > tracepoints") reverted again. > > One of the things discovered is that tracing MUST NOT happen before nmi_enter() > or after nmi_exit(). I've only fixed x86, but quickly gone through other > architectures and there is definitely more stuff to be fixed (simply grep for > nmi_enter in your arch). Xtensa and SuperH need to mark their NMI C handler notrace.