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 9E5EDC2BA83 for ; Wed, 12 Feb 2020 10:01:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 62C5420873 for ; Wed, 12 Feb 2020 10:01:30 +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="RcqtaBtj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728986AbgBLKB3 (ORCPT ); Wed, 12 Feb 2020 05:01:29 -0500 Received: from merlin.infradead.org ([205.233.59.134]:33092 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728745AbgBLKB3 (ORCPT ); Wed, 12 Feb 2020 05:01:29 -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=vmVcNp5qMZzdUdSZWSizA+92PAY3N8xDElToXt9qO7s=; b=RcqtaBtjoSUkXiIj/AcVat4N5a 5RNdGUDjTDltWOV04YoqWBTWVY6ScTJJl7zSQvvwbHWip8jZOLqI6KirYpqeQB34P+wo6+0aQkMsf koy5kpkUMB5H3LwxseZgp/J4DgvDWplbRsCxdxV34tCe6CioeSUorn1D9JfZWtdyGaqku/9CIKK9g PS8DdE6guOBCllTcj9GwF+4EzZkP+alnSedaO4w4zVYRRiFj7F8kNyCuyNRZIXTqLBtkUzQjqW2ov S34n/4L7+JVhNZPtP8iDvcsBKKMwXVsw9EymHY9JpDpJ2dl+VdyFAqMQiFJXvyUMMsWlz3g/W+iHx 7Beoppmg==; 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 1j1opQ-0006Zo-JN; Wed, 12 Feb 2020 10:01:08 +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 AAFF7300679; Wed, 12 Feb 2020 10:59:17 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 9C8DB2B2A98AF; Wed, 12 Feb 2020 11:01:06 +0100 (CET) Date: Wed, 12 Feb 2020 11:01:06 +0100 From: Peter Zijlstra To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, rostedt@goodmis.org, james.morse@arm.com, will@kernel.org, catalin.marinas@arm.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: <20200212100106.GA14914@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). For ARM64: - apei_claim_sea() - __sdei_handler() - do_serror() - debug_exception_enter() / do_debug_exception() all look dodgy.