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=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 45B89C4363D for ; Fri, 2 Oct 2020 18:13:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A436420758 for ; Fri, 2 Oct 2020 18:13:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Zw39RRLM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388270AbgJBSN1 (ORCPT ); Fri, 2 Oct 2020 14:13:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726017AbgJBSN1 (ORCPT ); Fri, 2 Oct 2020 14:13:27 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E07DC0613D0 for ; Fri, 2 Oct 2020 11:13:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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=xhQlY0JkE8VSgRmAWRCxmMRj374+etsiscJ83Nt4YS4=; b=Zw39RRLMQl/FOkrgq8hH60JbY8 EdMSnjWmbLbHts5ChvV6ARnzgTXo77B+srQSxZOjRhzNK+hlqK9U1yyszUXQ4JyblNmWO1qEKDmob VFrylyY1kiqsndysxUQgenxv9p7fnIFk8ewItm4+fuy9HvMvNJ0DMJpnKtDcojNrsGDOZJFLDONI4 ahsqMUg70jlzChgpn6NhmNduuGxqMR4bVSnWad6G4WorNXGVyCXYuPRR26bbZL9EvyX+zVqO0uT/e HLNTlRcbRQCcBv0sb4VYO2vTQvqGg2P1o1jNu1m4FLLdQtkOlW7vGtgU5mgCHTq0VAB1+c39EhY5x ycbd61pw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kOPYV-0002zX-MI; Fri, 02 Oct 2020 18:13:20 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id AC76D980DD5; Fri, 2 Oct 2020 20:13:13 +0200 (CEST) Date: Fri, 2 Oct 2020 20:13:13 +0200 From: Peter Zijlstra To: Steven Rostedt Cc: Thomas Gleixner , "Paul E. McKenney" , LKML Subject: Re: [WARNING] kernel/rcu/tree.c:1058 rcu_irq_enter+0x15/0x20 Message-ID: <20201002181313.GM29142@worktop.programming.kicks-ass.net> References: <20200917131647.2b55ebb1@gandalf.local.home> <20200930181323.GF2628@hirez.programming.kicks-ass.net> <20201002135644.7903d0e5@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201002135644.7903d0e5@gandalf.local.home> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 02, 2020 at 01:56:44PM -0400, Steven Rostedt wrote: > On Wed, 30 Sep 2020 20:13:23 +0200 > Peter Zijlstra wrote: > > > Blergh, IIRC there's header hell that way. The sane fix is killing off > > that trace_*_rcuidle() disease. > > > > But I think this will also cure it. > > I guess you still don't build modules ;-). I had to add a > EXPORT_SYMBOL(lockdep_recursion) to get it to build, and then move the Correct, my regular configs are all without modules. > checks within the irq disabling to get rid of the using cpu pointers within > preemptable code warnings Ah, I think I lost a s/__this_cpu_read/raw_cpu_read/ somewhere. The thing is, if we're preemptible/migratable it will be 0 on both CPUs and it doesn't matter which 0 we read. If it is !0, IRQs will be disabled and we can't get migrated. Anyway, let me go write a Changelog to go with it.