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=-3.9 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 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 737D8C63697 for ; Tue, 27 Oct 2020 16:06:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0ABF12225E for ; Tue, 27 Oct 2020 16:06:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="V4L7qO2R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1806110AbgJ0QFy (ORCPT ); Tue, 27 Oct 2020 12:05:54 -0400 Received: from merlin.infradead.org ([205.233.59.134]:51744 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1802140AbgJ0Ppp (ORCPT ); Tue, 27 Oct 2020 11:45:45 -0400 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=vS0WQyA1FoopoJORMaYRyN4NqXEhBztCAPdnx7wzKRQ=; b=V4L7qO2R2JS6pfVWkQymVaWMwj RmjAu/+KnCywtjZeZK9NVh+x0yEmTW0fFmGJ/vI4GFgqyf1KSr4f4DnxLB6XcnZRVvcFTZBE1pU2K PkpcGgFuFuA50BHrE/3PQijXYUPUEo65svNy/X64ptCQF1jsNXjZFOGiJpJo0P34Ms67tBGRFzanp 8qhK0j5vR3gFi3+q5LWdy7qxPPxKMOxw9OuGi9x3Uh3hnFTPSIBHGlcTteCxRDjNRr4QqtZuBgLyt TlcrZhtGUH8hkI1+fqVOmwRdJxetpEJy1Y//hMblbW0QhMYESRv5WcJcwRT6M+E5U/IcQq39HAh3i VVMxcvKw==; 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 1kXRAH-0004XO-B2; Tue, 27 Oct 2020 15:45:37 +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 D08993060F2; Tue, 27 Oct 2020 16:45:33 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id A7876203CF3A9; Tue, 27 Oct 2020 16:45:33 +0100 (CET) Date: Tue, 27 Oct 2020 16:45:33 +0100 From: Peter Zijlstra To: Chris Wilson Cc: linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org, tip-bot2 for Peter Zijlstra , Qian Cai , x86 Subject: Re: [tip: locking/core] lockdep: Fix usage_traceoverflow Message-ID: <20201027154533.GB2611@hirez.programming.kicks-ass.net> References: <20200930094937.GE2651@hirez.programming.kicks-ass.net> <160208761332.7002.17400661713288945222.tip-bot2@tip-bot2> <160379817513.29534.880306651053124370@build.alporthouse.com> <20201027115955.GA2611@hirez.programming.kicks-ass.net> <20201027123056.GE2651@hirez.programming.kicks-ass.net> <160380535006.10461.1259632375207276085@build.alporthouse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <160380535006.10461.1259632375207276085@build.alporthouse.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 27, 2020 at 01:29:10PM +0000, Chris Wilson wrote: > <4> [304.908891] hm#2, depth: 6 [6], 3425cfea6ff31f7f != 547d92e9ec2ab9af > <4> [304.908897] WARNING: CPU: 0 PID: 5658 at kernel/locking/lockdep.c:3679 check_chain_key+0x1a4/0x1f0 Urgh, I don't think I've _ever_ seen that warning trigger. The comments that go with it suggest memory corruption is the most likely trigger of it. Is it easy to trigger?