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=-2.2 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 21EBBC04EB8 for ; Wed, 12 Dec 2018 09:09:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8BC62086D for ; Wed, 12 Dec 2018 09:09:07 +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="kFH2SLNl" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D8BC62086D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726805AbeLLJJG (ORCPT ); Wed, 12 Dec 2018 04:09:06 -0500 Received: from merlin.infradead.org ([205.233.59.134]:55962 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726242AbeLLJJG (ORCPT ); Wed, 12 Dec 2018 04:09:06 -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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=1K/gSdyRUUVriiomPu/vAxOnqsHCvi3CfN9yXMG9g20=; b=kFH2SLNl5YsaGqKzDdq6DH0/A 9CGxqsegjcfoihBg4wkD9lpTVEBKp5+CyZC6YXAQJC6BFfXhuHDXi6rsHLGm0PN1sDM/on7GNbOEa m8sa1J3TNYZIgBT5+ZjdIlp0wtKLIFTohEizeaheB/JEFmQvCQsborkE+WidHyTowhQfifdmYQwop 8oDg2mxB4SDUMcB9WTMLLFAOciIhcqKce5gq6dJj4g52K7csy3jW9wCBZUU7ZgGThyxLE2ZlBMJHL T4+gFZ75MNT8qsngG28miaMOUMqiKpRumE91HZ4acBnsi+fehRx6dpESJ5AOLRuNm8Czti+Tg2BtT b1CMTIzaQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gX0Vq-0006Up-Rw; Wed, 12 Dec 2018 09:09:03 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id AE6BB2075BF39; Wed, 12 Dec 2018 10:09:01 +0100 (CET) Date: Wed, 12 Dec 2018 10:09:01 +0100 From: Peter Zijlstra To: Derek Basehore Cc: mingo@redhat.com, will.deacon@arm.com, linux-kernel@vger.kernel.org Subject: Re: RFC [PATCH 1/1] locking/lockdep: Fix nest lock warning on unlock Message-ID: <20181212090901.GV5289@hirez.programming.kicks-ass.net> References: <20181212022506.171936-1-dbasehore@chromium.org> <20181212022506.171936-2-dbasehore@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181212022506.171936-2-dbasehore@chromium.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 Tue, Dec 11, 2018 at 06:25:06PM -0800, Derek Basehore wrote: > The function __lock_acquire checks that the nest lock is held passed > in as an argument. The issue with this is that __lock_acquire is used > for internal bookkeeping on lock_release. This produces a false > positive lockdep warning on unlock. Since you explicitly don't need to > hold the nest lock on unlock, this is an issue. Who is triggering this?