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=-6.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, 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 C3034C55178 for ; Tue, 27 Oct 2020 12:48:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E65620757 for ; Tue, 27 Oct 2020 12:48:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="CslyLURw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751349AbgJ0Mss (ORCPT ); Tue, 27 Oct 2020 08:48:48 -0400 Received: from merlin.infradead.org ([205.233.59.134]:55546 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S460336AbgJ0Msr (ORCPT ); Tue, 27 Oct 2020 08:48:47 -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=gjjbZadqypxxhM9wzukWN2qeOvcJJziD3fYWXYXTJHM=; b=CslyLURwfU7tNotkiZqpo8m9mJ lzUB2dk42CCIjjVstpL9M6OJH1bGDwygjUkGS5aeJ8vUej1Ej8/SEsG7xUBobk+LDl2ffUrwaI565 UhBhdl1cQt7q/7XUrLh/TP5AT7J0qmp9St0lFUkwd9MNaumqeg6AaeWktLv68lsCocXfAnM/50Myz C3TWk7kePqQ7EyU+go/JVicyXgGOi+RadZiM6oxwqd5/xx59urBzckcOiuhZGHk5VQDID1vVy0dM3 ttXeI0P11gvNfYQ28802drLCHplVgCVF2mKWrE4ToiE1SNglFa/Yt150BYr1uWocmsIIDkUgepbwE cwMnSJLQ==; 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 1kXOP2-0007zu-8Y; Tue, 27 Oct 2020 12:48:40 +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 AC876300455; Tue, 27 Oct 2020 13:48:34 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id AAE7B203CF3A3; Tue, 27 Oct 2020 13:48:34 +0100 (CET) Date: Tue, 27 Oct 2020 13:48:34 +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: <20201027124834.GL2628@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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201027123056.GE2651@hirez.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 27, 2020 at 01:30:56PM +0100, Peter Zijlstra wrote: > This seems to make it happy. Not quite sure that's the best solution. > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index 3e99dfef8408..81295bc760fe 100644 > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -4411,7 +4405,9 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, > break; > > case LOCK_USED: > - debug_atomic_dec(nr_unused_locks); > + case LOCK_USED_READ: > + if ((hlock_class(this)->usage_mask & (LOCKF_USED|LOCKF_USED_READ)) == new_mask) > + debug_atomic_dec(nr_unused_locks); > break; > > default: This also works, and I think I likes it better.. anyone? diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 3e99dfef8408..e603e86c0227 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -4396,6 +4390,9 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, if (unlikely(hlock_class(this)->usage_mask & new_mask)) goto unlock; + if (!hlock_class(this)->usage_mask) + debug_atomic_dec(nr_unused_locks); + hlock_class(this)->usage_mask |= new_mask; if (new_bit < LOCK_TRACE_STATES) { @@ -4403,19 +4400,10 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, return 0; } - switch (new_bit) { - case 0 ... LOCK_USED-1: + if (new_bit < LOCK_USED) { ret = mark_lock_irq(curr, this, new_bit); if (!ret) return 0; - break; - - case LOCK_USED: - debug_atomic_dec(nr_unused_locks); - break; - - default: - break; } unlock: