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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 C6F17C3F2D2 for ; Fri, 28 Feb 2020 14:37:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9BA2D2469F for ; Fri, 28 Feb 2020 14:37:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582900673; bh=XFQsfx12dItcvA+iLjesdCvT7+o8NO3ArdHt415SfWM=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=1n4rMMvEtUoUidglopIPdf2eLTN5+/KtpN3IznlutY2uWcHjnEFiaJiqdQeR+1z/j mqEHvVFXmX6ihEz2wTrlJ9gDTYDcIN9B2zdjiNGNCo2G3e1OicgQl+TSJAC6qI3p4v uCY4VgDka8JsY1DzKmJez3+C1lk0eKbmmRMRMgt4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727018AbgB1Ohw (ORCPT ); Fri, 28 Feb 2020 09:37:52 -0500 Received: from mail.kernel.org ([198.145.29.99]:36576 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726561AbgB1Ohw (ORCPT ); Fri, 28 Feb 2020 09:37:52 -0500 Received: from paulmck-ThinkPad-P72.home (199-192-87-166.static.wiline.com [199.192.87.166]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 749682468E; Fri, 28 Feb 2020 14:37:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582900671; bh=XFQsfx12dItcvA+iLjesdCvT7+o8NO3ArdHt415SfWM=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=Jve5DvL8xVAVQPVOWdn8gjP7CetTc6P8sza+3lCwxn9DlPv97bm0I9+U0+r2pZ6d3 FGIe9aPjqrmsHQ4b6hOLsJxPVI69I+m5yl5IWiDmKTeoK7SVZZ02qaPaHrqba3Jabd MhqtaVrYhc4oX6xrdUH5x4QRepybThWTEB4UCgV4= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 1A5DB35226D1; Fri, 28 Feb 2020 06:37:51 -0800 (PST) Date: Fri, 28 Feb 2020 06:37:51 -0800 From: "Paul E. McKenney" To: Joel Fernandes Cc: madhuparnabhowmik10@gmail.com, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, linux-kernel@vger.kernel.org, Amol Grover Subject: Re: [PATCH] Default enable RCU list lockdep debugging with PROVE_RCU Message-ID: <20200228143751.GJ2935@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20200228092451.10455-1-madhuparnabhowmik10@gmail.com> <20200228142122.GA97131@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200228142122.GA97131@google.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 28, 2020 at 09:21:22AM -0500, Joel Fernandes wrote: > On Fri, Feb 28, 2020 at 02:54:51PM +0530, madhuparnabhowmik10@gmail.com wrote: > > From: Madhuparna Bhowmik > > > > This patch default enables CONFIG_PROVE_RCU_LIST option with > > CONFIG_PROVE_RCU for RCU list lockdep debugging. > > > > With this change, RCU list lockdep debugging will be default > > enabled in CONFIG_PROVE_RCU=y kernels. > > > > Most of the RCU users (in core kernel/, drivers/, and net/ > > subsystem) have already been modified to include lockdep > > expressions hence RCU list debugging can be enabled by > > default. > > > > However, there are still chances of enountering > > false-positive lockdep splats because not everything is converted, > > in case RCU list primitives are used in non-RCU read-side critical > > section but under the protection of a lock. It would be okay to > > have a few false-positives, as long as bugs are identified, since this > > patch only affects debugging kernels. > > > > Co-developed-by: Amol Grover > > Signed-off-by: Amol Grover > > Signed-off-by: Madhuparna Bhowmik > > Acked-by: Joel Fernandes (Google) Queued, thank you both! Thanx, Paul > thanks, > > - Joel > > > --- > > kernel/rcu/Kconfig.debug | 11 +++-------- > > 1 file changed, 3 insertions(+), 8 deletions(-) > > > > diff --git a/kernel/rcu/Kconfig.debug b/kernel/rcu/Kconfig.debug > > index 4aa02eee8f6c..ec4bb6c09048 100644 > > --- a/kernel/rcu/Kconfig.debug > > +++ b/kernel/rcu/Kconfig.debug > > @@ -9,15 +9,10 @@ config PROVE_RCU > > def_bool PROVE_LOCKING > > > > config PROVE_RCU_LIST > > - bool "RCU list lockdep debugging" > > - depends on PROVE_RCU && RCU_EXPERT > > - default n > > + def_bool PROVE_RCU > > help > > - Enable RCU lockdep checking for list usages. By default it is > > - turned off since there are several list RCU users that still > > - need to be converted to pass a lockdep expression. To prevent > > - false-positive splats, we keep it default disabled but once all > > - users are converted, we can remove this config option. > > + Enable RCU lockdep checking for list usages. It is default > > + enabled with CONFIG_PROVE_RCU. > > > > config TORTURE_TEST > > tristate > > -- > > 2.17.1 > >