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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DDDB0C38159 for ; Wed, 18 Jan 2023 17:43:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231296AbjARRnS (ORCPT ); Wed, 18 Jan 2023 12:43:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231311AbjARRma (ORCPT ); Wed, 18 Jan 2023 12:42:30 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 13B97589A5 for ; Wed, 18 Jan 2023 09:41:42 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B9E1FB81E16 for ; Wed, 18 Jan 2023 17:41:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4EC10C433F0; Wed, 18 Jan 2023 17:41:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674063699; bh=U8QLPf7lyWvHcZUi3WnXi8fbXM4xhuvGnUqsEPVpr+U=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=HTwW1H2WVldVV/MJzRubBzfn1R+hvi+5wdZN+6y1TShC0IiZY1IsmiCrfDs8R7ek8 Zq/W2DHzaZGMwIKV3tzxHgGo0pEcGHsugW3/grz8glzAAOAh1aWOQlXqDL8GhS9ZIA NRaSlrsYHo+Sx8kFrZ1Aq1ZTf7gPAF1vQKcosomiyyN3Ej/MndrGTGIDl01zXWKzw8 8H69VU0rEdlVlbZfNW16fPaDOoWwZoarWbLaU2Ruqwb3q2UZO8vh554B7B/pKKejAq L7figMQaTH4z05diq+LAvHRCpNgDMNywlZkOYvjzFZEY7XjHtojPGHx9EA7Et8rCk7 jLdROjT2h/MCg== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id F27D55C05FB; Wed, 18 Jan 2023 09:41:38 -0800 (PST) Date: Wed, 18 Jan 2023 09:41:38 -0800 From: "Paul E. McKenney" To: Alan Stern Cc: Andrea Parri , Jonas Oberhauser , Peter Zijlstra , will , "boqun.feng" , npiggin , dhowells , "j.alglave" , "luc.maranget" , akiyks , dlustig , joel , urezki , quic_neeraju , frederic , Kernel development list Subject: Re: Internal vs. external barriers (was: Re: Interesting LKMM litmus test) Message-ID: <20230118174138.GB2948950@paulmck-ThinkPad-P17-Gen-1> Reply-To: paulmck@kernel.org References: <20230116190652.GZ2948950@paulmck-ThinkPad-P17-Gen-1> <20230116221357.GA2948950@paulmck-ThinkPad-P17-Gen-1> <20230117151416.GI2948950@paulmck-ThinkPad-P17-Gen-1> <20230117174308.GK2948950@paulmck-ThinkPad-P17-Gen-1> <20230118051704.GX2948950@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 18, 2023 at 11:03:35AM -0500, Alan Stern wrote: > On Tue, Jan 17, 2023 at 09:17:04PM -0800, Paul E. McKenney wrote: > > On Tue, Jan 17, 2023 at 09:15:15PM -0500, Alan Stern wrote: > > > Maybe we don't. Please test the patch below; I think it will do what > > > you want -- and it doesn't rule out nesting. > > > > It works like a champ on manual/kernel/C-srcu*.litmus in the litmus > > repository on github, good show and thank you!!! > > > > I will make more tests, and am checking this against the rest of the > > litmus tests in the repo, but in the meantime would you be willing to > > have me add your Signed-off-by? > > I'll email a real patch submission in the not-too-distant future, > assuming you don't find any problems with the new code. Sounds good! The current state is that last night's testing found a difference only for C-srcu-nest-5.litmus, in which case your version gives the correct answer and mainline is wrong. There were a couple of broken tests, which I fixed and a test involving spin_unlock_wait(), which is at this point perma-broken due to the Linux kernel no longer having such a thing. (Other than its re-introduction into i915, but they define it as a spin_lock_irq() followed by a spin_unlock_irq(), so why worry?) There were also a few timeouts. I intend to run the longer tests overnight. I have not yet come up with a good heuristic to auto-classify automatically generated tests involving SRCU, so I cannot justify making you wait on me to get my act together on that. Thanx, Paul