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=-11.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,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 56B25C4363A for ; Mon, 5 Oct 2020 16:52:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 106F42085B for ; Mon, 5 Oct 2020 16:52:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601916745; bh=vDaSw7or0+IopPu+t3KiIUtfzVibfMKUvXPz8Qzewgw=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=dyXhVOh26SQcu1+bTJMztrENsPMjt6vQZTNiRAxP05jhJSe5k76b4Y96G+yswcAfw MniANRZY1LwWtS83nv/XfhrorLQxepc4Lxj9TH3/df0Vo1DLbTFTjqWWF9ZpilXcD1 XoOpK8mmdgPv6WwNH8gxpKDWhNdf7fO82SJ1kJZs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726133AbgJEQwY (ORCPT ); Mon, 5 Oct 2020 12:52:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:59598 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725940AbgJEQwY (ORCPT ); Mon, 5 Oct 2020 12:52:24 -0400 Received: from paulmck-ThinkPad-P72.home (50-39-104-11.bvtn.or.frontiernet.net [50.39.104.11]) (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 89ABF207BC; Mon, 5 Oct 2020 16:52:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601916743; bh=vDaSw7or0+IopPu+t3KiIUtfzVibfMKUvXPz8Qzewgw=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=cFt0jE2h24BB/WingHvOzg40dIUJExT4SajS+jIpZ3qIpmADC96pOT7ud7MDEQvRG BMjNUS5RrPVoYfcFutNVt/OQDAI1jWU8W0Dnm/FJtZgujmymWuwZ9QJp/aiTx1Qlm2 eBeJ9jCGksQ78ID782P3qqc40zIjTUrVQQAOLbCk= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 512C8352301E; Mon, 5 Oct 2020 09:52:23 -0700 (PDT) Date: Mon, 5 Oct 2020 09:52:23 -0700 From: "Paul E. McKenney" To: Alan Stern Cc: Luc Maranget , Akira Yokosawa , parri.andrea@gmail.com, will@kernel.org, peterz@infradead.org, boqun.feng@gmail.com, npiggin@gmail.com, dhowells@redhat.com, j.alglave@ucl.ac.uk, dlustig@nvidia.com, joel@joelfernandes.org, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: Bug in herd7 [Was: Re: Litmus test for question from Al Viro] Message-ID: <20201005165223.GB29330@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20201001045116.GA5014@paulmck-ThinkPad-P72> <20201001161529.GA251468@rowland.harvard.edu> <20201001213048.GF29330@paulmck-ThinkPad-P72> <20201003132212.GB318272@rowland.harvard.edu> <045c643f-6a70-dfdf-2b1e-f369a667f709@gmail.com> <20201003171338.GA323226@rowland.harvard.edu> <20201005151557.4bcxumreoekgwmsa@yquem.inria.fr> <20201005155310.GH376584@rowland.harvard.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201005155310.GH376584@rowland.harvard.edu> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Mon, Oct 05, 2020 at 11:53:10AM -0400, Alan Stern wrote: > On Mon, Oct 05, 2020 at 05:15:57PM +0200, Luc Maranget wrote: > > > On Sun, Oct 04, 2020 at 12:16:31AM +0900, Akira Yokosawa wrote: > > > > > P1(int *x, int *y) > > > > > { > > > > > WRITE_ONCE(*x, READ_ONCE(*y)); > > > > > > > > Looks like this one-liner doesn't provide data-dependency of y -> x on herd7. > > > > > > You're right. This is definitely a bug in herd7. > > > > > > Luc, were you aware of this? > > > > Hi Alan, > > > > No I was not aware of it. Now I am, the bug is normally fixed in the master branch of herd git deposit. > > > > > > Thanks for the report. > > I tested the new commit -- it does indeed fix the problem. Beat me to it, very good! ;-) But were you using the crypto-control-data litmus test? That one still gets me Sometimes: $ herd7 -version 7.56+02~dev, Rev: 0f3f8188a326d5816a82fb9970fcd209a2678859 $ herd7 -conf linux-kernel.cfg ~/paper/scalability/LWNLinuxMM/litmus/manual/kernel/crypto-control-data.litmus Test crypto-control-data Allowed States 2 0:r1=0; 0:r1=1; Ok Witnesses Positive: 1 Negative: 4 Condition exists (0:r1=1) Observation crypto-control-data Sometimes 1 4 Time crypto-control-data 0.00 Hash=10898119bac87e11f31dc22bbb7efe17 Or did I mess something up? Thanx, Paul