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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 CA3CEECDFB1 for ; Tue, 17 Jul 2018 09:25:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E3082086E for ; Tue, 17 Jul 2018 09:25:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8E3082086E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com 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 S1729840AbeGQJ5b (ORCPT ); Tue, 17 Jul 2018 05:57:31 -0400 Received: from terminus.zytor.com ([198.137.202.136]:58841 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728883AbeGQJ5a (ORCPT ); Tue, 17 Jul 2018 05:57:30 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w6H9PSRr1461887 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 17 Jul 2018 02:25:28 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w6H9PRlt1461884; Tue, 17 Jul 2018 02:25:27 -0700 Date: Tue, 17 Jul 2018 02:25:27 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: "tip-bot for Paul E. McKenney" Message-ID: Cc: torvalds@linux-foundation.org, stern@rowland.harvard.edu, mingo@kernel.org, tglx@linutronix.de, hpa@zytor.com, paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, peterz@infradead.org, andrea.parri@amarulasolutions.com Reply-To: hpa@zytor.com, paulmck@linux.vnet.ibm.com, stern@rowland.harvard.edu, mingo@kernel.org, torvalds@linux-foundation.org, tglx@linutronix.de, andrea.parri@amarulasolutions.com, peterz@infradead.org, linux-kernel@vger.kernel.org In-Reply-To: <20180716180605.16115-1-paulmck@linux.vnet.ibm.com> References: <20180716180605.16115-1-paulmck@linux.vnet.ibm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:locking/core] tools/memory-model: Add litmus test for full multicopy atomicity Git-Commit-ID: b464818978d45cd4d78c8f13207891142c68bea9 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: b464818978d45cd4d78c8f13207891142c68bea9 Gitweb: https://git.kernel.org/tip/b464818978d45cd4d78c8f13207891142c68bea9 Author: Paul E. McKenney AuthorDate: Mon, 16 Jul 2018 11:05:52 -0700 Committer: Ingo Molnar CommitDate: Tue, 17 Jul 2018 09:29:29 +0200 tools/memory-model: Add litmus test for full multicopy atomicity This commit adds a litmus test suggested by Alan Stern that is forbidden on fully multicopy atomic systems, but allowed on other-multicopy and on non-multicopy atomic systems. For reference, s390 is fully multicopy atomic, x86 and ARMv8 are other-multicopy atomic, and ARMv7 and powerpc are non-multicopy atomic. Suggested-by: Alan Stern Signed-off-by: Paul E. McKenney Acked-by: Alan Stern Acked-by: Andrea Parri Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: akiyks@gmail.com Cc: boqun.feng@gmail.com Cc: dhowells@redhat.com Cc: j.alglave@ucl.ac.uk Cc: linux-arch@vger.kernel.org Cc: luc.maranget@inria.fr Cc: npiggin@gmail.com Cc: parri.andrea@gmail.com Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/20180716180605.16115-1-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- tools/memory-model/litmus-tests/README | 9 ++++++ .../litmus-tests/SB+rfionceonce-poonceonces.litmus | 32 ++++++++++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/tools/memory-model/litmus-tests/README b/tools/memory-model/litmus-tests/README index 17eb9a8c222d..00140aaf58b7 100644 --- a/tools/memory-model/litmus-tests/README +++ b/tools/memory-model/litmus-tests/README @@ -111,6 +111,15 @@ SB+mbonceonces.litmus SB+poonceonces.litmus As above, but without the smp_mb() invocations. +SB+rfionceonce-poonceonces.litmus + This litmus test demonstrates that LKMM is not fully multicopy + atomic. (Neither is it other multicopy atomic.) This litmus test + also demonstrates the "locations" debugging aid, which designates + additional registers and locations to be printed out in the dump + of final states in the herd7 output. Without the "locations" + statement, only those registers and locations mentioned in the + "exists" clause will be printed. + S+poonceonces.litmus As below, but without the smp_wmb() and acquire load. diff --git a/tools/memory-model/litmus-tests/SB+rfionceonce-poonceonces.litmus b/tools/memory-model/litmus-tests/SB+rfionceonce-poonceonces.litmus new file mode 100644 index 000000000000..04a16603660b --- /dev/null +++ b/tools/memory-model/litmus-tests/SB+rfionceonce-poonceonces.litmus @@ -0,0 +1,32 @@ +C SB+rfionceonce-poonceonces + +(* + * Result: Sometimes + * + * This litmus test demonstrates that LKMM is not fully multicopy atomic. + *) + +{} + +P0(int *x, int *y) +{ + int r1; + int r2; + + WRITE_ONCE(*x, 1); + r1 = READ_ONCE(*x); + r2 = READ_ONCE(*y); +} + +P1(int *x, int *y) +{ + int r3; + int r4; + + WRITE_ONCE(*y, 1); + r3 = READ_ONCE(*y); + r4 = READ_ONCE(*x); +} + +locations [0:r1; 1:r3; x; y] (* Debug aid: Print things not in "exists". *) +exists (0:r2=0 /\ 1:r4=0)