From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: Re: [PATCH RFC tools/memory-model] Add litmus-test naming scheme Date: Wed, 5 Sep 2018 17:01:17 -0700 Message-ID: <20180906000117.GG4225@linux.vnet.ibm.com> References: <20180525191020.GA5914@linux.vnet.ibm.com> <20180529093050.GB6533@arm.com> <20180529121107.GF3803@linux.vnet.ibm.com> <20180529201713.GD591@arm.com> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20180529201713.GD591@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Will Deacon Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, stern@rowland.harvard.edu, andrea.parri@amarulasolutions.com, peterz@infradead.org, boqun.feng@gmail.com, npiggin@gmail.com, dhowells@redhat.com, j.alglave@ucl.ac.uk, luc.maranget@inria.fr, akiyks@gmail.com, mingo@kernel.org List-Id: linux-arch.vger.kernel.org On Tue, May 29, 2018 at 09:17:13PM +0100, Will Deacon wrote: > On Tue, May 29, 2018 at 05:11:07AM -0700, Paul E. McKenney wrote: > > On Tue, May 29, 2018 at 10:30:50AM +0100, Will Deacon wrote: > > > Hi Paul, > > > > > > On Fri, May 25, 2018 at 12:10:20PM -0700, Paul E. McKenney wrote: > > > > This commit documents the scheme used to generate the names for the > > > > litmus tests. > > > > > > > > Signed-off-by: Paul E. McKenney > > > > --- > > > > README | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- > > > > 1 file changed, 135 insertions(+), 1 deletion(-) > > > > > > Whilst I think documentation like this is extremely important for users, > > > this feels like it's documenting how to drive parts of diy and I'm not > > > convinced that it belongs in the kernel source tree as long as the projects > > > remain separate. > > > > > > Why not contribute this to the herdtools7 documentation, then just reference > > > that from here? That would also be helpful for other people interested in > > > memory models, but perhaps not interested in Linux (assuming such people > > > exist ;). > > > > We would still need at least a pointer from the Linux kernel to that > > documentation, but I am happy either way. We probably need examples of > > the common cases, but probably not a full exposition of all the available > > herd7 edges. > > Completely agreed. > > > Should this be in the herdtools7 documentation, or as added detail > > from a variation on the "diyone7 -bell linux-kernel.bell -show edges" > > command? If the latter, I suppose that the ones coming from the .bell > > file might simply be labelled as such. > > Many of the edges aren't specific to the Linux kernel, so I think they > should be part of the diyone7 documentation. We could then describe only > the additional edges added by the kernel memory model (e.g. "Once") in > the kernel documentation. And there are a -lot- of them, and they are likely to change going forward, both in herd7 and in linux-kernel.bell. How about if I give examples and say where they are from and how to get a list, as in the following --squash commit to be merged with the orginal? Thanx, Paul ------------------------------------------------------------------------ commit e366b8cd832535894c55265c112355c4de9a3247 Author: Paul E. McKenney Date: Wed Sep 5 15:38:00 2018 -0700 squash! EXP tools/memory-model: Add litmus-test naming scheme Signed-off-by: Paul E. McKenney [ paulmck: Apply feedback from Will Deacon. ] diff --git a/tools/memory-model/litmus-tests/README b/tools/memory-model/litmus-tests/README index 08c1116c0314..5ee08f129094 100644 --- a/tools/memory-model/litmus-tests/README +++ b/tools/memory-model/litmus-tests/README @@ -243,56 +243,11 @@ produce the name: Adding the ".litmus" suffix: SB+rfionceonce-poonceonces.litmus +The descriptors that describe connections between consecutive accesses +within the cycle through a given litmus test can be provided by the herd +tool (Rfi, Po, Fre, and so on) or by the linux-kernel.bell file (Once, +Release, Acquire, and so on). -======================= -LITMUS TEST DESCRIPTORS -======================= - -These descriptors cover connections between consecutive accesses within -the cycle through a given litmus test: - -Fre: From-read external. The current process wrote a variable that - the previous process read. Example: The SB (store buffering) test. -Fri: From-read internal. This process read a variable and then - immediately wrote to it. Example: ??? -PodRR: Program-order different variable, read followed by read. - This process read a variable and again read a different variable. - Example: The read-side process in the MP (message-passing) test. -PodRW: Program-order different variable, read followed by write. - This process read a variable and then wrote a different variable. - Example: The LB (load buffering) test. -PodWR: Program-order different variable, write followed by read. - This process wrote a variable and then read a different variable. - Example: The SB (store buffering) test. -PodWW: Program-order different variable, write followed by write. - This process wrote a variable and again wrote a different variable. - Example: The write-side process in the MP (message-passing) test. -PosRR: Program-order same variable, read followed by read. - This process read a variable and again read that same variable. - Example: ??? -PosRW: Program-order same variable, read followed by write. - This process read a variable and then wrote that same variable. - Example: ??? -PosWR: Program-order same variable, write followed by read. - This process wrote a variable and then read that same variable. - Example: ??? -PosWW: Program-order same variable, write followed by write. - This process wrote a variable and again wrote that same variable. - Example: ??? -Rfe: Read-from external. The current process read a variable written - by the previous process. Example: The MP (message passing) test. -Rfi: Read-from internal. The current process wrote a variable and then - immediately read the value back from it. For the purposes - of litmus-test code generation, Rfi acts identically to PosWR. - However, they differ for purposes of naming, and they also result - in different "exists" clauses. - Example: ??? -Wse: Write same external. The current process wrote to a variable that - was also written to by the previous process. Example: ??? -Wsi: Write same internal. The current process wrote to a variable and - then immediately wrote to it again. Example: ??? - -Please note that the above is a partial list. To see the full list of -descriptors, execute the following command: +To see the full list of descriptors, execute the following command: $ diyone7 -bell linux-kernel.bell -show edges From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:57332 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725850AbeIFEd7 (ORCPT ); Thu, 6 Sep 2018 00:33:59 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w85NwglT054730 for ; Wed, 5 Sep 2018 20:01:24 -0400 Received: from e13.ny.us.ibm.com (e13.ny.us.ibm.com [129.33.205.203]) by mx0a-001b2d01.pphosted.com with ESMTP id 2mapvh56ph-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 05 Sep 2018 20:01:24 -0400 Received: from localhost by e13.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 5 Sep 2018 20:01:22 -0400 Date: Wed, 5 Sep 2018 17:01:17 -0700 From: "Paul E. McKenney" Subject: Re: [PATCH RFC tools/memory-model] Add litmus-test naming scheme Reply-To: paulmck@linux.vnet.ibm.com References: <20180525191020.GA5914@linux.vnet.ibm.com> <20180529093050.GB6533@arm.com> <20180529121107.GF3803@linux.vnet.ibm.com> <20180529201713.GD591@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180529201713.GD591@arm.com> Message-ID: <20180906000117.GG4225@linux.vnet.ibm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Will Deacon Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, stern@rowland.harvard.edu, andrea.parri@amarulasolutions.com, peterz@infradead.org, boqun.feng@gmail.com, npiggin@gmail.com, dhowells@redhat.com, j.alglave@ucl.ac.uk, luc.maranget@inria.fr, akiyks@gmail.com, mingo@kernel.org Message-ID: <20180906000117.qJDKcFbqcJzrVdbPsHCyfK0ZJ9NCw7jU6NPjdvQz2tM@z> On Tue, May 29, 2018 at 09:17:13PM +0100, Will Deacon wrote: > On Tue, May 29, 2018 at 05:11:07AM -0700, Paul E. McKenney wrote: > > On Tue, May 29, 2018 at 10:30:50AM +0100, Will Deacon wrote: > > > Hi Paul, > > > > > > On Fri, May 25, 2018 at 12:10:20PM -0700, Paul E. McKenney wrote: > > > > This commit documents the scheme used to generate the names for the > > > > litmus tests. > > > > > > > > Signed-off-by: Paul E. McKenney > > > > --- > > > > README | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- > > > > 1 file changed, 135 insertions(+), 1 deletion(-) > > > > > > Whilst I think documentation like this is extremely important for users, > > > this feels like it's documenting how to drive parts of diy and I'm not > > > convinced that it belongs in the kernel source tree as long as the projects > > > remain separate. > > > > > > Why not contribute this to the herdtools7 documentation, then just reference > > > that from here? That would also be helpful for other people interested in > > > memory models, but perhaps not interested in Linux (assuming such people > > > exist ;). > > > > We would still need at least a pointer from the Linux kernel to that > > documentation, but I am happy either way. We probably need examples of > > the common cases, but probably not a full exposition of all the available > > herd7 edges. > > Completely agreed. > > > Should this be in the herdtools7 documentation, or as added detail > > from a variation on the "diyone7 -bell linux-kernel.bell -show edges" > > command? If the latter, I suppose that the ones coming from the .bell > > file might simply be labelled as such. > > Many of the edges aren't specific to the Linux kernel, so I think they > should be part of the diyone7 documentation. We could then describe only > the additional edges added by the kernel memory model (e.g. "Once") in > the kernel documentation. And there are a -lot- of them, and they are likely to change going forward, both in herd7 and in linux-kernel.bell. How about if I give examples and say where they are from and how to get a list, as in the following --squash commit to be merged with the orginal? Thanx, Paul ------------------------------------------------------------------------ commit e366b8cd832535894c55265c112355c4de9a3247 Author: Paul E. McKenney Date: Wed Sep 5 15:38:00 2018 -0700 squash! EXP tools/memory-model: Add litmus-test naming scheme Signed-off-by: Paul E. McKenney [ paulmck: Apply feedback from Will Deacon. ] diff --git a/tools/memory-model/litmus-tests/README b/tools/memory-model/litmus-tests/README index 08c1116c0314..5ee08f129094 100644 --- a/tools/memory-model/litmus-tests/README +++ b/tools/memory-model/litmus-tests/README @@ -243,56 +243,11 @@ produce the name: Adding the ".litmus" suffix: SB+rfionceonce-poonceonces.litmus +The descriptors that describe connections between consecutive accesses +within the cycle through a given litmus test can be provided by the herd +tool (Rfi, Po, Fre, and so on) or by the linux-kernel.bell file (Once, +Release, Acquire, and so on). -======================= -LITMUS TEST DESCRIPTORS -======================= - -These descriptors cover connections between consecutive accesses within -the cycle through a given litmus test: - -Fre: From-read external. The current process wrote a variable that - the previous process read. Example: The SB (store buffering) test. -Fri: From-read internal. This process read a variable and then - immediately wrote to it. Example: ??? -PodRR: Program-order different variable, read followed by read. - This process read a variable and again read a different variable. - Example: The read-side process in the MP (message-passing) test. -PodRW: Program-order different variable, read followed by write. - This process read a variable and then wrote a different variable. - Example: The LB (load buffering) test. -PodWR: Program-order different variable, write followed by read. - This process wrote a variable and then read a different variable. - Example: The SB (store buffering) test. -PodWW: Program-order different variable, write followed by write. - This process wrote a variable and again wrote a different variable. - Example: The write-side process in the MP (message-passing) test. -PosRR: Program-order same variable, read followed by read. - This process read a variable and again read that same variable. - Example: ??? -PosRW: Program-order same variable, read followed by write. - This process read a variable and then wrote that same variable. - Example: ??? -PosWR: Program-order same variable, write followed by read. - This process wrote a variable and then read that same variable. - Example: ??? -PosWW: Program-order same variable, write followed by write. - This process wrote a variable and again wrote that same variable. - Example: ??? -Rfe: Read-from external. The current process read a variable written - by the previous process. Example: The MP (message passing) test. -Rfi: Read-from internal. The current process wrote a variable and then - immediately read the value back from it. For the purposes - of litmus-test code generation, Rfi acts identically to PosWR. - However, they differ for purposes of naming, and they also result - in different "exists" clauses. - Example: ??? -Wse: Write same external. The current process wrote to a variable that - was also written to by the previous process. Example: ??? -Wsi: Write same internal. The current process wrote to a variable and - then immediately wrote to it again. Example: ??? - -Please note that the above is a partial list. To see the full list of -descriptors, execute the following command: +To see the full list of descriptors, execute the following command: $ diyone7 -bell linux-kernel.bell -show edges