From mboxrd@z Thu Jan 1 00:00:00 1970 From: Akira Yokosawa Subject: Re: [PATCH RFC LKMM 1/7] tools/memory-model: Add extra ordering for locks and remove it for ordinary release/acquire Date: Wed, 5 Sep 2018 23:33:08 +0900 Message-ID: <50f0a7a7-0521-f833-34c3-132ce57dd777@gmail.com> References: <20180904081144.GA4137@andrea> <20180905072151.GA3185@andrea> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180905072151.GA3185@andrea> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Andrea Parri , Alan Stern Cc: Will Deacon , "Paul E. McKenney" , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, mingo@kernel.org, peterz@infradead.org, boqun.feng@gmail.com, npiggin@gmail.com, dhowells@redhat.com, j.alglave@ucl.ac.uk, luc.maranget@inria.fr List-Id: linux-arch.vger.kernel.org On 2018/09/05 09:21:51 +0200, Andrea Parri wrote: > On Tue, Sep 04, 2018 at 03:09:49PM -0400, Alan Stern wrote: >> On Tue, 4 Sep 2018, Andrea Parri wrote: >>> Heh, your confusion might be the reflection of mine... ;-) That was >>> indeed a long and not conclusive discussion (meaning there're pending >>> issues); and I cannot claim to find "arguments" such as: >>> >>> "More than one kernel developer has expressed the opinion that >>> the LKMM should enforce ordering of writes by locking." >>> >>> particularly helpful (I do tend to be convinced by arguments rather >>> than by opinions). In fact, you can take the following as my only >>> current "constructive argument" against the patch [1,2]: >>> >>> THE COMMIT MESSAGE IS RIDICULOUS; PLEASE EXPAND ON IT, AND DO >>> SO BY LEVERAGING BOTH PROS AND CONS OF THE APPLIED CHANGES >> >> Do you have any concrete suggestions (i.e., some actual text) for >> improvements to the patch description? Earlier in your message you >> mentioned that Will's comment: >> >> LKMM offers stronger guarantees that can portably be relied upon >> in the codebase. >> >> would make a good addition. Suitably edited, it could be added to the >> description. I can think of a few other things myself, but I'd like to >> hear your thoughts. Anything else? > > Yes: I do sometimes have the impression that your "rules" for trimming > text in emails/replies are too aggressive... Andrea, by saying "Yes:", do you mean you have something else to be added? I don't think you do, but want to make sure. I'm a bit surprised to see all you wanted was the amendment of the commit log... Akira > > Andrea > > >> >> Alan >> From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f194.google.com ([209.85.215.194]:46487 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727145AbeIETDl (ORCPT ); Wed, 5 Sep 2018 15:03:41 -0400 Subject: Re: [PATCH RFC LKMM 1/7] tools/memory-model: Add extra ordering for locks and remove it for ordinary release/acquire References: <20180904081144.GA4137@andrea> <20180905072151.GA3185@andrea> From: Akira Yokosawa Message-ID: <50f0a7a7-0521-f833-34c3-132ce57dd777@gmail.com> Date: Wed, 5 Sep 2018 23:33:08 +0900 MIME-Version: 1.0 In-Reply-To: <20180905072151.GA3185@andrea> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Andrea Parri , Alan Stern Cc: Will Deacon , "Paul E. McKenney" , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, mingo@kernel.org, peterz@infradead.org, boqun.feng@gmail.com, npiggin@gmail.com, dhowells@redhat.com, j.alglave@ucl.ac.uk, luc.maranget@inria.fr Message-ID: <20180905143308.SM6SlWCe2dvpjfCOAk8w3OJR6BZeCoiZrbIlXgQXsco@z> On 2018/09/05 09:21:51 +0200, Andrea Parri wrote: > On Tue, Sep 04, 2018 at 03:09:49PM -0400, Alan Stern wrote: >> On Tue, 4 Sep 2018, Andrea Parri wrote: >>> Heh, your confusion might be the reflection of mine... ;-) That was >>> indeed a long and not conclusive discussion (meaning there're pending >>> issues); and I cannot claim to find "arguments" such as: >>> >>> "More than one kernel developer has expressed the opinion that >>> the LKMM should enforce ordering of writes by locking." >>> >>> particularly helpful (I do tend to be convinced by arguments rather >>> than by opinions). In fact, you can take the following as my only >>> current "constructive argument" against the patch [1,2]: >>> >>> THE COMMIT MESSAGE IS RIDICULOUS; PLEASE EXPAND ON IT, AND DO >>> SO BY LEVERAGING BOTH PROS AND CONS OF THE APPLIED CHANGES >> >> Do you have any concrete suggestions (i.e., some actual text) for >> improvements to the patch description? Earlier in your message you >> mentioned that Will's comment: >> >> LKMM offers stronger guarantees that can portably be relied upon >> in the codebase. >> >> would make a good addition. Suitably edited, it could be added to the >> description. I can think of a few other things myself, but I'd like to >> hear your thoughts. Anything else? > > Yes: I do sometimes have the impression that your "rules" for trimming > text in emails/replies are too aggressive... Andrea, by saying "Yes:", do you mean you have something else to be added? I don't think you do, but want to make sure. I'm a bit surprised to see all you wanted was the amendment of the commit log... Akira > > Andrea > > >> >> Alan >>