From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: Re: [RFC PATCH] tools/memory-model: Remove (dep ; rfi) from ppo Date: Mon, 4 Mar 2019 08:09:47 -0800 Message-ID: <20190304160947.GB13351@linux.ibm.com> References: <20190222130014.GY32494@hirez.programming.kicks-ass.net> <20190225175517.GK4072@linux.ibm.com> <20190226093009.GS32477@hirez.programming.kicks-ass.net> <20190226104551.GF32534@hirez.programming.kicks-ass.net> <20190226112133.GG32534@hirez.programming.kicks-ass.net> <20190226112521.GH32534@hirez.programming.kicks-ass.net> <20190226113008.GI32534@hirez.programming.kicks-ass.net> <20190226113813.GA14753@zn.tnic> <20190226134906.GG32494@hirez.programming.kicks-ass.net> <8fbdcdc0-1f4e-e268-c183-0d65be3d39c9@gmail.com> Reply-To: paulmck@linux.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <8fbdcdc0-1f4e-e268-c183-0d65be3d39c9@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Akira Yokosawa Cc: Peter Zijlstra , Borislav Petkov , Andrea Parri , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Alan Stern , Will Deacon , Boqun Feng , Nicholas Piggin , David Howells , Jade Alglave , Luc Maranget , Daniel Lustig List-Id: linux-arch.vger.kernel.org On Sun, Mar 03, 2019 at 12:27:12AM +0900, Akira Yokosawa wrote: > Hello Peter, > > On Tue, 26 Feb 2019 14:49:06 +0100, Peter Zijlstra wrote: > > On Tue, Feb 26, 2019 at 12:38:13PM +0100, Borislav Petkov wrote: > >> On Tue, Feb 26, 2019 at 12:30:08PM +0100, Peter Zijlstra wrote: > >>> When I used the argc variant, gcc-8 'works', but with s/argc/1/ it is > >>> still broken. > >> > >> As requested on IRC: > > > > What I asked was if you could get your GCC developer friends to have a > > look at this :-) > > JFYI, there is a bugzilla ticket regarding this behavior of GCC > at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61502, > which started on 13 June 2014 and the latest entry was on > 02 Feb 2019. And that bug was submitted by none other than Peter Sewell, thank you! This bug references https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88775, where someone appears to -want- this sort of optimization. :-/ Thanx, Paul From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:50992 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726924AbfCDQJv (ORCPT ); Mon, 4 Mar 2019 11:09:51 -0500 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x24G5RGw050367 for ; Mon, 4 Mar 2019 11:09:50 -0500 Received: from e11.ny.us.ibm.com (e11.ny.us.ibm.com [129.33.205.201]) by mx0a-001b2d01.pphosted.com with ESMTP id 2r14j1h0sf-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 04 Mar 2019 11:09:50 -0500 Received: from localhost by e11.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 4 Mar 2019 16:09:49 -0000 Date: Mon, 4 Mar 2019 08:09:47 -0800 From: "Paul E. McKenney" Subject: Re: [RFC PATCH] tools/memory-model: Remove (dep ; rfi) from ppo Reply-To: paulmck@linux.ibm.com References: <20190222130014.GY32494@hirez.programming.kicks-ass.net> <20190225175517.GK4072@linux.ibm.com> <20190226093009.GS32477@hirez.programming.kicks-ass.net> <20190226104551.GF32534@hirez.programming.kicks-ass.net> <20190226112133.GG32534@hirez.programming.kicks-ass.net> <20190226112521.GH32534@hirez.programming.kicks-ass.net> <20190226113008.GI32534@hirez.programming.kicks-ass.net> <20190226113813.GA14753@zn.tnic> <20190226134906.GG32494@hirez.programming.kicks-ass.net> <8fbdcdc0-1f4e-e268-c183-0d65be3d39c9@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8fbdcdc0-1f4e-e268-c183-0d65be3d39c9@gmail.com> Message-ID: <20190304160947.GB13351@linux.ibm.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Akira Yokosawa Cc: Peter Zijlstra , Borislav Petkov , Andrea Parri , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Alan Stern , Will Deacon , Boqun Feng , Nicholas Piggin , David Howells , Jade Alglave , Luc Maranget , Daniel Lustig Message-ID: <20190304160947.u_9IfL0iCPxjD2Auaisw9oHVX2b_u_18E2tIn_-kNas@z> On Sun, Mar 03, 2019 at 12:27:12AM +0900, Akira Yokosawa wrote: > Hello Peter, > > On Tue, 26 Feb 2019 14:49:06 +0100, Peter Zijlstra wrote: > > On Tue, Feb 26, 2019 at 12:38:13PM +0100, Borislav Petkov wrote: > >> On Tue, Feb 26, 2019 at 12:30:08PM +0100, Peter Zijlstra wrote: > >>> When I used the argc variant, gcc-8 'works', but with s/argc/1/ it is > >>> still broken. > >> > >> As requested on IRC: > > > > What I asked was if you could get your GCC developer friends to have a > > look at this :-) > > JFYI, there is a bugzilla ticket regarding this behavior of GCC > at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61502, > which started on 13 June 2014 and the latest entry was on > 02 Feb 2019. And that bug was submitted by none other than Peter Sewell, thank you! This bug references https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88775, where someone appears to -want- this sort of optimization. :-/ Thanx, Paul