From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752730AbdKHQ5L (ORCPT ); Wed, 8 Nov 2017 11:57:11 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:36022 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752260AbdKHQ5K (ORCPT ); Wed, 8 Nov 2017 11:57:10 -0500 Subject: Re: [PATCH] locktorture: Fix Oops when reader/writer count is 0 To: paulmck@linux.vnet.ibm.com, Davidlohr Bueso Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, mingo@redhat.com, josh@joshtriplett.org References: <20171010155248.11602-1-jeremy.linton@arm.com> <20171107210748.GR3165@worktop.lehotels.local> <20171107221555.GX3624@linux.vnet.ibm.com> <20171108144523.k7ouldzwuawje4wc@linux-n805> <20171108164855.GK3624@linux.vnet.ibm.com> From: Jeremy Linton Message-ID: Date: Wed, 8 Nov 2017 10:57:07 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20171108164855.GK3624@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/08/2017 10:48 AM, Paul E. McKenney wrote: > On Wed, Nov 08, 2017 at 06:45:23AM -0800, Davidlohr Bueso wrote: >> On Tue, 07 Nov 2017, Paul E. McKenney wrote: >> >>> On Tue, Nov 07, 2017 at 10:07:48PM +0100, Peter Zijlstra wrote: >>>> On Tue, Nov 07, 2017 at 02:01:58PM -0600, Jeremy Linton wrote: >>>>> Hi, >>>>> >>>>> On 10/10/2017 10:52 AM, Jeremy Linton wrote: >>>>>> If nwriters_stress=0 is passed to the lock torture test >>>>>> it will panic in: >>>>> >>>>> Ping? >>>>> >>>>> Has anyone had a chance to look at this? >>>> >>>> Helps if you Cc the people actually working on this stuff of course... >>> >>> Thank you for the forward, Peter, I have queued Jeremy's patch for >>> testing and review. >> >> fyi I had proposed the following a while back, which I think is more >> complete than this patch: >> >> https://lkml.org/lkml/2017/5/15/201 >> >> Ah, there's also this (unrelated) fix: >> https://lkml.org/lkml/2017/5/15/203 >> >>> But Jeremy's list of email addresses is what you would expect from >>> looking at MAINTAINERS, so how about the following patch? > > And it looks like Jeremy was not alone -- I was not CCed on either > of those patches, either. > > Dave's patch does look more complete, and it certainly was submitted > first. Let's see if it still applies... And they both do. Yes, avoiding the zero length allocations is probably a good plan, and complaining if both the reader and writer are zero is doesn't hurt either. So, I'm good with that patch too.. Reviewed-by: Jeremy Linton > > Jeremy, could you please test Dave's patches and make sure that they > work for you? That way I can apply your Tested-by. Dave, any objection > to my adding Jeremy's Reported-by to your /201 patch? I will give it a spin.. > > Thanx, Paul > >>> ------------------------------------------------------------------------ >>> >>> commit 58322063498c8f5a3cc88f95bee237a0ce81f70a >>> Author: Paul E. McKenney >>> Date: Tue Nov 7 14:10:03 2017 -0800 >>> >>> torture: Place all torture-test modules in one MAINTAINERS group >>> >>> There is some confusion about where patches to kernel/torture.c >>> and kernel/locking/locktorture.c should be sent. This commit >>> therefore updates MAINTAINERS appropriately. >>> >>> Reported-by: Peter Zijlstra >>> Signed-off-by: Paul E. McKenney >>> >>> diff --git a/MAINTAINERS b/MAINTAINERS >>> index 2d3d750b19c0..eab868adedc6 100644 >>> --- a/MAINTAINERS >>> +++ b/MAINTAINERS >>> @@ -8091,6 +8091,7 @@ F: arch/*/include/asm/rwsem.h >>> F: include/linux/seqlock.h >>> F: lib/locking*.[ch] >>> F: kernel/locking/ >>> +X: kernel/locking/locktorture.c >>> >>> LOGICAL DISK MANAGER SUPPORT (LDM, Windows 2000/XP/Vista Dynamic Disks) >>> M: "Richard Russon (FlatCap)" >>> @@ -11318,15 +11319,6 @@ L: linux-wireless@vger.kernel.org >>> S: Orphan >>> F: drivers/net/wireless/ray* >>> >>> -RCUTORTURE MODULE >>> -M: Josh Triplett >>> -M: "Paul E. McKenney" >>> -L: linux-kernel@vger.kernel.org >>> -S: Supported >>> -T: git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git >>> -F: Documentation/RCU/torture.txt >>> -F: kernel/rcu/rcutorture.c >>> - >>> RCUTORTURE TEST FRAMEWORK >>> M: "Paul E. McKenney" >>> M: Josh Triplett >>> @@ -13558,6 +13550,18 @@ L: platform-driver-x86@vger.kernel.org >>> S: Maintained >>> F: drivers/platform/x86/topstar-laptop.c >>> >>> +TORTURE-TEST MODULES >>> +M: Davidlohr Bueso >>> +M: "Paul E. McKenney" >>> +M: Josh Triplett >>> +L: linux-kernel@vger.kernel.org >>> +S: Supported >>> +T: git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git >>> +F: Documentation/RCU/torture.txt >>> +F: kernel/torture.c >>> +F: kernel/rcu/rcutorture.c >>> +F: kernel/locking/locktorture.c >> >> Sure, if you think this is the best way to go, I have no problem. >> >> Thanks, >> Davidlohr >> >