From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753665AbdKIQQA (ORCPT ); Thu, 9 Nov 2017 11:16:00 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:48746 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753622AbdKIQP4 (ORCPT ); Thu, 9 Nov 2017 11:15:56 -0500 Subject: Re: [PATCH] locktorture: Fix Oops when reader/writer count is 0 To: paulmck@linux.vnet.ibm.com Cc: Davidlohr Bueso , 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> <20171108174419.GL3624@linux.vnet.ibm.com> From: Jeremy Linton Message-ID: <53f01f03-0af9-a874-d64a-43544bc8895f@arm.com> Date: Thu, 9 Nov 2017 10:15:54 -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: <20171108174419.GL3624@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 Hi, On 11/08/2017 11:44 AM, Paul E. McKenney wrote: > On Wed, Nov 08, 2017 at 10:57:07AM -0600, Jeremy Linton wrote: >> 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 > > Thank you! > >>> 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.. > > Very good! Looking forward to seeing the results. I've been testing it on arm64 machines and it appears to work as expected. Tested-by: Jeremy Linton Thanks, > > 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 >>>> >>> >> >