From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752678AbcDPATa (ORCPT ); Fri, 15 Apr 2016 20:19:30 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:34621 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752054AbcDPAT3 (ORCPT ); Fri, 15 Apr 2016 20:19:29 -0400 Subject: Re: [PATCH] locktorture: make verbose writable and control stats print To: paulmck@linux.vnet.ibm.com References: <1460752091-28023-1-git-send-email-yang.shi@linaro.org> <20160415232613.GC3687@linux.vnet.ibm.com> <57117D1C.3080109@linaro.org> <20160416000930.GD3687@linux.vnet.ibm.com> Cc: linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org From: "Shi, Yang" Message-ID: <5711850F.3000709@linaro.org> Date: Fri, 15 Apr 2016 17:19:27 -0700 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <20160416000930.GD3687@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/15/2016 5:09 PM, Paul E. McKenney wrote: > On Fri, Apr 15, 2016 at 04:45:32PM -0700, Shi, Yang wrote: >> On 4/15/2016 4:26 PM, Paul E. McKenney wrote: >>> On Fri, Apr 15, 2016 at 01:28:11PM -0700, Yang Shi wrote: >>>> When building locktorture test into kernel image, it keeps printing out >>>> stats information even though there is no lock type specified. >>>> >>>> There is already verbose parameter to control print, but it is read-only, >>>> so it can't be changed at runtime. Make verbose read-write and control >>>> stats print. >>>> >>>> Signed-off-by: Yang Shi >>> >>> Interesting change! >>> >>> But just out of curiosity, when you boot with locktorture built in, >>> do you specify the shutdown_secs boot parameter? If so, another >> >> No, just use the default value, which is 0 for shutdown_secs. >> >>> approach would be to shutdown immediately upon detecting an error >>> during initialization. >> >> In my case, it looks there is not error involved. > > You said that there is no lock type specified, but that should mean that > the default ("spin_lock") is chosen. If so, I would expect it to just Yes, spin_lock is chosen by default. > do the test, at least if locktorture.torture_runnable has been set. But, the default value of torture_runnable is 0. And, it is readonly parameter too. This prevents torture from running if it is built into kernel instead of module. Actually, I'm confused why there is not LOCK_TORTURE_TEST_RUNNABLE Kconfig like RCU torture? Thanks, Yang > > Either way, the usual way to make locktorture shut up would be to boot > with locktorture.stat_interval=0. > >>> If not, I would like to know more about your use case. >> >> In my test, I just built locktorture test into kernel instead of a >> module then check how it behaves, no specific purpose. >> >> It sounds like not a normal approach to use it. > > Agreed, I do believe that this is a case of "working as designed". > > Thanx, Paul >