From mboxrd@z Thu Jan 1 00:00:00 1970 From: Randy Dunlap Subject: Re: [Ksummit-discuss] [MAINTAINERS SUMMIT] & [TECH TOPIC] Improve regression tracking Date: Wed, 2 Aug 2017 11:23:59 -0700 Message-ID: <8a863ffe-84b5-e65a-988f-b5eda326181d@infradead.org> References: <576cea07-770a-4864-c3f5-0832ff211e94@leemhuis.info> <20170703123025.7479702e@gandalf.local.home> <20170705084528.67499f8c@gandalf.local.home> <4080ecc7-1aa8-2940-f230-1b79d656cdb4@redhat.com> <20170705092757.63dc2328@gandalf.local.home> <20170705140607.GA30187@kroah.com> <20170705112707.54d7f345@gandalf.local.home> <20170705130200.7c653f61@gandalf.local.home> <87zibkzgve.fsf@xmission.com> <87lgn1nac8.fsf@xmission.com> <61093c3f-6ad0-c033-a524-f2624f8d55ba@osg.samsung.com> <87r2wtluc1.fsf@xmission.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <87r2wtluc1.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> Content-Language: en-US Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Eric W. Biederman" , Shuah Khan Cc: Steven Rostedt , Guenter Roeck , ksummit-discuss-cunTk1MwBs98uUxBSJOaYoYkZiVZrdSR2LY78lusg7I@public.gmane.org, Carlos O'Donell , Thorsten Leemhuis , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Shuah Khan List-Id: linux-api@vger.kernel.org On 08/02/2017 11:04 AM, Eric W. Biederman wrote: > Shuah Khan writes: > >> On 08/02/2017 11:33 AM, Eric W. Biederman wrote: >>> Shuah Khan writes: >>> >>>> On 07/31/2017 10:54 AM, Eric W. Biederman wrote: >>>>> Steven Rostedt writes: >>>>> >>>>>> On Wed, 5 Jul 2017 09:48:31 -0700 >>>>>> Guenter Roeck wrote: >>>>>> >>>>>>> On 07/05/2017 08:27 AM, Steven Rostedt wrote: >>>>>>>> On Wed, 5 Jul 2017 08:16:33 -0700 >>>>>>>> Guenter Roeck wrote: >>>>>>> [ ... ] >>>>>>>>> >>>>>>>>> If we start shaming people for not providing unit tests, all we'll accomplish is >>>>>>>>> that people will stop providing bug fixes. >>>>>>>> >>>>>>>> I need to be clearer on this. What I meant was, if there's a bug >>>>>>>> where someone has a test that easily reproduces the bug, then if >>>>>>>> there's not a test added to selftests for said bug, then we should >>>>>>>> shame those into doing so. >>>>>>>> >>>>>>> >>>>>>> I don't think that public shaming of kernel developers is going to work >>>>>>> any better than public shaming of children or teenagers. >>>>>>> >>>>>>> Maybe a friendlier approach would be more useful ? >>>>>> >>>>>> I'm a friendly shamer ;-) >>>>>> >>>>>>> >>>>>>> If a test to reproduce a problem exists, it might be more beneficial to suggest >>>>>>> to the patch submitter that it would be great if that test would be submitted >>>>>>> as unit test instead of shaming that person for not doing so. Acknowledging and >>>>>>> praising kselftest submissions might help more than shaming for non-submissions. >>>>>>> >>>>>>>> A bug that is found by inspection or hard to reproduce test cases are >>>>>>>> not applicable, as they don't have tests that can show a regression. >>>>>>>> >>>>>>> >>>>>>> My concern would be that once the shaming starts, it won't stop. >>>>>> >>>>>> I think this is a communication issue. My word for "shaming" was to >>>>>> call out a developer for not submitting a test. It wasn't about making >>>>>> fun of them, or anything like that. I was only making a point >>>>>> about how to teach people that they need to be more aware of the >>>>>> testing infrastructure. Not about actually demeaning people. >>>>>> >>>>>> Lets take a hypothetical sample. Say someone posted a bug report with >>>>>> an associated reproducer for it. The developer then runs the reproducer >>>>>> sees the bug, makes a fix and sends it to Linus and stable. Now the >>>>>> developer forgets this and continues on their merry way. Along comes >>>>>> someone like myself and sees a reproducing test case for a bug, but >>>>>> sees no test added to kselftests. I would send an email along the lines >>>>>> of "Hi, I noticed that there was a reproducer for this bug you fixed. >>>>>> How come there was no test added to the kselftests to make sure it >>>>>> doesn't appear again?" There, I "shamed" them ;-) >>>>> >>>>> I just want to point out that kselftests are hard to build and run. >>>>> >>>>> As I was looking at another issue I found a bug in one of the tests. It >>>>> had defined a constant wrong. I have a patch. It took me a week of >>>>> poking at the kselftest code and trying one thing or another (between >>>>> working on other things) before I could figure out which combination of >>>>> things would let the test build and run. >>>>> >>>>> Until kselftests get easier to run I don't think they are something we >>>>> want to push to hard. >>>>> >>>> >>>> I would say it is easy to run ksefltests - "make kseflttest" from the >>>> main Makefile does this for you. You can also run individual tests: >>> >>> On 4.13-rc1 That doesn't work. >>> >>> $ make O=$PWD-build -j8 kselftests >>> make[1]: Entering directory 'linux-build' >>> make[1]: *** No rule to make target 'kselftests'. Stop. >>> make[1]: Leaving directory 'linux-build' >>> Makefile:145: recipe for target 'sub-make' failed >>> make: *** [sub-make] Error 2 >> >> It is "make kselftest" > > If I include the standard O= to keep my source tree pristine > it still fails. Which is a practical issue. Especially because > that "make kselftest" needs to be followed by I think "make mrproper" > to get back to my normal development workflow. I mentioned that problem/issue about 6 months ago. I too would like to use O=builddir, but it is ignored. > I don't remember exactly what the issue was but I could not get: > tools/testing/selftests/x86/mpx-mini-test.c > tools/testing/selftests/x86/protection_keys.c > > to build let alone run when I did "make kselftest" > >>> And why I have to use some esoteric command and not just the >>> traditional "make path/to/test/output" to run an individual >>> test is beyond me. >>> >> >> make kselftest from top level Makefile is a way to run all the tests. >> As I mentioned in my previous email >> >> "You can also run individual tests: >> >> "make -C tools/testing/selftests/sync" for example to run sync tests. >> >> or you can also run: >> >> make -C tools/testing/selftests/ run_tests > > As I said complicated. That is definitely not the ordinary way of > building things in the kernel tree. > > Given that some of those other tests take a little while to run, running > individual tests is actually quite important during development. -- ~Randy