From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id F151D21188C47 for ; Fri, 2 Nov 2018 11:23:55 -0700 (PDT) Subject: Re: [RFC v2 00/14] kunit: introduce KUnit, the Linux kernel unit testing framework References: <20181023235750.103146-1-brendanhiggins@google.com> From: Shuah Khan Message-ID: Date: Fri, 2 Nov 2018 12:23:53 -0600 MIME-Version: 1.0 In-Reply-To: <20181023235750.103146-1-brendanhiggins@google.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Brendan Higgins , gregkh@linuxfoundation.org, keescook@google.com, mcgrof@kernel.org Cc: brakmo@fb.com, robh@kernel.org, richard@nod.at, dri-devel@lists.freedesktop.org, linux-nvdimm@lists.01.org, mpe@ellerman.id.au, Tim.Bird@sony.com, linux-um@lists.infradead.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, kieran.bingham@ideasonboard.com, julia.lawall@lip6.fr, joel@jms.id.au, linux-kselftest@vger.kernel.org, khilman@baylibre.com, joe@perches.com, daniel@ffwll.ch, Shuah Khan , jdike@addtoit.com, kunit-dev@googlegroups.com List-ID: Hi Brendan, On 10/23/2018 05:57 PM, Brendan Higgins wrote: > This patch set proposes KUnit, a lightweight unit testing and mocking > framework for the Linux kernel. > > Unlike Autotest and kselftest, KUnit is a true unit testing framework; > it does not require installing the kernel on a test machine or in a VM > and does not require tests to be written in userspace running on a host > kernel. Additionally, KUnit is fast: From invocation to completion KUnit > can run several dozen tests in under a second. Currently, the entire > KUnit test suite for KUnit runs in under a second from the initial > invocation (build time excluded). > > KUnit is heavily inspired by JUnit, Python's unittest.mock, and > Googletest/Googlemock for C++. KUnit provides facilities for defining > unit test cases, grouping related test cases into test suites, providing > common infrastructure for running tests, mocking, spying, and much more. > > ## What's so special about unit testing? > > A unit test is supposed to test a single unit of code in isolation, > hence the name. There should be no dependencies outside the control of > the test; this means no external dependencies, which makes tests orders > of magnitudes faster. Likewise, since there are no external dependencies, > there are no hoops to jump through to run the tests. Additionally, this > makes unit tests deterministic: a failing unit test always indicates a > problem. Finally, because unit tests necessarily have finer granularity, > they are able to test all code paths easily solving the classic problem > of difficulty in exercising error handling code. > > ## Is KUnit trying to replace other testing frameworks for the kernel? > > No. Most existing tests for the Linux kernel are end-to-end tests, which > have their place. A well tested system has lots of unit tests, a > reasonable number of integration tests, and some end-to-end tests. KUnit > is just trying to address the unit test space which is currently not > being addressed. > > ## More information on KUnit > > There is a bunch of documentation near the end of this patch set that > describes how to use KUnit and best practices for writing unit tests. > For convenience I am hosting the compiled docs here: > https://google.github.io/kunit-docs/third_party/kernel/docs/ > > ## Changes Since Last Version > > - Updated patchset to apply cleanly on 4.19. > - Stripped down patchset to focus on just the core features (I dropped > mocking, spying, and the MMIO stuff for now; you can find these > patches here: https://kunit-review.googlesource.com/c/linux/+/1132), > as suggested by Rob. > - Cleaned up some of the commit messages and tweaked commit order a > bit based on suggestions. > Framework looks good. I think it would be helpful to include a real test in the patch series to get a feel for how effective it is. On one hand, KUnit stands on its own as its own and maybe it should be placed in under tools/testing/KUnit, however I am wondering would it be beneficial for the framework to under selftests. I am a bit concerned about the number of test framework we have at the moment and are we running the risk of fragmenting the landscape. I am concerned if this would lead to developer confusion as to where to add tests. That being said, I don't have a strong opinion one way or the other. btw I started playing with kunit following the instructions and ran into problems: ./tools/testing/kunit/kunit.py usage: kunit.py [-h] {run,new} ... Helps writing and running KUnit tests. positional arguments: {run,new} run Runs KUnit tests. new Prints out boilerplate for writing new tests. optional arguments: -h, --help show this help message and exit ./tools/testing/kunit/kunit.py run Regenerating .config ... ERROR:root:Provided Kconfig is not contained in validated .config! thanks, -- Shuah _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm