From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shuah Khan Subject: Re: [RFC v2 00/14] kunit: introduce KUnit, the Linux kernel unit testing framework Date: Thu, 25 Oct 2018 11:40:18 -0600 Message-ID: <4b6eb273-8fe0-75be-dea0-fbbf17a7158c@kernel.org> References: <20181023235750.103146-1-brendanhiggins@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20181023235750.103146-1-brendanhiggins-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: Brendan Higgins , gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, keescook-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, mcgrof-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org Cc: brakmo-b10kYP2dOMg@public.gmane.org, robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, richard-/L3Ra7n9ekc@public.gmane.org, dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, mpe-Gsx/Oe8HsFggBc27wqDAHg@public.gmane.org, Tim.Bird-7U/KSKJipcs@public.gmane.org, linux-um-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, rostedt-nx8X9YLhiw1AfugRpC6u6w@public.gmane.org, kieran.bingham-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org, julia.lawall-L2FTfq7BK8M@public.gmane.org, joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org, linux-kselftest-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, khilman-rdvid1DuHRBWk0Htik3J/w@public.gmane.org, joe-6d6DIl74uiNBDgjK7y7TUQ@public.gmane.org, daniel-/w4YWyX8dFk@public.gmane.org, Shuah Khan , jdike-OPE4K8JWMJJBDgjK7y7TUQ@public.gmane.org, kunit-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org List-Id: dri-devel@lists.freedesktop.org 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. > I am a bit behind on reviewing this patch series. Just a quick note that I will start looking at these early next week. thanks, -- Shuah