From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA160C04AB1 for ; Thu, 9 May 2019 21:44:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A3B78217D7 for ; Thu, 9 May 2019 21:44:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726768AbfEIVoR (ORCPT ); Thu, 9 May 2019 17:44:17 -0400 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:45284 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726219AbfEIVoQ (ORCPT ); Thu, 9 May 2019 17:44:16 -0400 Received: from callcc.thunk.org (guestnat-104-133-0-109.corp.google.com [104.133.0.109] (may be forged)) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id x49LgY32008689 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 9 May 2019 17:42:35 -0400 Received: by callcc.thunk.org (Postfix, from userid 15806) id B6256420024; Thu, 9 May 2019 17:42:33 -0400 (EDT) Date: Thu, 9 May 2019 17:42:33 -0400 From: "Theodore Ts'o" To: Frank Rowand Cc: Tim.Bird@sony.com, knut.omang@oracle.com, gregkh@linuxfoundation.org, brendanhiggins@google.com, keescook@google.com, kieran.bingham@ideasonboard.com, mcgrof@kernel.org, robh@kernel.org, sboyd@kernel.org, shuah@kernel.org, devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, kunit-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-um@lists.infradead.org, Alexander.Levin@microsoft.com, amir73il@gmail.com, dan.carpenter@oracle.com, dan.j.williams@intel.com, daniel@ffwll.ch, jdike@addtoit.com, joel@jms.id.au, julia.lawall@lip6.fr, khilman@baylibre.com, logang@deltatee.com, mpe@ellerman.id.au, pmladek@suse.com, richard@nod.at, rientjes@google.com, rostedt@goodmis.org, wfg@linux.intel.com Subject: Re: [PATCH v2 00/17] kunit: introduce KUnit, the Linux kernel unit testing framework Message-ID: <20190509214233.GA20877@mit.edu> Mail-Followup-To: Theodore Ts'o , Frank Rowand , Tim.Bird@sony.com, knut.omang@oracle.com, gregkh@linuxfoundation.org, brendanhiggins@google.com, keescook@google.com, kieran.bingham@ideasonboard.com, mcgrof@kernel.org, robh@kernel.org, sboyd@kernel.org, shuah@kernel.org, devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, kunit-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-nvdimm@lists.01.org, linux-um@lists.infradead.org, Alexander.Levin@microsoft.com, amir73il@gmail.com, dan.carpenter@oracle.com, dan.j.williams@intel.com, daniel@ffwll.ch, jdike@addtoit.com, joel@jms.id.au, julia.lawall@lip6.fr, khilman@baylibre.com, logang@deltatee.com, mpe@ellerman.id.au, pmladek@suse.com, richard@nod.at, rientjes@google.com, rostedt@goodmis.org, wfg@linux.intel.com References: <54940124-50df-16ec-1a32-ad794ee05da7@gmail.com> <20190507080119.GB28121@kroah.com> <20190509015856.GB7031@mit.edu> <580e092f-fa4e-eedc-9e9a-a57dd085f0a6@gmail.com> <20190509032017.GA29703@mit.edu> <7fd35df81c06f6eb319223a22e7b93f29926edb9.camel@oracle.com> <20190509133551.GD29703@mit.edu> <875c546d-9713-bb59-47e4-77a1d2c69a6d@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <875c546d-9713-bb59-47e4-77a1d2c69a6d@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, May 09, 2019 at 11:12:12AM -0700, Frank Rowand wrote: > > "My understanding is that the intent of KUnit is to avoid booting a kernel on > real hardware or in a virtual machine. That seems to be a matter of semantics > to me because isn't invoking a UML Linux just running the Linux kernel in > a different form of virtualization? > > So I do not understand why KUnit is an improvement over kselftest. > > ... > > What am I missing?" One major difference: kselftest requires a userspace environment; it starts systemd, requires a root file system from which you can load modules, etc. Kunit doesn't require a root file system; doesn't require that you start systemd; doesn't allow you to run arbitrary perl, python, bash, etc. scripts. As such, it's much lighter weight than kselftest, and will have much less overhead before you can start running tests. So it's not really the same kind of virtualization. Does this help? - Ted