From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752861AbbC2Qrz (ORCPT ); Sun, 29 Mar 2015 12:47:55 -0400 Received: from a.ns.miles-group.at ([95.130.255.143]:65277 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752757AbbC2Qrx (ORCPT ); Sun, 29 Mar 2015 12:47:53 -0400 Message-ID: <55182CB1.2090002@nod.at> Date: Sun, 29 Mar 2015 18:47:45 +0200 From: Richard Weinberger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Hajime Tazaki CC: pooka@iki.fi, linux-arch@vger.kernel.org, arnd@arndb.de, corbet@lwn.net, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [RFC PATCH 00/11] an introduction of library operating system for Linux (LibOS) References: <1427202642-1716-1-git-send-email-tazaki@sfc.wide.ad.jp> <551164ED.5000907@nod.at> <55117565.6080002@nod.at> <55118277.5070909@nod.at> <55133BAF.30301@nod.at> In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 29.03.2015 um 17:36 schrieb Hajime Tazaki: > > > At Sat, 28 Mar 2015 22:17:40 +0100, > Richard Weinberger wrote: > >>> Continuous testing is paramount. Running the kernel as >>> a lib provides an unparalleled method for testing most of >>> the kernel. It will improve testing capabilities >>> dramatically, >>> and on the flipside it will keep the libos working. >>> Everyone wins. >> >> If it can be done cheap, yes. But our in-kernel tests improved over the years a lot. >> Now have lockdep, KASan, kmemleak, etc. to find *real-world* issues and the need for stubbed testing >> decreases. > > let me take the same example I raised. > > - Patchwork [net-next] xfrm6: Fix a offset value for network header in _decode_session6 > http://patchwork.ozlabs.org/patch/436351/ > > without stubbed testing (I didn't know this term btw), we > can't decrease untested paths of the code. > > the above bug is for Mobile IPv6, which not so many people > are using though, but it's certainly a regression for a > person. > > testing framework with libos is based on a network > simulator, with a slight decreased realism (but it can > detect a real bug !), but provides a lightweight multi-node > testing framework with a single test scenario script to > control over the nodes. > > it doesn't require heavyweight machines nor complex cabling > for a bunch of tests. > > even a framework is not cheap, I would use such a testing > tool IF we can improve the code. plus (as you may know), it > certainly reduces the maintenance effort once it's automated. Don't get me wrong, I totally agree that this kind of testing is good. But as I said before we have to keep the maintenance burden in mind. Let's wait a bit what Arnd says. He is the Linux arch maintainer. Thanks, //richard