Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753285AbcC1Nsh (ORCPT ); Mon, 28 Mar 2016 09:48:37 -0400 Received: from mail-wm0-f51.google.com ([74.125.82.51]:37910 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751212AbcC1Nsf convert rfc822-to-8bit (ORCPT ); Mon, 28 Mar 2016 09:48:35 -0400 MIME-Version: 1.0 In-Reply-To: <56F92196.6040604@collabora.co.uk> References: <1457537342-678-1-git-send-email-emilio.lopez@collabora.co.uk> <1457537342-678-2-git-send-email-emilio.lopez@collabora.co.uk> <56F92196.6040604@collabora.co.uk> Date: Mon, 28 Mar 2016 14:48:33 +0100 Message-ID: Subject: Re: [RFC PATCH v1 1/9] selftest: sync: basic tests for sw_sync framework From: Emil Velikov To: =?UTF-8?Q?Emilio_L=C3=B3pez?= Cc: Shuah Khan , devel@driverdev.osuosl.org, Daniel Stone , Daniel Vetter , =?UTF-8?B?QXJ2ZSBIasO4bm5ldsOlZw==?= , "Linux-Kernel@Vger. Kernel. Org" , ML dri-devel , Riley Andrews , linux-kselftest@vger.kernel.org, Gustavo Padovan , John Harrison Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2281 Lines: 56 On 28 March 2016 at 13:20, Emilio López wrote: > Hi, > > El 28/03/16 a las 08:56, Emil Velikov escribió: >> >> Hi Emilio, >> >> On 9 March 2016 at 15:28, Emilio López >> wrote: >>> >>> These tests are based on the libsync test suite from Android. >>> This commit lays the ground for future tests, as well as includes >>> tests for a variety of basic allocation commands. >>> >>> Signed-off-by: Gustavo Padovan >>> Signed-off-by: Emilio López >>> --- >>> >> >>> tools/testing/selftests/sync/sync.h | 119 ++++++++++++++++++ >> >> Admittedly I know nothing about the kernel selftests although copying >> the UAPI header, seems to defeat the purpose of this exercise. >> Shouldn't one reuse the existing header ? It would even cause issues >> as the interface gets updated (iirc Gustavo changed the ioctl numbers >> and/or header name with latter series). > > > The problem is that one cannot use the system header without having built > and installed the kernel first, which is rather problematic for eg. > crosscompiling or virtualization. I discussed this with Gustavo and we > agreed that the best way forward would be to copy the interfaces, as > suggested by kernelnewbies' wiki[0]: > In the case of using a system header one can just `make headers_install' without building the kernel, as mentioned in the very same page ;-) Although I wasn't thinking that one should be using the header already available in tree. After all this series is not supposed to land before Gustavo's work, is it ? >From a quick skim though the selftests, I cannot see cases where UAPI headers are copied/duplicated. > """ > The correct way to address this problem is to isolate the specific > interfaces that you need, e.g. a single header file that is patched in a new > kernel providing the ioctl numbers for a character device used by your > program. In your own program, add a copy of that source file, with a notice > that it should be kept in sync with new kernel versions. > """ My understanding of the article is that it refers to building user space programs that do _not_ live in the same tree as the kernel. Am I missing something ? Regards, Emil