From mboxrd@z Thu Jan 1 00:00:00 1970 X-GM-THRID: 6249137798348013568 X-Received: by 10.28.158.216 with SMTP id h207mr671015wme.4.1455033242984; Tue, 09 Feb 2016 07:54:02 -0800 (PST) X-BeenThere: outreachy-kernel@googlegroups.com Received: by 10.25.206.208 with SMTP id e199ls72221lfg.109.gmail; Tue, 09 Feb 2016 07:54:02 -0800 (PST) X-Received: by 10.112.168.201 with SMTP id zy9mr4129056lbb.23.1455033242469; Tue, 09 Feb 2016 07:54:02 -0800 (PST) Return-Path: Received: from mout.kundenserver.de (mout.kundenserver.de. [212.227.126.130]) by gmr-mx.google.com with ESMTPS id s132si603490wmd.1.2016.02.09.07.54.02 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Feb 2016 07:54:02 -0800 (PST) Received-SPF: neutral (google.com: 212.227.126.130 is neither permitted nor denied by best guess record for domain of arnd@arndb.de) client-ip=212.227.126.130; Authentication-Results: gmr-mx.google.com; spf=neutral (google.com: 212.227.126.130 is neither permitted nor denied by best guess record for domain of arnd@arndb.de) smtp.mailfrom=arnd@arndb.de Received: from wuerfel.localnet ([78.42.132.4]) by mrelayeu.kundenserver.de (mreue005) with ESMTPSA (Nemesis) id 0LckK3-1ZmAdK47dv-00k6RX; Tue, 09 Feb 2016 16:54:02 +0100 From: Arnd Bergmann To: Julia Lawall Cc: outreachy-kernel@googlegroups.com Subject: Re: [Outreachy kernel] Doubt regarding build warnings Date: Tue, 09 Feb 2016 16:54:01 +0100 Message-ID: <2414518.udrIPO2x22@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: References: <2431688.NvBMsGsSsv@wuerfel> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:JgnskCHMA4gDKmxWfbNQBerZnaRX8+htKJd+y9eB7LZGS1jzcQK vg2NeJSEwL1tMlFrZAWrK7eB2hHkLY1x08sLwlD25E+6JTB2NaCP2S1vCaTowwvnWWZhOca 4F5mpRtlQi/Wc7gQGfhq2MXETKP1/nSJxLDxWwp5tsU8oUHReYxxVJkEVi3lZmZigWTMaU9 XNu1kNI46EvQn7Gz06FyQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:e53pApdickA=:21dL+umEBKo8WslUAF5paL 6ZhQeNxbSGJ/V2HBkAqCg9yVquTfAvsI4U2Upa59TD/6yHn8c7dVeAGySBFKS0xDTBkmF6mJg MNd5F1p/8JLXgNXdQ1sYEaBEl4IZHFvksv1ulp5wTfDuEmYsqC1e9NLHwyj/liJMeKm/RC2dM mbazS8NqEGJQL/UvYbRiSwQfUV+sVAbrk66SXuIdGo34e0COjDaOj4dtoqRZRajIGjXJfSU+w omAZkJGlLzatem1JitfDcVCzRjtQR4qHIymCsL2LUkNJjNROYTR7YU09Dh8jmd3StWuE9x7TP rzgihN5HcLZ7CiydXWtf/1Rwj39mp42VZ/nFOSwvoa5rlZgCJPib1GF50r4MG2rhtZGmAbcmE 00HbeY/4+gDvsOMMvYjP0y0B+489As3Qg+Fbhga5FEtsDMJPllfhBEoH95vqQg7d+bf1Widn6 uZ8gUCKQLW7C+CRGUP4cvQgcN1H6AQj4ItIql5idTL+kz2nAnhe8NUJHKgB26bTCFhL0O0x8S eo005NBjS3/eDHukSBzKqM02tg5zp4PipCrwIY3E70HPZDt3jMShooELPdbgKFUhanR/VV4dj 83ZXqlu4ogeLkJF+TXI/Xx4syr+MWf5amLHJHOKXMU/25T70zP7nxfevVQpjc3Yaml8w8+AwX PqJQKMt1WkiI/cSKEFHJou15o+sETTrqMtOyPDXph096WgP0U8yRM1sJwSKkdKjnUbygZngpY aI0kAZmara5mnq53 On Tuesday 09 February 2016 16:49:31 Julia Lawall wrote: > On Tue, 9 Feb 2016, Arnd Bergmann wrote: > > > On Tuesday 09 February 2016 16:18:55 Julia Lawall wrote: > > > make M=drivers/staging: This seems to try to link the modules in a > > > previously build vmlinux file. > > > > > > Make path/ could be a reasonable choice for a localized change within a > > > single driver, or for a change localized to drivers staging. In any case, > > > as a minimum always check that compilation produces a .o file for every > > > file that your patch changes. If there is no .o file, you have not > > > compiled the file, and you need to look for other compiler options. > > > > Ok, sounds good. I've added a little bit more detail now: > > > > http://kernelnewbies.org/FirstKernelPatch?action=diff&rev2=25&rev1=24 > > Thanks. What is -sj2? > > -s is 'silent', -j2 is used to build on two threads in parallel rather than one. On second thought, I'll remove those again, as this prevents you from seeing which files get built. Arnd