From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id E520271 for ; Fri, 15 Jul 2016 05:52:51 +0000 (UTC) Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 153BE12D for ; Fri, 15 Jul 2016 05:52:51 +0000 (UTC) From: NeilBrown To: Greg KH , Guenter Roeck Date: Fri, 15 Jul 2016 15:52:39 +1000 In-Reply-To: <20160715042938.GA5527@kroah.com> References: <718BE1FD-6169-4205-A905-53F997D5943A@primarydata.com> <5785C80F.4030707@linaro.org> <20160713090739.GA18037@kroah.com> <20160713143447.GH9976@sirena.org.uk> <20160714031753.GA28722@kroah.com> <20160714100603.GJ9976@sirena.org.uk> <20160715002239.GA31603@kroah.com> <5788337F.8000500@roeck-us.net> <20160715014103.GA5791@kroah.com> <578850EB.3090109@roeck-us.net> <20160715042938.GA5527@kroah.com> Message-ID: <874m7rcus8.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Cc: James Bottomley , Trond Myklebust , "ksummit-discuss@lists.linuxfoundation.org" Subject: Re: [Ksummit-discuss] [CORE TOPIC] kernel unit testing List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-=-= Content-Type: text/plain On Fri, Jul 15 2016, Greg KH wrote: > On Thu, Jul 14, 2016 at 07:56:43PM -0700, Guenter Roeck wrote: >> Overall, I can not imagine that it is even possible to use quilt trees as basis >> for development in a company with if active kernel development, even more so >> if a large number of engineers and/or a number of branches are involved. >> Sure, the QCOM example may be extreme, but do you really think that writing >> those 2.5M LOC would have been possible if QCOM had used Quilt trees instead >> of git ? Using Quilt would for sure have prevented them from writing those >> 2.5M LOC, but then there would be nothing. That doesn't sound like a feasible >> alternative either. > > It is possible, look at the Red Hat and SuSE kernel development teams. > Yes, in the end, most of the patches are backports from upstream, but You are glossing over a key point. We (or at least I as a SUSE kernel developer) don't use quilt for development because, like Guenter says, it would be too clumsy. I do development upstream if git. Upstream first. And I have scripts to help turn the result into something suitable for quilt, making the use of quilt a pain rather than a nightmare. I do find quilt useful when backporting a series of patches so that I can resolve the conflicts on each patch individually and move backwards and forwards through the list of patches. I don't think git has an easy way to store a branch of patches-that-I-need-to-apply and to then give me one at a time, removing them from the branch. I could use 'stgit' for that if necessary, though it is very tempting to write something that is better integrated with git. > during new releases they use quilt for all of their work, adding and > removing and updating patches all the time. So you are saying quilt is good for release management, and Guenter is saying it is bad for development. Maybe you are in agreement. It probably is quite useful when pulling in a new -stable base. We typically have a bunch of patches that we applied before they came out in -stable, and just removing them has some value ... though occasionally I do wonder "what happened to that patch..... oh, stable!". Personally, I would rather do all my kernel development (and non-kernel development) using git and git only. Other engineers might have different opinions. But we work with what we have. NeilBrown > > There are the usual merge issues with doing that, but for an SoC, I > don't think that would be all that hard given that almost all patches > are driver/subsystem-specific and don't touch other places. > > It does take a better calibre of developer to do this type of thing, > that might be a harder thing to deal with at some SoC vendors :) > > thanks, > > greg k-h > _______________________________________________ > Ksummit-discuss mailing list > Ksummit-discuss@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/ksummit-discuss --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJXiHonAAoJEDnsnt1WYoG5J2IQAKgABzpcPrmEtHvHI6zA1f6L XgbCBqHWHP9ja/+FTlSpvsHipczMh1B5T1nszHIcLih69oPiDLi7DO+eaPezKG3O +V0bANGybcUQB6n+qH3ELqozT9i6ucezQ9uXl/8b27hTU4GJmhHpuO4dJ6PzG+3c PSEYlJq2PYACGOiYlk/iiQZg/p8LF1Bcle+HfFC2m+neXzO2quJQPVpSslICBQNq Rf+2wSPAE6JaOaDi+nAGYVYendTMGAuUzJez9dqRsLlsPiXjJyslvFCmIxBIX6Ei at5hJ3hXxqZ+RHAez8fTjggmN9SNGA0FS5ngrUJUj/rdAOMM2cWzsAyVeB42oOXt v5p7qcsswwfS8zTFlb8/mUJraHxvPcu7TLrdL7XJUIz4erjF9Gj20YxnfKi3trno Xw50bPGxT2Qag1TLpe92Pc9CqsBm7DF8cPJEsLzV8rqAyc+TJlmze4jc5W5pC2p8 f4Dbn91DobF978gGPCMqmvx21UjO4NnXpaJD1f6KDK0p4SwJsAdd8RlwhhvojMc6 C9ZE0Gf0A8l27KSsdZVW3/K6RH1ZJf9vKtaaUf5O7VfKelV9gOqZCYXAm3iCob3F pTitVNapj9LL8LeoJWUdzv/Yn0AAZNlTOOR4uV1pBP1dcF3BwIX7teoXWIYJWQKB UzTK32A5OHJ4p/vrG4/r =i5z/ -----END PGP SIGNATURE----- --=-=-=--