Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760372AbYGQStY (ORCPT ); Thu, 17 Jul 2008 14:49:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756722AbYGQStO (ORCPT ); Thu, 17 Jul 2008 14:49:14 -0400 Received: from vms046pub.verizon.net ([206.46.252.46]:50080 "EHLO vms046pub.verizon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754513AbYGQStN (ORCPT ); Thu, 17 Jul 2008 14:49:13 -0400 Date: Thu, 17 Jul 2008 14:49:04 -0400 (EDT) From: Len Brown Subject: Re: Please pull ACPI updates In-reply-to: X-X-Sender: lenb@localhost.localdomain To: Linus Torvalds Cc: Andi Kleen , Jesse Barnes , "Rafael J. Wysocki" , Linux Kernel Mailing List , linux-acpi@vger.kernel.org Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII References: <20080716214516.GA10777@basil.nowhere.org> <200807170011.12184.rjw@sisk.pl> <200807161633.01375.jbarnes@virtuousgeek.org> <487EE940.1050007@firstfloor.org> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3501 Lines: 99 Andi, Jesse, Linus, Thanks for working through this while I'm away. Patches with cross-tree dependencies happen, and they continue to be a challenge to our process. We don't really have an organized way to handle them. It seems that every time they are a communication challenge and I'm sorry I wasn't there to hold up my end of the communication on this merge. Jesse, I use Tony Luck's topic-branch scheme, now part of the git manual: http://www.kernel.org/pub/software/scm/git/docs/user-manual.html#maintaining-topic-branches Re: updating history in git yes, this is an sort of an oxymoron, but it is necessary for a "middle-man" maintainer. On one hand, we need to test exactly what is checked in, and on the other hand, not every test passes... So we need to revise what we checked in before it goes upstream and becomes permanent history. The alternative would be to check in a lot of reverts and incremental patches that make the final history sent to linus really confusing. I find that the topic branches help a lot with this. My "test" branch is the merge of a bunch of topic branches. If a topic branch turns out to be bad, I can re-merge my test branch from those topics, excluding the bad one. (or including a revised replacement). All the branches besides the revised one maintain their place in history. So if they used to work, they shoulds still work. Of course the merge itself can go bad... But my topic branches are as independent as possible, so this is rare. Customers of my test branch know that it can be re-based. mm and linux-next are the main customers, and since they re-merge from scratch each time, they're immune. Individual developers simply deal with it as a diff, say by using the plain-patch I export, or I do something special for them. Sometimes I re-base topic branches to make creating a diff of them versus a well known snapshot (eg an -rc) easy. This is particularly useful for topic branches that take a long time to go upstream b/c sometimes people want to test them, but only against a recent baseline. Branches pulled into "release" for linus are frozen, or course, since Linus' tree is permanent history. So any reverts/updates after that point have to be real revert commits and incremental patches. cheers, -Len ps. One thing I wish I had in git is a way to make this sequence easier... Say I have a big topic branch with 30 patches in it. The 3rd patch turns out to have a bug in it, but the rest of the series is okay. Today I invoke gitk on the branch and keep that open. Then I create a new topic branch at the broken patch. I always consult ~/src/git/Documentation/git-reset.txt so I can remember the following sequence... $ git reset --soft HEAD^ $ edit $ git commit -a -c ORIG_HEAD Now I've got the fixed 3rd patch checked in, but 27 patches in the original branch are hanging off the original broken 3rd patch. So I git-cherry-pick 27 patches I hope I get them in the right order and don't miss any... It would be nice if we could somehow git rebase those 27 patches in a single command, but if we do, that pulls with it the broken 3rd patch. come to think of it, I can probably export 4..27 as an mbox and then import it on top of the new 3, maybe that is what others do. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/