From 9e2163ea45b688e9de4744ebb9b01ea7e1ed8d56 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Sun, 13 May 2007 01:48:47 -0400 Subject: [PATCH] user-manual: move howto/using-topic-branches into manual Move howto/using-topic-branches into the user manual as an example for the "sharing development" chapter. While we're at it, remove some discussion that's covered in earlier chapters, modernize somewhat (use separate-heads setup, remotes, replace "whatchanged" by "log", etc.), and replace syntax we'd need to explain by syntax we've already covered (e.g. old..new instead of new ^old). The result may not really describe what Tony Luck does any more.... Hope that's not annoying. Cc: Tony Luck Signed-off-by: "J. Bruce Fields" --- Documentation/howto/using-topic-branches.txt | 296 ------------------ Documentation/user-manual.txt | 297 ++++++++++++++++++- 2 files changed, 296 insertions(+), 297 deletions(-) delete mode 100644 Documentation/howto/using-topic-branches.txt diff --git a/Documentation/howto/using-topic-branches.txt b/Documentation/howto/using-topic-branches.txt deleted file mode 100644 index 2c98194cb..000000000 --- a/Documentation/howto/using-topic-branches.txt +++ /dev/null @@ -1,296 +0,0 @@ -Date: Mon, 15 Aug 2005 12:17:41 -0700 -From: tony.luck@intel.com -Subject: Some tutorial text (was git/cogito workshop/bof at linuxconf au?) -Abstract: In this article, Tony Luck discusses how he uses GIT - as a Linux subsystem maintainer. - -Here's something that I've been putting together on how I'm using -GIT as a Linux subsystem maintainer. - --Tony - -Last updated w.r.t. GIT 1.1 - -Linux subsystem maintenance using GIT -------------------------------------- - -My requirements here are to be able to create two public trees: - -1) A "test" tree into which patches are initially placed so that they -can get some exposure when integrated with other ongoing development. -This tree is available to Andrew for pulling into -mm whenever he wants. - -2) A "release" tree into which tested patches are moved for final -sanity checking, and as a vehicle to send them upstream to Linus -(by sending him a "please pull" request.) - -Note that the period of time that each patch spends in the "test" tree -is dependent on the complexity of the change. Since GIT does not support -cherry picking, it is not practical to simply apply all patches to the -test tree and then pull to the release tree as that would leave trivial -patches blocked in the test tree waiting for complex changes to accumulate -enough test time to graduate. - -Back in the BitKeeper days I achieved this by creating small forests of -temporary trees, one tree for each logical grouping of patches, and then -pulling changes from these trees first to the test tree, and then to the -release tree. At first I replicated this in GIT, but then I realised -that I could so this far more efficiently using branches inside a single -GIT repository. - -So here is the step-by-step guide how this all works for me. - -First create your work tree by cloning Linus's public tree: - - $ git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git work - -Change directory into the cloned tree you just created - - $ cd work - -Set up a remotes file so that you can fetch the latest from Linus' master -branch into a local branch named "linus": - - $ cat > .git/remotes/linus - URL: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git - Pull: master:linus - ^D - -and create the linus branch: - - $ git branch linus - -The "linus" branch will be used to track the upstream kernel. To update it, -you simply run: - - $ git fetch linus - -you can do this frequently (and it should be safe to do so with pending -work in your tree, but perhaps not if you are in mid-merge). - -If you need to keep track of other public trees, you can add remote branches -for them too: - - $ git branch another - $ cat > .git/remotes/another - URL: ... insert URL here ... - Pull: name-of-branch-in-this-remote-tree:another - ^D - -and run: - - $ git fetch another - -Now create the branches in which you are going to work, these start -out at the current tip of the linus branch. - - $ git branch test linus - $ git branch release linus - -These can be easily kept up to date by merging from the "linus" branch: - - $ git checkout test && git merge "Auto-update from upstream" test linus - $ git checkout release && git merge "Auto-update from upstream" release linus - -Important note! If you have any local changes in these branches, then -this merge will create a commit object in the history (with no local -changes git will simply do a "Fast forward" merge). Many people dislike -the "noise" that this creates in the Linux history, so you should avoid -doing this capriciously in the "release" branch, as these noisy commits -will become part of the permanent history when you ask Linus to pull -from the release branch. - -Set up so that you can push upstream to your public tree (you need to -log-in to the remote system and create an empty tree there before the -first push). - - $ cat > .git/remotes/mytree - URL: master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6.git - Push: release - Push: test - ^D - -and the push both the test and release trees using: - - $ git push mytree - -or push just one of the test and release branches using: - - $ git push mytree test -or - $ git push mytree release - -Now to apply some patches from the community. Think of a short -snappy name for a branch to hold this patch (or related group of -patches), and create a new branch from the current tip of the -linus branch: - - $ git checkout -b speed-up-spinlocks linus - -Now you apply the patch(es), run some tests, and commit the change(s). If -the patch is a multi-part series, then you should apply each as a separate -commit to this branch. - - $ ... patch ... test ... commit [ ... patch ... test ... commit ]* - -When you are happy with the state of this change, you can pull it into the -"test" branch in preparation to make it public: - - $ git checkout test && git merge "Pull speed-up-spinlock changes" test speed-up-spinlocks - -It is unlikely that you would have any conflicts here ... but you might if you -spent a while on this step and had also pulled new versions from upstream. - -Some time later when enough time has passed and testing done, you can pull the -same branch into the "release" tree ready to go upstream. This is where you -see the value of keeping each patch (or patch series) in its own branch. It -means that the patches can be moved into the "release" tree in any order. - - $ git checkout release && git merge "Pull speed-up-spinlock changes" release speed-up-spinlocks - -After a while, you will have a number of branches, and despite the -well chosen names you picked for each of them, you may forget what -they are for, or what status they are in. To get a reminder of what -changes are in a specific branch, use: - - $ git-whatchanged branchname ^linus | git-shortlog - -To see whether it has already been merged into the test or release branches -use: - - $ git-rev-list branchname ^test -or - $ git-rev-list branchname ^release - -[If this branch has not yet been merged you will see a set of SHA1 values -for the commits, if it has been merged, then there will be no output] - -Once a patch completes the great cycle (moving from test to release, then -pulled by Linus, and finally coming back into your local "linus" branch) -the branch for this change is no longer needed. You detect this when the -output from: - - $ git-rev-list branchname ^linus - -is empty. At this point the branch can be deleted: - - $ git branch -d branchname - -Some changes are so trivial that it is not necessary to create a separate -branch and then merge into each of the test and release branches. For -these changes, just apply directly to the "release" branch, and then -merge that into the "test" branch. - -To create diffstat and shortlog summaries of changes to include in a "please -pull" request to Linus you can use: - - $ git-whatchanged -p release ^linus | diffstat -p1 -and - $ git-whatchanged release ^linus | git-shortlog - - -Here are some of the scripts that I use to simplify all this even further. - -==== update script ==== -# Update a branch in my GIT tree. If the branch to be updated -# is "linus", then pull from kernel.org. Otherwise merge local -# linus branch into test|release branch - -case "$1" in -test|release) - git checkout $1 && git merge "Auto-update from upstream" $1 linus - ;; -linus) - before=$(cat .git/refs/heads/linus) - git fetch linus - after=$(cat .git/refs/heads/linus) - if [ $before != $after ] - then - git-whatchanged $after ^$before | git-shortlog - fi - ;; -*) - echo "Usage: $0 linus|test|release" 1>&2 - exit 1 - ;; -esac - -==== merge script ==== -# Merge a branch into either the test or release branch - -pname=$0 - -usage() -{ - echo "Usage: $pname branch test|release" 1>&2 - exit 1 -} - -if [ ! -f .git/refs/heads/"$1" ] -then - echo "Can't see branch <$1>" 1>&2 - usage -fi - -case "$2" in -test|release) - if [ $(git-rev-list $1 ^$2 | wc -c) -eq 0 ] - then - echo $1 already merged into $2 1>&2 - exit 1 - fi - git checkout $2 && git merge "Pull $1 into $2 branch" $2 $1 - ;; -*) - usage - ;; -esac - -==== status script ==== -# report on status of my ia64 GIT tree - -gb=$(tput setab 2) -rb=$(tput setab 1) -restore=$(tput setab 9) - -if [ `git-rev-list release ^test | wc -c` -gt 0 ] -then - echo $rb Warning: commits in release that are not in test $restore - git-whatchanged release ^test -fi - -for branch in `ls .git/refs/heads` -do - if [ $branch = linus -o $branch = test -o $branch = release ] - then - continue - fi - - echo -n $gb ======= $branch ====== $restore " " - status= - for ref in test release linus - do - if [ `git-rev-list $branch ^$ref | wc -c` -gt 0 ] - then - status=$status${ref:0:1} - fi - done - case $status in - trl) - echo $rb Need to pull into test $restore - ;; - rl) - echo "In test" - ;; - l) - echo "Waiting for linus" - ;; - "") - echo $rb All done $restore - ;; - *) - echo $rb "<$status>" $restore - ;; - esac - git-whatchanged $branch ^linus | git-shortlog -done diff --git a/Documentation/user-manual.txt b/Documentation/user-manual.txt index 55d4d37b2..9cc5fc9db 100644 --- a/Documentation/user-manual.txt +++ b/Documentation/user-manual.txt @@ -1789,7 +1789,302 @@ gitweb/INSTALL in the git source tree for instructions on setting it up. Examples -------- -TODO: topic branches, typical roles as in everyday.txt, ? +[[maintaining-topic-branches]] +Maintaining topic branches for a Linux subsystem maintainer +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This describes how Tony Luck uses git in his role as maintainer of the +IA64 architecture for the Linux kernel. + +He uses two public branches: + + - A "test" tree into which patches are initially placed so that they + can get some exposure when integrated with other ongoing development. + This tree is available to Andrew for pulling into -mm whenever he + wants. + + - A "release" tree into which tested patches are moved for final sanity + checking, and as a vehicle to send them upstream to Linus (by sending + him a "please pull" request.) + +He also uses a set of temporary branches ("topic branches"), each +containing a logical grouping of patches. + +To set this up, first create your work tree by cloning Linus's public +tree: + +------------------------------------------------- +$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git work +$ cd work +------------------------------------------------- + +Linus's tree will be stored in the remote branch named origin/master, +and can be updated using gitlink:git-fetch[1]; you can track other +public trees using gitlink:git-remote[1] to set up a "remote" and +git-fetch[1] to keep them up-to-date; see <>. + +Now create the branches in which you are going to work; these start out +at the current tip of origin/master branch, and should be set up (using +the --track option to gitlink:git-branch[1]) to merge changes in from +Linus by default. + +------------------------------------------------- +$ git branch --track test origin/master +$ git branch --track release origin/master +------------------------------------------------- + +These can be easily kept up to date using gitlink:git-pull[1] + +------------------------------------------------- +$ git checkout test && git pull +$ git checkout release && git pull +------------------------------------------------- + +Important note! If you have any local changes in these branches, then +this merge will create a commit object in the history (with no local +changes git will simply do a "Fast forward" merge). Many people dislike +the "noise" that this creates in the Linux history, so you should avoid +doing this capriciously in the "release" branch, as these noisy commits +will become part of the permanent history when you ask Linus to pull +from the release branch. + +A few configuration variables (see gitlink:git-config[1]) can +make it easy to push both branches to your public tree. (See +<>.) + +------------------------------------------------- +$ cat >> .git/config <&2 + exit 1 + ;; +esac +------------------------------------------------- + +------------------------------------------------- +==== merge script ==== +# Merge a branch into either the test or release branch + +pname=$0 + +usage() +{ + echo "Usage: $pname branch test|release" 1>&2 + exit 1 +} + +if [ ! -f .git/refs/heads/"$1" ] +then + echo "Can't see branch <$1>" 1>&2 + usage +fi + +case "$2" in +test|release) + if [ $(git log $2..$1 | wc -c) -eq 0 ] + then + echo $1 already merged into $2 1>&2 + exit 1 + fi + git checkout $2 && git pull . $1 + ;; +*) + usage + ;; +esac +------------------------------------------------- + +------------------------------------------------- +==== status script ==== +# report on status of my ia64 GIT tree + +gb=$(tput setab 2) +rb=$(tput setab 1) +restore=$(tput setab 9) + +if [ `git rev-list test..release | wc -c` -gt 0 ] +then + echo $rb Warning: commits in release that are not in test $restore + git log test..release +fi + +for branch in `ls .git/refs/heads` +do + if [ $branch = test -o $branch = release ] + then + continue + fi + + echo -n $gb ======= $branch ====== $restore " " + status= + for ref in test release origin/master + do + if [ `git rev-list $ref..$branch | wc -c` -gt 0 ] + then + status=$status${ref:0:1} + fi + done + case $status in + trl) + echo $rb Need to pull into test $restore + ;; + rl) + echo "In test" + ;; + l) + echo "Waiting for linus" + ;; + "") + echo $rb All done $restore + ;; + *) + echo $rb "<$status>" $restore + ;; + esac + git log origin/master..$branch | git shortlog +done +------------------------------------------------- [[cleaning-up-history]] -- 2.26.2