threads / patch / 62656

patchGitHub ci(windows): speed up initializing Git for Windows' minimal SDK again

Subject: [PATCH] GitHub ci(windows): speed up initializing Git for Windows' minimal SDK again

## tl;dr

4 messages between Dec 17, 2024 and Dec 19, 2024. Diffs are folded; open one to read it.

replies: 3people: 3as markdown or json

Johannes Schindelin via GitGitGadget· Dec 17, 2024, 14:57 UTC · lore
From: Johannes Schindelin <johannes.schindelin@gmx.de>

It used to be the case that initializing the minimal SDK (i.e. a radically slimmed-down subset of Git for Windows' development environment intended to perform the CI builds and little else) took a bit over one minute, would then be cached, and subsequent jobs would take at most half a dozen seconds to initialize said minimal SDK.

It is important that this step is fast because we have to run the test suite in parallel, in a set of matrix jobs, to offset the slowness of the shell-based test suite, and each and every job has to initialize the very same minimal SDK.

While it may sound as if parallelizing the jobs might only waste the generously-provided build minutes but at least the _wallclock_ time would pass quick, in reality it matters a lot: Frequently Git for Windows' or GitGitGadget PRs get stuck waiting for quite a while before CI builds start because other PRs' builds still spend substantial amounts of time to run, blocking due to the concurrency limit being reached.

Since 91839a88277 (ci: create script to set up Git for Windows SDK, 2024-10-09), the situation has worsened: every job that requires the minimal Git for Windows SDK spends roughly two-and-a-half minutes doing so.

With the switch away from the GitHub Action `setup-git-for-windows-sdk`, we incurred more downsides:

- It is no longer possible for said Action to fix problems independently
  from the Git repository, e.g. when new rules about GitHub Actions
  require changes in the way the minimal SDK is initialized.
- The minimal SDK was installed specifically outside of the worktree so
  as not to clutter it nor incur an additional cost to verify that the
  worktree is clean.

Therefore, even if it would be nice to have a shared process between GitHub and GitLab based CI builds, let's switch the GitHub-based CI back to the tried-and-tested `setup-git-for-windows-sdk` Action.

This commit partially reverts 91839a88277 (ci: create script to set up Git for Windows SDK, 2024-10-09).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
    Speed up the Git for Windows SDK initialization again
    
    While waiting for way too many builds in
    https://github.com/gitgitgadget/git/actions to finish, I noticed that
    the minimal Git for Windows SDK initialization now takes a whopping 2.5
    minutes. That's way too much. It used to take a little over a minute
    when uncached, and 2-5 seconds when cached.
    
    Let's fix this regression by reverting to using the
    setup-git-for-windows-sdk GitHub Action (also because that Action will
    soon see another dramatic speed-up, see
    https://github.com/git-for-windows/setup-git-for-windows-sdk/pull/965).
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1841%2Fdscho%2Fci-windows-jobs-speedup-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1841/dscho/ci-windows-jobs-speedup-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1841
 .github/workflows/main.yml | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)
Show changes to .github/workflows/main.yml +6 −10
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 9301a1edd6d..916a64b6736 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -113,15 +113,13 @@ jobs:
       cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     steps:
     - uses: actions/checkout@v4
-    - name: setup SDK
-      shell: powershell
-      run: ci/install-sdk.ps1
+    - uses: git-for-windows/setup-git-for-windows-sdk@v1
     - name: build
-      shell: powershell
+      shell: bash
       env:
         HOME: ${{runner.workspace}}
         NO_PERL: 1
-      run: git-sdk/usr/bin/bash.exe -l -c 'ci/make-test-artifacts.sh artifacts'
+      run: . /etc/profile && ci/make-test-artifacts.sh artifacts
     - name: zip up tracked files
       run: git archive -o artifacts/tracked.tar.gz HEAD
     - name: upload tracked files and build artifacts
@@ -149,12 +147,10 @@ jobs:
     - name: extract tracked files and build artifacts
       shell: bash
       run: tar xf artifacts.tar.gz && tar xf tracked.tar.gz
-    - name: setup SDK
-      shell: powershell
-      run: ci/install-sdk.ps1
+    - uses: git-for-windows/setup-git-for-windows-sdk@v1
     - name: test
-      shell: powershell
-      run: git-sdk/usr/bin/bash.exe -l -c 'ci/run-test-slice.sh ${{matrix.nr}} 10'
+      shell: bash
+      run: . /etc/profile && ci/run-test-slice.sh ${{matrix.nr}} 10
     - name: print test failures
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
       shell: bash

base-commit: 631ddbbcbd912530e1b78e5d782e72879f7f1fb2
-- 
gitgitgadget
Junio C Hamano· Dec 17, 2024, 20:33 UTC · re: Johannes Schindelin via GitGitGadget · lore

Re: [PATCH] GitHub ci(windows): speed up initializing Git for Windows' minimal SDK again

"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com> writes:

> This commit partially reverts 91839a88277 (ci: create script to set up
> Git for Windows SDK, 2024-10-09).
Thanks, will queue.
Show 41 quoted lines
> diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
> index 9301a1edd6d..916a64b6736 100644
> --- a/.github/workflows/main.yml
> +++ b/.github/workflows/main.yml
> @@ -113,15 +113,13 @@ jobs:
>        cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
>      steps:
>      - uses: actions/checkout@v4
> -    - name: setup SDK
> -      shell: powershell
> -      run: ci/install-sdk.ps1
> +    - uses: git-for-windows/setup-git-for-windows-sdk@v1
>      - name: build
> -      shell: powershell
> +      shell: bash
>        env:
>          HOME: ${{runner.workspace}}
>          NO_PERL: 1
> -      run: git-sdk/usr/bin/bash.exe -l -c 'ci/make-test-artifacts.sh artifacts'
> +      run: . /etc/profile && ci/make-test-artifacts.sh artifacts
>      - name: zip up tracked files
>        run: git archive -o artifacts/tracked.tar.gz HEAD
>      - name: upload tracked files and build artifacts
> @@ -149,12 +147,10 @@ jobs:
>      - name: extract tracked files and build artifacts
>        shell: bash
>        run: tar xf artifacts.tar.gz && tar xf tracked.tar.gz
> -    - name: setup SDK
> -      shell: powershell
> -      run: ci/install-sdk.ps1
> +    - uses: git-for-windows/setup-git-for-windows-sdk@v1
>      - name: test
> -      shell: powershell
> -      run: git-sdk/usr/bin/bash.exe -l -c 'ci/run-test-slice.sh ${{matrix.nr}} 10'
> +      shell: bash
> +      run: . /etc/profile && ci/run-test-slice.sh ${{matrix.nr}} 10
>      - name: print test failures
>        if: failure() && env.FAILED_TEST_ARTIFACTS != ''
>        shell: bash
>
> base-commit: 631ddbbcbd912530e1b78e5d782e72879f7f1fb2
Patrick Steinhardt· Dec 18, 2024, 05:56 UTC · re: Junio C Hamano · lore

Re: [PATCH] GitHub ci(windows): speed up initializing Git for Windows' minimal SDK again

On Tue, Dec 17, 2024 at 12:33:10PM -0800, Junio C Hamano wrote:
Show 7 quoted lines
> "Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
> writes:
> 
> > This commit partially reverts 91839a88277 (ci: create script to set up
> > Git for Windows SDK, 2024-10-09).
> 
> Thanks, will queue.

Okay. Too bad that things regressed this badly with the change. I agree that reverting is the right thing to do for now. I may revisit this again in the next release cycle to investigate whether we can get it up to par with the GitHub Actions. It would be great if the build infra was shared between our CIs, so I think there's some value in it. But if the answer is "no" then I guess that's ultimately fine, as well.

Thanks!
Patrick
Johannes Schindelin· Dec 19, 2024, 13:20 UTC · re: Patrick Steinhardt · lore

Re: [PATCH] GitHub ci(windows): speed up initializing Git for Windows' minimal SDK again

Hi Patrick,
On Wed, 18 Dec 2024, Patrick Steinhardt wrote:
Show 13 quoted lines
> On Tue, Dec 17, 2024 at 12:33:10PM -0800, Junio C Hamano wrote:
> > "Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
> > writes:
> >
> > > This commit partially reverts 91839a88277 (ci: create script to set up
> > > Git for Windows SDK, 2024-10-09).
> >
> > Thanks, will queue.
>
> Okay. Too bad that things regressed this badly with the change. I agree
> that reverting is the right thing to do for now. I may revisit this
> again in the next release cycle to investigate whether we can get it up
> to par with the GitHub Actions.
The way I implemented it should be eminently possible in PowerShell, too.

Something like `Start-Process`, launching not an `Invoke-WebRequest` but instead `C:\Windows\system32\curl.exe` [*1*] to download the `.tar.gz` file (not the `.zip` file, more about that below). Another `Start-Process` should then be opened that executes `tar.exe` [*2*], and then the `stdout` of the former should be piped to the latter [*3*].

I do think that it makes a lot of sense to start extracting as soon as the first byte arrives instead of storing the archive as a temporary file and extracting it only once it has arrived completely.

Now, why not use the `.zip` file instead of the `.tar.gz` file? In my analysis [*4*], I pointed out that the `.zip` file is about 10MB smaller, after all, and BSD tar (at least the version in `C:\Windows\system32`) is able to handle those, too, right? Not so fast. In my experiments, when streaming the `.zip` file to the `tar.exe -xf -` process, the `etc/` and `.sparse/` directories were consistently dropped. A bug, I guess. I ran out of time to investigate this in more depth.

Since the artifacts are now hosted in a GitHub Release and updated regularly, and since those updates cannot be atomic (you can only upload a release asset if no asset of the same name exists already, read: the automation has to _delete_ that asset before uploading a new version), it would also be good to kind of expect that the file may be intermittently absent and add a back-off strategy [*5*].

> It would be great if the build infra was shared between our CIs, so I
> think there's some value in it. But if the answer is "no" then I guess
> that's ultimately fine, as well.

It _could_ be done. But the advantages of having it versioned outside of the Git repository outweigh the benefits of that shared infrastructure, I believe.

Ciao, Johannes

Footnote *1*: https://github.com/git-for-windows/setup-git-for-windows-sdk/pull/965/commits/6db65223de699c4f75ab083f82f43947a53ad6ff#diff-6855ef61b94227f9264adab3ff9f2de95c2d7b4e451019cc0105896d32550eb0R58-R73

Footnote *2*: https://github.com/git-for-windows/setup-git-for-windows-sdk/pull/965/commits/6db65223de699c4f75ab083f82f43947a53ad6ff#diff-6855ef61b94227f9264adab3ff9f2de95c2d7b4e451019cc0105896d32550eb0R77-R86

Footnote *3*: https://github.com/git-for-windows/setup-git-for-windows-sdk/pull/965/commits/6db65223de699c4f75ab083f82f43947a53ad6ff#diff-6855ef61b94227f9264adab3ff9f2de95c2d7b4e451019cc0105896d32550eb0R88

Footnote *4*: https://github.com/git-for-windows/git-sdk-64/pull/87/commits/fdb0cea373893ce7d40bcfcfbeb7fd091a3c4020

Footnote *5*: https://github.com/git-for-windows/setup-git-for-windows-sdk/pull/965/commits/3d4ea07041d0740b21160a9d9a4181f569e706d8

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