perf: do allow GIT_PERF_* to be overridden again
#1900
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
A common way to run Git's performance benchmarks on repositories other than Git's own repository (which is not exactly large when compared to actually large repositories) is to run them like this: GIT_PERF_LARGE_REPO=/path/to/my/large/repo \ ./p1234-*.sh -ivx Contrary to developers' common expectations, this failed to work when Git was built with a different `GIT_PERF_LARGE_REPO` value specified at build time: That build-time option would have been written to the `GIT-BUILD-OPTIONS` file, which in turn would have been sourced by `test-lib.sh`, which in turn would have been sourced by `perf-lib.sh`, which in turn would have been sourced by the perf test script, _overriding_ the environment variable specified in the way illustrated above. Since perf tests are not run as part of the build, this most likely unintended behavior was not caught and certainly not fixed, as the `GIT_PERF_*` values would have been empty at build-time. However, in 4638e88 (Makefile: use common template for GIT-BUILD-OPTIONS, 2024-12-06), a subtle change of behavior was introduced: Whereas before, a couple of build-time options (the `GIT_PERF_*` ones included) were written to `GIT-BUILD-OPTIONS` only when their values were non-empty. With this commit, they are also written when they are empty. The consequence is that above-mentioned way to run the perf tests will not only fail to pick up the desired `GIT_PERF_*` settings when they were specified differently while building Git, instead the desired settings will be only respected when specified _while building_ Git. Let's work around the original issue, i.e. let `GIT_PERF_*` environment variables override what is recorded in `GIT-BUILD-OPTIONS`. Note that this is just the tip of the iceberg, there are a couple of `GIT_TEST_*` options that may want a similar fix in `test-lib.sh`. Due to time constraints on my side, this here patch focuses exclusively on the `GIT_PERF_*` settings. Signed-off-by: Johannes Schindelin <[email protected]>
|
/submit |
|
Submitted as [email protected] To fetch this version into To fetch this version to local tag |
|
On the Git mailing list, Derrick Stolee wrote (reply to this): On 4/4/2025 6:56 AM, Johannes Schindelin via GitGitGadget wrote:
> From: Johannes Schindelin <[email protected]>
>
> A common way to run Git's performance benchmarks on repositories other
> than Git's own repository (which is not exactly large when compared to
> actually large repositories) is to run them like this:
>
> GIT_PERF_LARGE_REPO=/path/to/my/large/repo \
> ./p1234-*.sh -ivx
>
This issue also extends to other necessary variables such as
GIT_PERF_REPEAT_COUNT.
> +# GIT-BUILD-OPTIONS, sourced by test-lib.sh, overwrites the `GIT_PERF_*`
> +# values that are set by the user (if any). Let's stash them away as
> +# `eval`-able assignments.
> +git_perf_settings="$(env |
> + sed -n "/^GIT_PERF_/{
> + # escape all single-quotes in the value
> + s/'/'\\\\''/g
> + # turn this into an eval-able assignment
> + s/^\\([^=]*=\\)\\(.*\\)/\\1'\\2'/p
> + }")"
> +
> . ../test-lib.sh
> +eval "$git_perf_settings"
I verified this fix in my local environment. Thanks so much for digging
in and finding the solution here!
-Stolee
|
|
User |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This issue was noticed when working on large-scale issues.
Cc: Patrick Steinhardt [email protected]
cc: Derrick Stolee [email protected]