[PATCH v3 0/5] meson: wire up support for benchmarks

[Patrick Steinhardt <ps@pks.im>]

Hi,

this small patch series implements support for running our benchmarks in
"t/perf" via Meson. The series does not aim to replace "t/perf/run",
which is more fully-featured and allows running benchmarks against
multiple different trees. Instead, this series only allows running the
benchmarks against the current tree. Users are thus expected to continue
using "t/perf/run" for more advanced usecases.

Changes in v2:
  - Adapt "aggregate.perl" to use a "/usr/bin/env perl" shebang.
  - Link to v1: https://lore.kernel.org/r/20250331-pks-meson-benchmarks-v1-0-b2ace85616a3@pks.im

Changes in v3:
  - Document how to run benchmarks in "meson.build".
  - Expand the message for the commit that enables out-of-tree
    benchmarking.
  - Link to v2: https://lore.kernel.org/r/20250414-pks-meson-benchmarks-v2-0-04377080a167@pks.im

Thanks!

Patrick

---
Patrick Steinhardt (5):
      t/perf: fix benchmarks with alternate repo formats
      t/perf: use configured PERL_PATH
      t/perf: fix benchmarks with out-of-tree builds
      meson: wire up benchmarks
      meson: wire up benchmarking options

 meson.build           | 13 +++++++--
 meson_options.txt     |  6 ++++
 t/meson.build         | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++
 t/perf/aggregate.perl |  2 +-
 t/perf/perf-lib.sh    | 32 ++++++++++++++++++---
 t/perf/run            |  4 +--
 6 files changed, 124 insertions(+), 10 deletions(-)

Range-diff versus v2:

1:  dad3c5a3e78 = 1:  85098f35716 t/perf: fix benchmarks with alternate repo formats
2:  42284091b9c = 2:  457ea957acf t/perf: use configured PERL_PATH
3:  d03ca0c0630 ! 3:  a66bc5aaf51 t/perf: fix benchmarks with out-of-tree builds
    @@ Commit message
         assumption breaks with both CMake and Meson, where the build directory
         can be located in an arbitrary place.
     
    -    Adapt the script so that it works with out-of-tree builds. This prepares
    -    us for wiring up benchmarks in Meson.
    +    Adapt the script so that it works with out-of-tree builds. Most
    +    importantly, this requires us to figure out the location of the build
    +    directory:
    +
    +      - When running benchmarks via our Makefile the build directory is the
    +        same as the source directory. We already know to derive the test
    +        directory ("t/") via `$(pwd)/..`, which works because we chdir into
    +        "t/perf" before executing benchmarks. We can thus derive the build
    +        directory by appending another "/.." to that path.
    +
    +      - When running benchmarks via Meson the build directory is located at
    +        an arbitrary location. The build system thus has to make the path
    +        known by exporting the `GIT_BUILD_DIR` environment variable.
    +
    +    This change prepares us for wiring up benchmarks in Meson.
     
         Signed-off-by: Patrick Steinhardt <ps@pks.im>
     
4:  14945278066 ! 4:  386b960f3e1 meson: wire up benchmarks
    @@ Commit message
         tests are also accepted when running benchmarks.
     
         Note that the benchmarking target is somewhat limited because it will
    -    only run benchmarks for the current build. Other usecases, like running
    +    only run benchmarks for the current build. Other use cases, like running
         benchmarks against multiple different versions of Git, are not currently
    -    supported. Users should continue to use "t/perf/run" for those usecases.
    -    The script should get extended at one point in time to support Meson,
    -    but this is outside of the scope of this series.
    +    supported. Users should continue to use "t/perf/run" for those use
    +    cases. The script should get extended at one point in time to support
    +    Meson, but this is outside of the scope of this series.
     
         Signed-off-by: Patrick Steinhardt <ps@pks.im>
     
      ## meson.build ##
    +@@
    + #      # Execute single test interactively such that features like `debug ()` work.
    + #      $ meson test -i --test-args='-ix' t1400-update-ref
    + #
    ++#      # Execute all benchmarks.
    ++#      $ meson test -i --benchmark
    ++#
    ++#      # Execute single benchmark.
    ++#      $ meson test -i --benchmark p0000-*
    ++#
    + #   Test execution is parallelized by default and scales with the number of
    + #   processor cores available. You can change the number of processes by passing
    + #   the `-jN` flag to `meson test`.
     @@ meson.build: git = find_program('git', dirs: program_path, required: false)
      sed = find_program('sed', dirs: program_path)
      shell = find_program('sh', dirs: program_path)
5:  101be1e8efc = 5:  cc3e771ada0 meson: wire up benchmarking options

---
base-commit: 683c54c999c301c2cd6f715c411407c413b1d84e
change-id: 20250328-pks-meson-benchmarks-a8fac5f69467