Parallelize codspeed

Currently benchmarking takes much longer than the other jobs,
parallelizing it speeds up the time to completion.

Author: seddonym

.github/workflows/main.yml

@@ -55,6 +55,10 @@ jobs:
 
   benchmarks:
       runs-on: ubuntu-22.04
+      strategy:
+        matrix:
+          shard: [1,2]
+
       steps:
         - uses: actions/checkout@v4
 
@@ -74,11 +78,11 @@ jobs:
           run: |
             python -VV
             uv venv
-            uv pip install pytest==7.4.4 pyyaml==6.0.1 pytest-codspeed==3.2.0 Django==5.1.1 /home/runner/work/grimp/grimp         
+            uv pip install pytest==7.4.4 pyyaml==6.0.1 pytest-codspeed==3.2.0 pytest-test-groups==1.2.0 Django==5.1.1 /home/runner/work/grimp/grimp         
 
         - name: Run benchmarks
           uses: CodSpeedHQ/action@v3
           with:
             token: ${{ secrets.CODSPEED_TOKEN }}
             run: |
-              uv run pytest tests/benchmarking/ --codspeed
+              uv run pytest tests/benchmarking/ --codspeed --test-group=${{ matrix.shard }} --test-group-by filename --test-group-count=2

tox.ini

@@ -77,9 +77,10 @@ deps =
     pytest==7.4.4
     pyyaml==6.0.1
     pytest-codspeed==3.2.0
+    pytest-test-groups==1.2.0
     Django==5.1.1
 commands =
-    pytest --codspeed {posargs}
+    pytest --codspeed tests/benchmarking {posargs}
 
 
 [testenv:docs]