use default allocator for benchmarks (#662)

Co-authored-by: David Montague <[email protected]>

Author: adriangb

.github/workflows/codspeed.yml

@@ -46,7 +46,12 @@ jobs:
       - name: cache rust
         uses: Swatinem/rust-cache@v2
 
-      - run: pip install . -v
+      - name: Install pydantic-core
+        # build-prod does not include MiMalloc because it bypasses Maturin
+        run: |
+          pip install -e .
+          make build-prod
+          python -c 'import pydantic_core'
         env:
           CONST_RANDOM_SEED: 0 # Fix the compile time RNG seed
 

Cargo.toml

@@ -51,7 +51,9 @@ crate-type = ["cdylib", "rlib"]
 extension-module = ["pyo3/extension-module"]
 # required for cargo bench
 auto-initialize = ["pyo3/auto-initialize"]
-default = ["mimalloc", "mimalloc/local_dynamic_tls", "pyo3/generate-import-lib", "pyo3/num-bigint"]
+# disabled for benchmarks since it makes microbenchmark performance more flakey
+mimalloc-allocator = ["mimalloc", "mimalloc/local_dynamic_tls"]
+default = ["pyo3/generate-import-lib", "pyo3/num-bigint"]
 
 [profile.release]
 lto = "fat"

pyproject.toml

@@ -46,7 +46,7 @@ Source = 'https://github.com/pydantic/pydantic-core'
 [tool.maturin]
 module-name = "pydantic_core._pydantic_core"
 bindings = 'pyo3'
-features = ["pyo3/extension-module"]
+features = ["pyo3/extension-module", "mimalloc-allocator"]
 
 [tool.ruff]
 line-length = 120

src/lib.rs

@@ -5,7 +5,7 @@ extern crate core;
 
 use pyo3::prelude::*;
 
-#[cfg(feature = "mimalloc")]
+#[cfg(feature = "mimalloc-allocator")]
 #[global_allocator]
 static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;