Replace MiMalloc w/ default allocator (#900)

Author: adriangb

.github/workflows/ci.yml

@@ -396,14 +396,11 @@ jobs:
           - os: ubuntu
             platform: linux
             target: aarch64
-            # mimalloc not supported on manylinux2014 cross-compile container
-            extra-build-args: --no-default-features
+
           - os: ubuntu
             platform: linux
             target: armv7
             interpreter: 3.7 3.8 3.9 3.10 3.11 3.12
-            # mimalloc not supported on manylinux2014 cross-compile container
-            extra-build-args: --no-default-features
           # musllinux
           - os: ubuntu
             platform: linux
@@ -417,14 +414,10 @@ jobs:
             platform: linux
             target: ppc64le
             interpreter: 3.7 3.8 3.9 3.10 3.11 3.12
-            # mimalloc not supported on manylinux2014 cross-compile container
-            extra-build-args: --no-default-features
           - os: ubuntu
             platform: linux
             target: s390x
             interpreter: 3.7 3.8 3.9 3.10 3.11 3.12
-            # mimalloc not supported on manylinux2014 cross-compile container
-            extra-build-args: --no-default-features
         exclude:
           # Optimized PGO builds for x86_64 manylinux and windows follow a different matrix,
           # maybe in future maturin-action can support this automatically

.github/workflows/codspeed.yml

@@ -50,10 +50,8 @@ jobs:
         uses: Swatinem/rust-cache@v2
 
       - name: Compile pydantic-core for profiling
-        # --no-default-features to avoid using mimalloc
         run: |
-          pip install -e . --config-settings=build-args='--no-default-features --verbose' -v
-          python -c 'import pydantic_core; assert pydantic_core._pydantic_core.__pydantic_core_default_allocator__'
+          pip install -e . --config-settings=build-args='--verbose' -v
         env:
           CONST_RANDOM_SEED: 0 # Fix the compile time RNG seed
           RUSTFLAGS: "-Cprofile-generate=${{ github.workspace }}/profdata"
@@ -65,10 +63,8 @@ jobs:
         run: rustup run stable bash -c '$RUSTUP_HOME/toolchains/$RUSTUP_TOOLCHAIN/lib/rustlib/x86_64-unknown-linux-gnu/bin/llvm-profdata merge -o ${{ github.workspace }}/merged.profdata ${{ github.workspace }}/profdata'
 
       - name: Compile pydantic-core for benchmarking
-        # --no-default-features to avoid using mimalloc
         run: |
-          pip install -e . --config-settings=build-args='--no-default-features --verbose' -v
-          python -c 'import pydantic_core; assert pydantic_core._pydantic_core.__pydantic_core_default_allocator__'
+          pip install -e . --config-settings=build-args='--verbose' -v
         env:
           CONST_RANDOM_SEED: 0 # Fix the compile time RNG seed
           RUSTFLAGS: "-Cprofile-use=${{ github.workspace }}/merged.profdata"

Cargo.lock

@@ -33,8 +33,6 @@ strum_macros = "0.25.2"
 serde_json = {version = "1.0.104", features = ["arbitrary_precision", "preserve_order"]}
 enum_dispatch = "0.3.8"
 serde = { version = "1.0.183", features = ["derive"] }
-# disabled for benchmarks since it makes microbenchmark performance more flakey
-mimalloc = { version = "0.1.30", optional = true, default-features = false, features = ["local_dynamic_tls"] }
 speedate = "0.12.0"
 smallvec = "1.11.0"
 ahash = "0.8.0"
@@ -53,7 +51,6 @@ crate-type = ["cdylib", "rlib"]
 [features]
 # must be enabled when building with `cargo build`, maturin enables this automatically
 extension-module = ["pyo3/extension-module"]
-default = ["mimalloc"]
 
 [profile.release]
 lto = "fat"

Cargo.toml

@@ -6,10 +6,6 @@ use std::sync::OnceLock;
 
 use pyo3::{prelude::*, sync::GILOnceCell};
 
-#[cfg(feature = "mimalloc")]
-#[global_allocator]
-static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
-
 // parse this first to get access to the contained macro
 #[macro_use]
 mod py_gc;
@@ -69,10 +65,9 @@ fn get_pydantic_version(py: Python<'_>) -> Option<&'static str> {
 
 pub fn build_info() -> String {
     format!(
-        "profile={} pgo={} mimalloc={}",
+        "profile={} pgo={}",
         env!("PROFILE"),
         option_env!("RUSTFLAGS").unwrap_or("").contains("-Cprofile-use="),
-        cfg!(feature = "mimalloc")
     )
 }
 
@@ -102,9 +97,5 @@ fn _pydantic_core(py: Python, m: &PyModule) -> PyResult<()> {
     m.add_function(wrap_pyfunction!(to_json, m)?)?;
     m.add_function(wrap_pyfunction!(to_jsonable_python, m)?)?;
     m.add_function(wrap_pyfunction!(list_all_errors, m)?)?;
-
-    #[cfg(not(feature = "mimalloc"))]
-    m.setattr("__pydantic_core_default_allocator__", true)?; // uses setattr so this is not in __all__
-
     Ok(())
 }