vortex-data · joseph-isaacs · Jun 17, 2026
diff --git a/vortex-array/benches/aggregate_grouped.rs b/vortex-array/benches/aggregate_grouped.rs
@@ -22,10 +22,12 @@ use vortex_array::arrays::ListViewArray;
 use vortex_array::arrays::PrimitiveArray;
 use vortex_array::arrays::VarBinViewArray;
 use vortex_array::dtype::DType;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_array::validity::Validity;
 use vortex_buffer::Buffer;
 
 fn main() {
+    LEGACY_SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/aggregate_max.rs b/vortex-array/benches/aggregate_max.rs
@@ -9,9 +9,11 @@ use vortex_array::IntoArray;
 use vortex_array::VortexSessionExecute;
 use vortex_array::arrays::PrimitiveArray;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/aggregate_sum.rs b/vortex-array/benches/aggregate_sum.rs
@@ -10,9 +10,11 @@ use vortex_array::VortexSessionExecute;
 use vortex_array::arrays::PrimitiveArray;
 use vortex_array::expr::stats::Stat;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/binary_ops.rs b/vortex-array/benches/binary_ops.rs
@@ -21,9 +21,11 @@ use vortex_array::arrays::PrimitiveArray;
 use vortex_array::builtins::ArrayBuiltins;
 use vortex_array::scalar_fn::fns::operators::Operator;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/bool_zip.rs b/vortex-array/benches/bool_zip.rs
@@ -11,9 +11,11 @@ use vortex_array::RecursiveCanonical;
 use vortex_array::VortexSessionExecute;
 use vortex_array::arrays::BoolArray;
 use vortex_array::builtins::ArrayBuiltins;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_mask::Mask;
 
 fn main() {
+    LEGACY_SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/cast_primitive.rs b/vortex-array/benches/cast_primitive.rs
@@ -15,9 +15,11 @@ use vortex_array::dtype::Nullability;
 use vortex_array::dtype::PType;
 use vortex_array::expr::stats::Stat;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/chunk_array_builder.rs b/vortex-array/benches/chunk_array_builder.rs
@@ -19,10 +19,12 @@ use vortex_array::builders::VarBinViewBuilder;
 use vortex_array::builders::builder_with_capacity;
 use vortex_array::dtype::DType;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_error::VortexExpect;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/chunked_dict_builder.rs b/vortex-array/benches/chunked_dict_builder.rs
@@ -12,10 +12,12 @@ use vortex_array::arrays::dict_test::gen_dict_primitive_chunks;
 use vortex_array::builders::builder_with_capacity;
 use vortex_array::dtype::NativePType;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_error::VortexExpect;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/chunked_fsl_canonicalize.rs b/vortex-array/benches/chunked_fsl_canonicalize.rs
@@ -19,11 +19,13 @@ use vortex_array::VortexSessionExecute;
 use vortex_array::arrays::ChunkedArray;
 use vortex_array::arrays::FixedSizeListArray;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_array::validity::Validity;
 use vortex_buffer::Buffer;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/dict_compare.rs b/vortex-array/benches/dict_compare.rs
@@ -23,9 +23,11 @@ use vortex_array::expr::lit;
 use vortex_array::expr::root;
 use vortex_array::scalar_fn::fns::operators::Operator;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/dict_compress.rs b/vortex-array/benches/dict_compress.rs
@@ -18,9 +18,11 @@ use vortex_array::arrays::dict_test::gen_varbin_words;
 use vortex_array::builders::dict::dict_encode;
 use vortex_array::dtype::NativePType;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/expr/case_when_bench.rs b/vortex-array/benches/expr/case_when_bench.rs
@@ -23,13 +23,15 @@ use vortex_array::expr::lt;
 use vortex_array::expr::nested_case_when;
 use vortex_array::expr::root;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_buffer::Buffer;
 use vortex_session::VortexSession;
 
 static SESSION: LazyLock<VortexSession> =
     LazyLock::new(|| VortexSession::empty().with::<ArraySession>());
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/filter_bool.rs b/vortex-array/benches/filter_bool.rs
@@ -20,11 +20,13 @@ use vortex_array::RecursiveCanonical;
 use vortex_array::VortexSessionExecute;
 use vortex_array::arrays::BoolArray;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_buffer::BitBuffer;
 use vortex_mask::Mask;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/listview_rebuild.rs b/vortex-array/benches/listview_rebuild.rs
@@ -22,11 +22,13 @@ use vortex_array::arrays::listview::ListViewArrayExt;
 use vortex_array::arrays::listview::ListViewRebuildMode;
 use vortex_array::dtype::FieldNames;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_array::validity::Validity;
 use vortex_buffer::Buffer;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/primitive_zip.rs b/vortex-array/benches/primitive_zip.rs
@@ -14,10 +14,12 @@ use vortex_array::RecursiveCanonical;
 use vortex_array::VortexSessionExecute;
 use vortex_array::arrays::PrimitiveArray;
 use vortex_array::builtins::ArrayBuiltins;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_buffer::BufferMut;
 use vortex_mask::Mask;
 
 fn main() {
+    LEGACY_SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/scalar_at_struct.rs b/vortex-array/benches/scalar_at_struct.rs
@@ -16,11 +16,13 @@ use vortex_array::VortexSessionExecute;
 use vortex_array::arrays::StructArray;
 use vortex_array::dtype::FieldNames;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_array::validity::Validity;
 use vortex_buffer::Buffer;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/scalar_subtract.rs b/vortex-array/benches/scalar_subtract.rs
@@ -18,10 +18,12 @@ use vortex_array::arrays::ConstantArray;
 use vortex_array::builtins::ArrayBuiltins;
 use vortex_array::scalar_fn::fns::operators::Operator;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_buffer::Buffer;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/take_filter.rs b/vortex-array/benches/take_filter.rs
@@ -31,6 +31,7 @@ use vortex_array::VortexSessionExecute;
 use vortex_array::arrays::ListArray;
 use vortex_array::arrays::PrimitiveArray;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_array::validity::Validity;
 use vortex_buffer::BitBuffer;
 use vortex_buffer::BitBufferMut;
@@ -39,6 +40,7 @@ use vortex_mask::Mask;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/take_fsl.rs b/vortex-array/benches/take_fsl.rs
@@ -21,11 +21,13 @@ use vortex_array::RecursiveCanonical;
 use vortex_array::VortexSessionExecute;
 use vortex_array::arrays::FixedSizeListArray;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_array::validity::Validity;
 use vortex_buffer::Buffer;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/take_patches.rs b/vortex-array/benches/take_patches.rs
@@ -17,10 +17,12 @@ use vortex_array::ToCanonical as _;
 use vortex_array::VortexSessionExecute;
 use vortex_array::patches::Patches;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_buffer::Buffer;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/take_primitive.rs b/vortex-array/benches/take_primitive.rs
@@ -20,9 +20,11 @@ use vortex_array::VortexSessionExecute;
 use vortex_array::arrays::DictArray;
 use vortex_array::arrays::PrimitiveArray;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/take_struct.rs b/vortex-array/benches/take_struct.rs
@@ -16,11 +16,13 @@ use vortex_array::VortexSessionExecute;
 use vortex_array::arrays::StructArray;
 use vortex_array::dtype::FieldNames;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_array::validity::Validity;
 use vortex_buffer::Buffer;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/to_arrow.rs b/vortex-array/benches/to_arrow.rs
@@ -26,9 +26,11 @@ use vortex_array::dtype::Nullability;
 use vortex_array::dtype::PType;
 use vortex_array::dtype::StructFields;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/benches/varbinview_zip.rs b/vortex-array/benches/varbinview_zip.rs
@@ -14,10 +14,12 @@ use vortex_array::builtins::ArrayBuiltins;
 use vortex_array::dtype::DType;
 use vortex_array::dtype::Nullability;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_mask::Mask;
 use vortex_session::VortexSession;
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex-array/src/test_harness.rs b/vortex-array/src/test_harness.rs
@@ -7,11 +7,28 @@ use goldenfile::Mint;
 use goldenfile::differs::binary_diff;
 use itertools::Itertools;
 use vortex_error::VortexResult;
+use vortex_session::SessionExt;
 
 use crate::LEGACY_SESSION;
 use crate::VortexSessionExecute;
 use crate::arrays::BoolArray;
 use crate::arrays::bool::BoolArrayExt;
+use crate::optimizer::kernels::ArrayKernels;
+
+/// Extension trait for warming session variables before a benchmark's measured region.
+///
+/// The first access to a session variable inserts its default value. Performing that one-time
+/// insertion inside a benchmark's measured loop charges it to the first measured iteration, which
+/// is a problem under CodSpeed's instruction-count simulation. Calling [`Self::warm_kernels`]
+/// before the bench loop moves the [`ArrayKernels`] insertion into setup instead.
+pub trait WarmKernelsExt: SessionExt {
+    /// Eagerly initialize the optimizer [`ArrayKernels`] on this session.
+    fn warm_kernels(&self) {
+        drop(self.get::<ArrayKernels>());
+    }
+}
+
+impl<S: SessionExt> WarmKernelsExt for S {}
 
 /// Check that a named metadata matches its previous versioning.
 ///

diff --git a/vortex-compressor/benches/dict_encode.rs b/vortex-compressor/benches/dict_encode.rs
@@ -12,6 +12,7 @@ use vortex_array::arrays::BoolArray;
 use vortex_array::arrays::PrimitiveArray;
 use vortex_array::builders::dict::dict_encode;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_array::validity::Validity;
 use vortex_buffer::BufferMut;
 use vortex_compressor::builtins::integer_dictionary_encode;
@@ -55,5 +56,6 @@ fn encode_specialized(bencher: Bencher) {
 }
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main()
 }
diff --git a/vortex-row/benches/row_encode.rs b/vortex-row/benches/row_encode.rs
@@ -34,6 +34,7 @@ use vortex_array::arrays::PrimitiveArray;
 use vortex_array::arrays::StructArray;
 use vortex_array::arrays::VarBinViewArray;
 use vortex_array::session::ArraySession;
+use vortex_array::test_harness::WarmKernelsExt;
 use vortex_row::RowEncoder;
 use vortex_session::VortexSession;
 
@@ -46,6 +47,7 @@ static SESSION: LazyLock<VortexSession> =
     LazyLock::new(|| VortexSession::empty().with::<ArraySession>());
 
 fn main() {
+    SESSION.warm_kernels();
     divan::main();
 }
 

diff --git a/vortex/benches/common_encoding_tree_throughput.rs b/vortex/benches/common_encoding_tree_throughput.rs
@@ -24,6 +24,7 @@ use vortex::array::arrays::VarBinArray;
 use vortex::array::arrays::VarBinViewArray;
 use vortex::array::arrays::varbin::VarBinArrayExt;
 use vortex::array::builtins::ArrayBuiltins;
+use vortex::array::optimizer::kernels::ArrayKernels;
 use vortex::array::session::ArraySession;
 use vortex::dtype::DType;
 use vortex::dtype::PType;
@@ -44,12 +45,14 @@ use vortex::encodings::runend::RunEnd;
 use vortex::encodings::runend::RunEndArrayExt;
 use vortex::error::VortexExpect;
 use vortex::extension::datetime::TimeUnit;
+use vortex_session::SessionExt;
 use vortex_session::VortexSession;
 
 #[global_allocator]
 static GLOBAL: MiMalloc = MiMalloc;
 
 fn main() {
+    drop(SESSION.get::<ArrayKernels>());
     divan::main();
 }