From b2f95d37338a09166e9fd4e507eb355c1dd11bc7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Antonio=20S=C3=A1nchez?= <cantonios@google.com>
Date: Sat, 14 Mar 2026 15:43:24 +0000
Subject: [PATCH] Fix more cache size queries.

libeigen/eigen!2295
---
 Eigen/Core     | 7 +++++--
 test/redux.cpp | 5 +++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/Eigen/Core b/Eigen/Core
index ccf7a0c1a..47d599cd0 100644
--- a/Eigen/Core
+++ b/Eigen/Core
@@ -129,8 +129,11 @@
 #include <intrin.h>
 #endif
 
-// Required for querying cache sizes on macOS.
-#if EIGEN_OS_MAC
+// Required for querying cache sizes on Linux and macOS.
+#if EIGEN_OS_LINUX
+#include <unistd.h>
+#elif EIGEN_OS_MAC
+#include <sys/types.h>
 #include <sys/sysctl.h>
 #endif
 
diff --git a/test/redux.cpp b/test/redux.cpp
index a952d67c9..fa1ff994f 100644
--- a/test/redux.cpp
+++ b/test/redux.cpp
@@ -14,8 +14,8 @@
 
 #include "main.h"
 
-template <typename MatrixType>
-void matrixRedux(const MatrixType& m) {
+    template <typename MatrixType>
+    void matrixRedux(const MatrixType& m) {
   typedef typename MatrixType::Scalar Scalar;
   typedef typename MatrixType::RealScalar RealScalar;
 
@@ -318,6 +318,7 @@ EIGEN_DECLARE_TEST(redux) {
     // bool packets are typically 16 bytes (SSE) or 32 bytes (AVX).
     // Test sizes around common packet sizes to catch off-by-one in remainder loops.
     const Index bsizes[] = {1, 2, 3, 7, 8, 9, 15, 16, 17, 31, 32, 33, 63, 64, 65, 127, 128, 129};
+    EIGEN_UNUSED_VARIABLE(bsizes);
     for (int si = 0; si < 18; ++si) {
       CALL_SUBTEST_11(boolRedux(bsizes[si], 1));  // column vector
       CALL_SUBTEST_11(boolRedux(1, bsizes[si]));  // row vector