diff --git a/.github/workflows/build-reusable.yml b/.github/workflows/build-reusable.yml
index f87b4ba39097..6a87cca74cfc 100644
--- a/.github/workflows/build-reusable.yml
+++ b/.github/workflows/build-reusable.yml
@@ -332,8 +332,8 @@ jobs:
           $env:GITHUB_SHA = "${{ inputs.build_ref }}"
           $env:PACKAGE_JSON_ARCH = "${{matrix.package_json_arch}}"
           $env:GITHUB_REPOSITORY = "${{ github.repository }}"
-          $baselineArg = if ("${{ matrix.baseline }}" -eq "true") { @("-Baseline") } else { @() }
-          ./windows-release.ps1 -Platform ${{matrix.platform}} @baselineArg
+          $Baseline = "${{ matrix.baseline }}" -eq "true"
+          ./windows-release.ps1 -Platform ${{matrix.platform}} -Baseline:$Baseline
       - uses: actions/upload-artifact@v4
         with:
           name: ${{matrix.label}}
diff --git a/Source/WTF/wtf/PageBlock.h b/Source/WTF/wtf/PageBlock.h
index c4f9a8b1a4b3..46a31bf8ab79 100644
--- a/Source/WTF/wtf/PageBlock.h
+++ b/Source/WTF/wtf/PageBlock.h
@@ -47,13 +47,14 @@ namespace WTF {
 // On Linux, Power systems normally use 64 KiB pages.
 //
 // aarch64 systems seem to be all over the place. Most Linux distros use 4 KiB, but RHEL uses
-// 64 KiB. Linux on Apple Silicon uses 16KiB for best performance, so use that for Linux on
-// aarch64 by default. USE(64KB_PAGE_BLOCK) allows overriding this.
+// 64 KiB. Since we cannot know the page size at compile time on Linux, use 64 KiB as the ceiling
+// for Linux ARM64 to support all possible page size configurations (4 KiB, 16 KiB, 64 KiB).
+// USE(64KB_PAGE_BLOCK) allows overriding this on other architectures too.
 //
 // Use 64 KiB for any unknown CPUs to be conservative.
-#if OS(DARWIN) || PLATFORM(PLAYSTATION) || CPU(MIPS) || CPU(MIPS64) || CPU(LOONGARCH64) || (OS(LINUX) && CPU(ARM64) && !USE(64KB_PAGE_BLOCK))
+#if OS(DARWIN) || PLATFORM(PLAYSTATION) || CPU(MIPS) || CPU(MIPS64) || CPU(LOONGARCH64)
 constexpr size_t CeilingOnPageSize = 16 * KB;
-#elif USE(64KB_PAGE_BLOCK) || CPU(PPC) || CPU(PPC64) || CPU(PPC64LE) || CPU(UNKNOWN)
+#elif USE(64KB_PAGE_BLOCK) || (OS(LINUX) && CPU(ARM64)) || CPU(PPC) || CPU(PPC64) || CPU(PPC64LE) || CPU(UNKNOWN)
 constexpr size_t CeilingOnPageSize = 64 * KB;
 #elif OS(WINDOWS) || CPU(X86) || CPU(X86_64) || CPU(ARM) || CPU(ARM64) || CPU(RISCV64)
 constexpr size_t CeilingOnPageSize = 4 * KB;
diff --git a/Source/bmalloc/bmalloc/BPlatform.h b/Source/bmalloc/bmalloc/BPlatform.h
index abf75cb0ed38..28eb89f28f0b 100644
--- a/Source/bmalloc/bmalloc/BPlatform.h
+++ b/Source/bmalloc/bmalloc/BPlatform.h
@@ -454,6 +454,10 @@
 #define BUSE_PRECOMPUTED_CONSTANTS_VMPAGE16K 1
 #endif
 
+#if !defined(BUSE_PRECOMPUTED_CONSTANTS_VMPAGE64K)
+#define BUSE_PRECOMPUTED_CONSTANTS_VMPAGE64K 1
+#endif
+
 /* We only export the mallocSize and mallocGoodSize APIs if they're supported by the SystemHeap allocator (currently only Darwin) and the current bmalloc allocator (currently only libpas). */
 #if BUSE(LIBPAS) && BOS(DARWIN)
 #define BENABLE_MALLOC_SIZE 1
diff --git a/Source/bmalloc/libpas/src/libpas/jit_heap_config.h b/Source/bmalloc/libpas/src/libpas/jit_heap_config.h
index 036b1430ae55..88cee8804d73 100644
--- a/Source/bmalloc/libpas/src/libpas/jit_heap_config.h
+++ b/Source/bmalloc/libpas/src/libpas/jit_heap_config.h
@@ -40,16 +40,26 @@ PAS_BEGIN_EXTERN_C;
 #define JIT_SMALL_SEGREGATED_MIN_ALIGN (1u << JIT_SMALL_SEGREGATED_MIN_ALIGN_SHIFT)
 #define JIT_SMALL_BITFIT_MIN_ALIGN_SHIFT 2u
 #define JIT_SMALL_BITFIT_MIN_ALIGN (1u << JIT_SMALL_BITFIT_MIN_ALIGN_SHIFT)
+#if PAS_ARM64 && PAS_OS(LINUX)
+#define JIT_SMALL_PAGE_SIZE 65536u
+#define JIT_SMALL_GRANULE_SIZE 65536u
+#else
 #define JIT_SMALL_PAGE_SIZE 16384u
 #define JIT_SMALL_GRANULE_SIZE 16384u
+#endif
 #define JIT_MEDIUM_BITFIT_MIN_ALIGN_SHIFT 8u
 #define JIT_MEDIUM_BITFIT_MIN_ALIGN (1u << JIT_MEDIUM_BITFIT_MIN_ALIGN_SHIFT)
+#if PAS_ARM64 && PAS_OS(LINUX)
+#define JIT_MEDIUM_PAGE_SIZE 262144u
+#define JIT_MEDIUM_GRANULE_SIZE 65536u
+#else
 #define JIT_MEDIUM_PAGE_SIZE 131072u
 #if PAS_ARM64
 #define JIT_MEDIUM_GRANULE_SIZE 16384u
 #else
 #define JIT_MEDIUM_GRANULE_SIZE 4096u
 #endif
+#endif
 
 PAS_API void jit_heap_config_activate(void);
 
diff --git a/Source/bmalloc/libpas/src/libpas/pas_expendable_memory.h b/Source/bmalloc/libpas/src/libpas/pas_expendable_memory.h
index 737fe9574e0f..5b7418a6d3b6 100644
--- a/Source/bmalloc/libpas/src/libpas/pas_expendable_memory.h
+++ b/Source/bmalloc/libpas/src/libpas/pas_expendable_memory.h
@@ -51,7 +51,11 @@ struct pas_expendable_memory {
     pas_expendable_memory_state states[1];
 };
 
+#if PAS_ARM64 && PAS_OS(LINUX)
+#define PAS_EXPENDABLE_MEMORY_PAGE_SIZE 65536llu
+#else
 #define PAS_EXPENDABLE_MEMORY_PAGE_SIZE 16384llu
+#endif
 
 PAS_API extern pas_expendable_memory_state_version pas_expendable_memory_version_counter;
 
diff --git a/Source/bmalloc/libpas/src/libpas/pas_internal_config.h b/Source/bmalloc/libpas/src/libpas/pas_internal_config.h
index f8fbb1734d23..16a63b28516f 100644
--- a/Source/bmalloc/libpas/src/libpas/pas_internal_config.h
+++ b/Source/bmalloc/libpas/src/libpas/pas_internal_config.h
@@ -35,22 +35,43 @@
 #define PAS_USE_MARGE_BITFIT_OVERRIDE         true
 
 /* The OS may have a smaller page size. That's OK. */
+/* On Linux ARM64, kernels may be configured with 64 KiB pages (e.g. RHEL, Oracle Linux).
+   All page and granule sizes must be at least as large as the system page size, so use
+   64 KiB minimums on Linux ARM64 to support all possible kernel page configurations. */
+#if PAS_ARM64 && PAS_OS(LINUX)
+#define PAS_SMALL_PAGE_DEFAULT_SHIFT     16
+#else
 #define PAS_SMALL_PAGE_DEFAULT_SHIFT     14
+#endif
 #define PAS_SMALL_PAGE_DEFAULT_SIZE      ((size_t)1 << PAS_SMALL_PAGE_DEFAULT_SHIFT)
 
+#if PAS_ARM64 && PAS_OS(LINUX)
+#define PAS_SMALL_BITFIT_PAGE_DEFAULT_SHIFT   16
+#else
 #define PAS_SMALL_BITFIT_PAGE_DEFAULT_SHIFT   14
+#endif
 #define PAS_SMALL_BITFIT_PAGE_DEFAULT_SIZE    ((size_t)1 << PAS_SMALL_BITFIT_PAGE_DEFAULT_SHIFT)
 
+#if PAS_ARM64 && PAS_OS(LINUX)
+#define PAS_MEDIUM_PAGE_DEFAULT_SHIFT    18
+#else
 #define PAS_MEDIUM_PAGE_DEFAULT_SHIFT    17
+#endif
 #define PAS_MEDIUM_PAGE_DEFAULT_SIZE     ((size_t)1 << PAS_MEDIUM_PAGE_DEFAULT_SHIFT)
 
+#if PAS_ARM64 && PAS_OS(LINUX)
+#define PAS_MEDIUM_BITFIT_PAGE_DEFAULT_SHIFT    19
+#else
 #define PAS_MEDIUM_BITFIT_PAGE_DEFAULT_SHIFT    19
+#endif
 #define PAS_MEDIUM_BITFIT_PAGE_DEFAULT_SIZE     ((size_t)1 << PAS_MEDIUM_BITFIT_PAGE_DEFAULT_SHIFT)
 
 #define PAS_MARGE_PAGE_DEFAULT_SHIFT     22
 #define PAS_MARGE_PAGE_DEFAULT_SIZE      ((size_t)1 << PAS_MARGE_PAGE_DEFAULT_SHIFT)
 
-#if PAS_ARM64 || PAS_PLATFORM(PLAYSTATION)
+#if PAS_ARM64 && PAS_OS(LINUX)
+#define PAS_GRANULE_DEFAULT_SHIFT        16
+#elif PAS_ARM64 || PAS_PLATFORM(PLAYSTATION)
 #define PAS_GRANULE_DEFAULT_SHIFT        14
 #else
 #define PAS_GRANULE_DEFAULT_SHIFT        12
@@ -131,7 +152,9 @@
 
 #define PAS_NUM_BASELINE_ALLOCATORS      32u
 
-#define PAS_MAX_OBJECTS_PER_PAGE         2048
+/* Must be >= max(page_size >> min_align_shift) across all segregated configs.
+   Utility heap uses PAS_INTERNAL_MIN_ALIGN_SHIFT (3) with the small page. */
+#define PAS_MAX_OBJECTS_PER_PAGE         (PAS_SMALL_PAGE_DEFAULT_SIZE >> PAS_INTERNAL_MIN_ALIGN_SHIFT)
 
 #define PAS_MPROTECT_DECOMMITTED         PAS_ENABLE_TESTING