From c67173fe362781d71c59d304a3b6cf9ba25409ae Mon Sep 17 00:00:00 2001
From: Ben Vanik <ben.vanik@gmail.com>
Date: Wed, 29 Jul 2015 20:28:06 -0700
Subject: [PATCH] Switching to real page sizes, not allocation granularity.

---
 src/xenia/base/memory.h       |  5 +++++
 src/xenia/base/memory_win.cc  | 10 ++++++++++
 src/xenia/cpu/thread_state.cc |  3 +--
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/xenia/base/memory.h b/src/xenia/base/memory.h
index ee29359db..e24dd0d94 100644
--- a/src/xenia/base/memory.h
+++ b/src/xenia/base/memory.h
@@ -21,8 +21,13 @@ namespace xe {
 namespace memory {
 
 // Returns the native page size of the system, in bytes.
+// This should be ~4KiB.
 size_t page_size();
 
+// Returns the allocation granularity of the system, in bytes.
+// This is likely 64KiB.
+size_t allocation_granularity();
+
 enum class PageAccess {
   kNoAccess = 0,
   kReadOnly = 1 << 0,
diff --git a/src/xenia/base/memory_win.cc b/src/xenia/base/memory_win.cc
index b2d6c96a1..27bcfb152 100644
--- a/src/xenia/base/memory_win.cc
+++ b/src/xenia/base/memory_win.cc
@@ -15,6 +15,16 @@ namespace xe {
 namespace memory {
 
 size_t page_size() {
+  static size_t value = 0;
+  if (!value) {
+    SYSTEM_INFO si;
+    GetSystemInfo(&si);
+    value = si.dwPageSize;
+  }
+  return value;
+}
+
+size_t allocation_granularity() {
   static size_t value = 0;
   if (!value) {
     SYSTEM_INFO si;
diff --git a/src/xenia/cpu/thread_state.cc b/src/xenia/cpu/thread_state.cc
index d0c1f3846..bf5932591 100644
--- a/src/xenia/cpu/thread_state.cc
+++ b/src/xenia/cpu/thread_state.cc
@@ -50,8 +50,7 @@ ThreadState::ThreadState(Processor* processor, uint32_t thread_id,
     // only Protect() on system page granularity.
     stack_size = (stack_size + 0xFFF) & 0xFFFFF000;
     uint32_t stack_alignment = (stack_size & 0xF000) ? 0x1000 : 0x10000;
-    uint32_t stack_padding =
-        uint32_t(xe::memory::page_size());  // Host page size.
+    uint32_t stack_padding = 64 * 1024;  // 0x4...0x7F is 64k.
     uint32_t actual_stack_size = stack_padding + stack_size;
     bool top_down = false;
     switch (stack_type) {