Index: subsys/win32k/ntuser/guicheck.c
===================================================================
--- subsys/win32k/ntuser/guicheck.c	(revision 13570)
+++ subsys/win32k/ntuser/guicheck.c	(working copy)
@@ -41,7 +41,6 @@
 /* GLOBALS *******************************************************************/
 
 static LONG NrGuiAppsRunning = 0;
-static FAST_MUTEX GuiSwitchLock;
 
 /* FUNCTIONS *****************************************************************/
 
@@ -53,9 +52,7 @@
     {
       BOOL Initialized;
       
-      ExAcquireFastMutex(&GuiSwitchLock);
       Initialized = IntInitializeDesktopGraphics();
-      ExReleaseFastMutex(&GuiSwitchLock);
       
       if (!Initialized)
         {
@@ -73,9 +70,7 @@
   W32Data->Flags &= ~W32PF_CREATEDWINORDC;
   if (InterlockedDecrement(&NrGuiAppsRunning) == 0)
     {
-      ExAcquireFastMutex(&GuiSwitchLock);
       IntEndDesktopGraphics();
-      ExReleaseFastMutex(&GuiSwitchLock);
     }
 }
 
@@ -132,7 +127,6 @@
 NTSTATUS FASTCALL
 InitGuiCheckImpl (VOID)
 {
-  ExInitializeFastMutex(&GuiSwitchLock);
   return STATUS_SUCCESS;
 }
 
Index: subsys/win32k/include/msgqueue.h
===================================================================
--- subsys/win32k/include/msgqueue.h	(revision 13570)
+++ subsys/win32k/include/msgqueue.h	(working copy)
@@ -218,10 +218,10 @@
 VOID STDCALL MsqRemoveWindowMessagesFromQueue(PVOID pWindow); /* F*(&$ headers, will be gone in the rewrite! */
 
 #define IntLockMessageQueue(MsgQueue) \
-  ExAcquireFastMutex(&(MsgQueue)->Lock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&(MsgQueue)->Lock)
 
 #define IntUnLockMessageQueue(MsgQueue) \
-  ExReleaseFastMutex(&(MsgQueue)->Lock)
+  ExReleaseFastMutexUnsafe(&(MsgQueue)->Lock), KeLeaveCriticalRegion()
 
 #define IntLockHardwareMessageQueue(MsgQueue) \
   KeWaitForMutexObject(&(MsgQueue)->HardwareLock, UserRequest, KernelMode, FALSE, NULL)
Index: subsys/win32k/include/hotkey.h
===================================================================
--- subsys/win32k/include/hotkey.h	(revision 13570)
+++ subsys/win32k/include/hotkey.h	(working copy)
@@ -37,10 +37,10 @@
 UnregisterThreadHotKeys(struct _ETHREAD *Thread);
 
 #define IntLockHotKeys(WinStaObject) \
-  ExAcquireFastMutex(&WinStaObject->HotKeyListLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&WinStaObject->HotKeyListLock)
 
 #define IntUnLockHotKeys(WinStaObject) \
-  ExReleaseFastMutex(&WinStaObject->HotKeyListLock)
+  ExReleaseFastMutexUnsafe(&WinStaObject->HotKeyListLock), KeLeaveCriticalRegion()
 
 #endif /* _WIN32K_HOTKEY_H */
 
Index: subsys/win32k/include/class.h
===================================================================
--- subsys/win32k/include/class.h	(revision 13570)
+++ subsys/win32k/include/class.h	(working copy)
@@ -40,16 +40,16 @@
 CleanupClassImpl(VOID);
 
 #define IntLockProcessClasses(W32Process) \
-  ExAcquireFastMutex(&(W32Process)->ClassListLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&(W32Process)->ClassListLock)
 
 #define IntUnLockProcessClasses(W32Process) \
-  ExReleaseFastMutex(&(W32Process)->ClassListLock)
+  ExReleaseFastMutexUnsafe(&(W32Process)->ClassListLock), KeLeaveCriticalRegion()
 
 #define IntLockClassWindows(ClassObj) \
-  ExAcquireFastMutex(&(ClassObj)->ClassWindowsListLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&(ClassObj)->ClassWindowsListLock)
 
 #define IntUnLockClassWindows(ClassObj) \
-  ExReleaseFastMutex(&(ClassObj)->ClassWindowsListLock)
+  ExReleaseFastMutexUnsafe(&(ClassObj)->ClassWindowsListLock), KeLeaveCriticalRegion()
 
 #define ClassDereferenceObject(ClassObj) \
   ObmDereferenceObject(ClassObj)
Index: subsys/win32k/include/object.h
===================================================================
--- subsys/win32k/include/object.h	(revision 13570)
+++ subsys/win32k/include/object.h	(working copy)
@@ -49,10 +49,10 @@
 
 
 #define ObmpLockHandleTable(HandleTable) \
-  ExAcquireFastMutex(&HandleTable->ListLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&HandleTable->ListLock)
 
 #define ObmpUnlockHandleTable(HandleTable) \
-  ExReleaseFastMutex(&HandleTable->ListLock)
+  ExReleaseFastMutexUnsafe(&HandleTable->ListLock), KeLeaveCriticalRegion()
 
 ULONG FASTCALL
 ObmGetReferenceCount(
Index: subsys/win32k/include/painting.h
===================================================================
--- subsys/win32k/include/painting.h	(revision 13570)
+++ subsys/win32k/include/painting.h	(working copy)
@@ -18,9 +18,9 @@
 NtUserValidateRgn(HWND hWnd, HRGN hRgn);
 
 #define IntLockWindowUpdate(Window) \
-  ExAcquireFastMutex(&Window->UpdateLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&Window->UpdateLock)
 
 #define IntUnLockWindowUpdate(Window) \
-  ExReleaseFastMutex(&Window->UpdateLock)
+  ExReleaseFastMutexUnsafe(&Window->UpdateLock), KeLeaveCriticalRegion()
 
 #endif /* _WIN32K_PAINTING_H */
Index: subsys/win32k/include/text.h
===================================================================
--- subsys/win32k/include/text.h	(revision 13570)
+++ subsys/win32k/include/text.h	(working copy)
@@ -8,21 +8,21 @@
 INT FASTCALL FontGetObject(PTEXTOBJ TextObj, INT Count, PVOID Buffer);
 
 #define IntLockProcessPrivateFonts(W32Process) \
-  ExAcquireFastMutex(&W32Process->PrivateFontListLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&W32Process->PrivateFontListLock)
 
 #define IntUnLockProcessPrivateFonts(W32Process) \
-  ExReleaseFastMutex(&W32Process->PrivateFontListLock)
+  ExReleaseFastMutexUnsafe(&W32Process->PrivateFontListLock), KeLeaveCriticalRegion()
 
 #define IntLockGlobalFonts \
-  ExAcquireFastMutex(&FontListLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&FontListLock)
 
 #define IntUnLockGlobalFonts \
-  ExReleaseFastMutex(&FontListLock)
+  ExReleaseFastMutexUnsafe(&FontListLock), KeLeaveCriticalRegion()
 
 #define IntLockFreeType \
-  ExAcquireFastMutex(&FreeTypeLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&FreeTypeLock)
 
 #define IntUnLockFreeType \
-  ExReleaseFastMutex(&FreeTypeLock)
+  ExReleaseFastMutexUnsafe(&FreeTypeLock), KeLeaveCriticalRegion()
 
 #endif /* _WIN32K_TEXT_H */
Index: subsys/win32k/include/cursoricon.h
===================================================================
--- subsys/win32k/include/cursoricon.h	(revision 13570)
+++ subsys/win32k/include/cursoricon.h	(working copy)
@@ -65,10 +65,10 @@
   ObmDereferenceObject(CurIconObj)
 
 #define IntLockProcessCursorIcons(W32Process) \
-  ExAcquireFastMutex(&W32Process->CursorIconListLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&W32Process->CursorIconListLock)
 
 #define IntUnLockProcessCursorIcons(W32Process) \
-  ExReleaseFastMutex(&W32Process->CursorIconListLock)
+  ExReleaseFastMutexUnsafe(&W32Process->CursorIconListLock), KeLeaveCriticalRegion()
 
 #endif /* _WIN32K_CURSORICON_H */
 
Index: subsys/win32k/include/hook.h
===================================================================
--- subsys/win32k/include/hook.h	(revision 13570)
+++ subsys/win32k/include/hook.h	(working copy)
@@ -31,10 +31,10 @@
 VOID FASTCALL HOOK_DestroyThreadHooks(PETHREAD Thread);
 
 #define IntLockHookTable(HookTable) \
-  ExAcquireFastMutex(&HookTable->Lock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&HookTable->Lock)
 
 #define IntUnLockHookTable(HookTable) \
-  ExReleaseFastMutex(&HookTable->Lock)
+  ExReleaseFastMutexUnsafe(&HookTable->Lock), KeLeaveCriticalRegion()
 
 #endif /* _WIN32K_HOOK_H */
 
Index: subsys/win32k/include/menu.h
===================================================================
--- subsys/win32k/include/menu.h	(revision 13570)
+++ subsys/win32k/include/menu.h	(working copy)
@@ -45,16 +45,16 @@
 IntGetMenuObject(HMENU hMenu);
 
 #define IntLockMenuItems(MenuObj) \
-  ExAcquireFastMutex(&(MenuObj)->MenuItemsLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&(MenuObj)->MenuItemsLock)
 
 #define IntUnLockMenuItems(MenuObj) \
-  ExReleaseFastMutex(&(MenuObj)->MenuItemsLock)
+  ExReleaseFastMutexUnsafe(&(MenuObj)->MenuItemsLock), KeLeaveCriticalRegion()
 
 #define IntLockProcessMenus(W32Process) \
-  ExAcquireFastMutex(&(W32Process)->MenuListLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&(W32Process)->MenuListLock)
 
 #define IntUnLockProcessMenus(W32Process) \
-  ExReleaseFastMutex(&(W32Process)->MenuListLock)
+  ExReleaseFastMutexUnsafe(&(W32Process)->MenuListLock), KeLeaveCriticalRegion()
 
 #define IntReleaseMenuObject(MenuObj) \
   ObmDereferenceObject(MenuObj)
Index: subsys/win32k/include/window.h
===================================================================
--- subsys/win32k/include/window.h	(revision 13570)
+++ subsys/win32k/include/window.h	(working copy)
@@ -148,16 +148,16 @@
   WndObj->OwnerThread->ThreadsProcess->UniqueProcessId
 
 #define IntLockRelatives(WndObj) \
-  ExAcquireFastMutex(&WndObj->RelativesLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&WndObj->RelativesLock)
 
 #define IntUnLockRelatives(WndObj) \
-  ExReleaseFastMutex(&WndObj->RelativesLock)
+  ExReleaseFastMutexUnsafe(&WndObj->RelativesLock), KeLeaveCriticalRegion()
 
 #define IntLockThreadWindows(Thread) \
-  ExAcquireFastMutex(&Thread->WindowListLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&Thread->WindowListLock)
 
 #define IntUnLockThreadWindows(Thread) \
-  ExReleaseFastMutex(&Thread->WindowListLock)
+  ExReleaseFastMutexUnsafe(&Thread->WindowListLock), KeLeaveCriticalRegion()
 
 
 PWINDOW_OBJECT FASTCALL
Index: subsys/win32k/include/prop.h
===================================================================
--- subsys/win32k/include/prop.h	(revision 13570)
+++ subsys/win32k/include/prop.h	(working copy)
@@ -15,10 +15,10 @@
 IntGetProp(PWINDOW_OBJECT WindowObject, ATOM Atom);
 
 #define IntLockWindowProperties(Window) \
-  ExAcquireFastMutex(&Window->PropListLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&Window->PropListLock)
 
 #define IntUnLockWindowProperties(Window) \
-  ExReleaseFastMutex(&Window->PropListLock)
+  ExReleaseFastMutexUnsafe(&Window->PropListLock), KeLeaveCriticalRegion()
 
 #endif /* _WIN32K_PROP_H */
 
Index: subsys/win32k/include/inteng.h
===================================================================
--- subsys/win32k/include/inteng.h	(revision 13570)
+++ subsys/win32k/include/inteng.h	(working copy)
@@ -33,10 +33,10 @@
 /* Definitions of IntEngXxx functions */
 
 #define IntEngLockProcessDriverObjs(W32Process) \
-  ExAcquireFastMutex(&(W32Process)->DriverObjListLock)
+  KeEnterCriticalRegion(), ExAcquireFastMutexUnsafe(&(W32Process)->DriverObjListLock)
 
 #define IntEngUnLockProcessDriverObjs(W32Process) \
-  ExReleaseFastMutex(&(W32Process)->DriverObjListLock)
+  ExReleaseFastMutexUnsafe(&(W32Process)->DriverObjListLock), KeLeaveCriticalRegion()
 
 VOID FASTCALL
 IntEngCleanupDriverObjs(struct _EPROCESS *Process,
Index: hal/halx86/generic/fmutex.c
===================================================================
--- hal/halx86/generic/fmutex.c	(revision 13570)
+++ hal/halx86/generic/fmutex.c	(working copy)
@@ -21,33 +21,33 @@
 VOID FASTCALL
 ExAcquireFastMutex (PFAST_MUTEX	FastMutex)
 {
-   KeEnterCriticalRegion();
+   KIRQL OldIrql = KfRaiseIrql(APC_LEVEL);
    ExAcquireFastMutexUnsafe(FastMutex);
+   FastMutex->OldIrql = OldIrql;
 }
 
 
 VOID FASTCALL
 ExReleaseFastMutex (PFAST_MUTEX	FastMutex)
 {
-  ExReleaseFastMutexUnsafe(FastMutex);
-  KeLeaveCriticalRegion();
+   KIRQL OldIrql = FastMutex->OldIrql;
+   ExReleaseFastMutexUnsafe(FastMutex);
+   KfLowerIrql(OldIrql);
 }
 
 
 BOOLEAN FASTCALL
 ExTryToAcquireFastMutex (PFAST_MUTEX FastMutex)
 {
-  KeEnterCriticalRegion();
-  if (InterlockedExchange(&FastMutex->Count, 0) == 1)
-    {
+   KIRQL OldIrql = KfRaiseIrql(APC_LEVEL);
+   if (InterlockedCompareExchange(&FastMutex->Count, 0, 1) == 1)
+   {
       FastMutex->Owner = KeGetCurrentThread();
-      return(TRUE);
-    }
-  else
-    {
-      KeLeaveCriticalRegion();
-      return(FALSE);
-    }
+      FastMutex->OldIrql = OldIrql;
+      return TRUE;
+   }
+   KfLowerIrql(OldIrql);
+   return FALSE;
 }
 
 /* EOF */
Index: hal/halx86/generic/adapter.c
===================================================================
--- hal/halx86/generic/adapter.c	(revision 13570)
+++ hal/halx86/generic/adapter.c	(working copy)
@@ -85,6 +85,7 @@
    * buffer transfers. See a comment in IoMapTransfer about common buffer
    * support.
    */
+#if 0
   AdapterObject->MapRegisterBase = MmAllocateContiguousAlignedMemory( 
       NumberOfMapRegisters * PAGE_SIZE,
       MinAddress,
@@ -92,6 +93,7 @@
       BoundryAddressMultiple,
       MmCached,
       0x10000 );
+#endif
 
   if(!AdapterObject->MapRegisterBase)
     return STATUS_INSUFFICIENT_RESOURCES;
Index: ntoskrnl/ps/create.c
===================================================================
--- ntoskrnl/ps/create.c	(revision 13570)
+++ ntoskrnl/ps/create.c	(working copy)
@@ -524,7 +524,8 @@
    else
      {
        Process = Thread->ThreadsProcess;
-       ExAcquireFastMutex(&Process->TebLock);
+       KeEnterCriticalRegion();
+       ExAcquireFastMutexUnsafe(&Process->TebLock);
        if (NULL == Process->TebBlock ||
            Process->TebBlock == Process->TebLastAllocated)
          {
@@ -538,7 +539,8 @@
                                             PAGE_READWRITE);
            if (! NT_SUCCESS(Status))
              {
-               ExReleaseFastMutex(&Process->TebLock);
+               ExReleaseFastMutexUnsafe(&Process->TebLock);
+               KeLeaveCriticalRegion();
                DPRINT1("Failed to reserve virtual memory for TEB\n");
                return Status;
              }
@@ -557,7 +559,8 @@
            return Status;
          }
        Process->TebLastAllocated = TebBase;
-       ExReleaseFastMutex(&Process->TebLock);
+       ExReleaseFastMutexUnsafe(&Process->TebLock);
+       KeLeaveCriticalRegion();
      }
 
    DPRINT ("TebBase %p TebSize %lu\n", TebBase, TebSize);
Index: ntoskrnl/ps/kill.c
===================================================================
--- ntoskrnl/ps/kill.c	(revision 13570)
+++ ntoskrnl/ps/kill.c	(working copy)
@@ -157,7 +157,8 @@
    if(CurrentThread->Tcb.Teb)
    {
      DPRINT("Decommit teb at %p\n", CurrentThread->Tcb.Teb);
-     ExAcquireFastMutex(&CurrentProcess->TebLock);
+     KeEnterCriticalRegion();
+     ExAcquireFastMutexUnsafe(&CurrentProcess->TebLock);
      TebBlock = MM_ROUND_DOWN(CurrentThread->Tcb.Teb, MM_VIRTMEM_GRANULARITY);
      ZwFreeVirtualMemory(NtCurrentProcess(),
                          (PVOID *)&CurrentThread->Tcb.Teb,
@@ -172,7 +173,8 @@
          MmUnlockAddressSpace(&CurrentProcess->AddressSpace);
        }
      CurrentThread->Tcb.Teb = NULL;
-     ExReleaseFastMutex(&CurrentProcess->TebLock);
+     ExReleaseFastMutexUnsafe(&CurrentProcess->TebLock);
+     KeLeaveCriticalRegion();
    }
 
    /* abandon all owned mutants */
Index: ntoskrnl/ex/fmutex.c
===================================================================
--- ntoskrnl/ex/fmutex.c	(revision 13570)
+++ ntoskrnl/ex/fmutex.c	(working copy)
@@ -21,18 +21,14 @@
 VOID FASTCALL
 ExAcquireFastMutexUnsafe(PFAST_MUTEX FastMutex)
 {
-  ASSERT(FastMutex->Owner != KeGetCurrentThread());
-  InterlockedIncrementUL(&FastMutex->Contention);
-  while (InterlockedExchange(&FastMutex->Count, 0) == 0)
-     {
-       KeWaitForSingleObject(&FastMutex->Event,
-			     Executive,
-			     KernelMode,
-			     FALSE,
-			     NULL);
-     }
-  InterlockedDecrementUL(&FastMutex->Contention);
-  FastMutex->Owner = KeGetCurrentThread();
+   ASSERT(FastMutex->Owner != KeGetCurrentThread());
+   if (InterlockedDecrement(&FastMutex->Count) != 0)
+   {
+      FastMutex->Contention++;
+      KeWaitForSingleObject(&FastMutex->Event, Executive, KernelMode,
+                            FALSE, NULL);
+   }
+   FastMutex->Owner = KeGetCurrentThread();
 }
 
 /*
@@ -41,13 +37,10 @@
 VOID FASTCALL
 ExReleaseFastMutexUnsafe(PFAST_MUTEX FastMutex)
 {
-  ASSERT(FastMutex->Owner == KeGetCurrentThread());
-  FastMutex->Owner = NULL;
-  InterlockedExchange(&FastMutex->Count, 1);
-  if (FastMutex->Contention > 0)
-    {
+   ASSERT(FastMutex->Owner == KeGetCurrentThread());
+   FastMutex->Owner = NULL;
+   if (InterlockedIncrement(&FastMutex->Count) <= 0)
       KeSetEvent(&FastMutex->Event, 0, FALSE);
-    }
 }
 
 /* EOF */