[ros-diffs] [fireball] 33092: - The address space lock is a pushlock -- pushlocks can fail if callers are acquiring them without first disabling APCs, so they should always be acquired within a critical region. Fix the address space lock to do this. - Don't keep track of the page table reference count table in the address space structure, nobody was using this. - Instead of using either a global kernel pushlock for the kernel address space, and a per-process lock for process address space, always use a per-

Author: fireball
Date: Mon Apr 21 16:42:00 2008
New Revision: 33092

URL: http://svn.reactos.org/svn/reactos?rev=33092&view=rev
Log:
- The address space lock is a pushlock -- pushlocks can fail if callers are acquiring them
without first disabling APCs, so they should always be acquired within a critical region.
Fix the address space lock to do this.
- Don't keep track of the page table reference count table in the address space
structure, nobody was using this.
- Instead of using either a global kernel pushlock for the kernel address space, and a
per-process lock for process address space, always use a per-process lock (the kernel
address space uses the idle process' lock).
- Instead of acquiring/releasing the lock by dereferencing the process which owns the
address space, hold a pointer to the lock directly. This removes an extra dereference, and
also allows the kernel lock to work (because kernel address space doesn't have an
associated process).
- Inline the lock acquisition/release functions and the get-address-space functions.
- Measured a 20% performance boost during boot-up, and 150% during installation.
- Patch by Alex.

Modified:
    trunk/reactos/ntoskrnl/include/internal/mm.h
    trunk/reactos/ntoskrnl/mm/aspace.c

Modified: trunk/reactos/ntoskrnl/include/internal/mm.h
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/include/internal/…
==============================================================================
--- trunk/reactos/ntoskrnl/include/internal/mm.h [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/include/internal/mm.h [iso-8859-1] Mon Apr 21 16:42:00 2008
@@ -254,9 +254,9 @@
 {
     PMEMORY_AREA MemoryAreaRoot;
     PVOID LowestAddress;
-    struct _EPROCESS* Process;
+    PEPROCESS Process;
     PUSHORT PageTableRefCountTable;
-    ULONG PageTableRefCountTableSize;
+    PEX_PUSH_LOCK Lock;
 } MADDRESS_SPACE, *PMADDRESS_SPACE;
 
 typedef struct
@@ -394,23 +394,7 @@
 
 VOID
 NTAPI
-MmLockAddressSpace(PMADDRESS_SPACE AddressSpace);
-
-VOID
-NTAPI
-MmUnlockAddressSpace(PMADDRESS_SPACE AddressSpace);
-
-VOID
-NTAPI
 MmInitializeKernelAddressSpace(VOID);
-
-PMADDRESS_SPACE
-NTAPI
-MmGetCurrentAddressSpace(VOID);
-
-PMADDRESS_SPACE
-NTAPI
-MmGetKernelAddressSpace(VOID);
 
 NTSTATUS
 NTAPI
@@ -1584,4 +1568,37 @@
     MmUpdatePageDir((PEPROCESS)Process, Address, Size);
 }
 
+
+extern MADDRESS_SPACE MmKernelAddressSpace;
+
+FORCEINLINE
+VOID
+MmLockAddressSpace(PMADDRESS_SPACE AddressSpace)
+{
+    KeEnterCriticalRegion();
+    ExAcquirePushLockExclusive(AddressSpace->Lock);
+}
+
+FORCEINLINE
+VOID
+MmUnlockAddressSpace(PMADDRESS_SPACE AddressSpace)
+{
+    ExReleasePushLock(AddressSpace->Lock);
+    KeLeaveCriticalRegion();
+}
+
+FORCEINLINE
+PMADDRESS_SPACE
+MmGetCurrentAddressSpace(VOID)
+{
+    return
(PMADDRESS_SPACE)&((PEPROCESS)KeGetCurrentThread()->ApcState.Process)->VadRoot;
+}
+
+FORCEINLINE
+PMADDRESS_SPACE
+MmGetKernelAddressSpace(VOID)
+{
+    return &MmKernelAddressSpace;
+}
+
 #endif

Modified: trunk/reactos/ntoskrnl/mm/aspace.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/aspace.c?rev=3…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/aspace.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/aspace.c [iso-8859-1] Mon Apr 21 16:42:00 2008
@@ -19,59 +19,19 @@
 
 /* GLOBALS ******************************************************************/
 
-static MADDRESS_SPACE KernelAddressSpace;
-EX_PUSH_LOCK KernelAddressSpaceLock;
+MADDRESS_SPACE MmKernelAddressSpace;
+
+ULONGLONG Cycles;
+ULONG TimeDelta;
 
 /* FUNCTIONS *****************************************************************/
-
-VOID
-NTAPI
-MmLockAddressSpace(PMADDRESS_SPACE AddressSpace)
-{
-   if (AddressSpace->Process)
-   {
-      
ExAcquirePushLockExclusive((PEX_PUSH_LOCK)&AddressSpace->Process->AddressCreationLock);
-   }
-   else
-   {
-       ExAcquirePushLockExclusive(&KernelAddressSpaceLock);
-   }
-}
-
-VOID
-NTAPI
-MmUnlockAddressSpace(PMADDRESS_SPACE AddressSpace)
-{
-   if (AddressSpace->Process)
-   {
-       
ExReleasePushLock((PEX_PUSH_LOCK)&AddressSpace->Process->AddressCreationLock);
-   }
-   else
-   {
-        ExReleasePushLock(&KernelAddressSpaceLock);
-   }
-}
 
 VOID
 INIT_FUNCTION
 NTAPI
 MmInitializeKernelAddressSpace(VOID)
 {
-   MmInitializeAddressSpace(NULL, &KernelAddressSpace);
-}
-
-PMADDRESS_SPACE
-NTAPI
-MmGetCurrentAddressSpace(VOID)
-{
-   return((PMADDRESS_SPACE)&(PsGetCurrentProcess())->VadRoot);
-}
-
-PMADDRESS_SPACE
-NTAPI
-MmGetKernelAddressSpace(VOID)
-{
-   return(&KernelAddressSpace);
+    MmInitializeAddressSpace(NULL, &MmKernelAddressSpace);
 }
 
 NTSTATUS
@@ -79,51 +39,45 @@
 MmInitializeAddressSpace(PEPROCESS Process,
                          PMADDRESS_SPACE AddressSpace)
 {
-   AddressSpace->MemoryAreaRoot = NULL;
-   if (Process)
-   {
-       ExInitializePushLock((PULONG_PTR)&Process->AddressCreationLock);
-   }
-   else
-   {
-        ExInitializePushLock((PULONG_PTR)&KernelAddressSpaceLock);
-   }
-   if (Process != NULL)
-   {
-      AddressSpace->LowestAddress = MM_LOWEST_USER_ADDRESS;
-   }
-   else
-   {
-      AddressSpace->LowestAddress = MmSystemRangeStart;
-   }
-   AddressSpace->Process = Process;
-   if (Process != NULL)
-   {
-      ULONG Count;
-      Count = MiGetUserPageDirectoryCount();
-      AddressSpace->PageTableRefCountTable =
-         ExAllocatePoolWithTag(NonPagedPool, Count * sizeof(USHORT),
-                               TAG_PTRC);
-      RtlZeroMemory(AddressSpace->PageTableRefCountTable, Count * sizeof(USHORT));
-      AddressSpace->PageTableRefCountTableSize = Count;
-   }
-   else
-   {
-      AddressSpace->PageTableRefCountTable = NULL;
-      AddressSpace->PageTableRefCountTableSize = 0;
-   }
-   return(STATUS_SUCCESS);
+    ULONG Count;
+    
+    AddressSpace->MemoryAreaRoot = NULL;
+
+    if (Process != NULL)
+    {
+        AddressSpace->LowestAddress = MM_LOWEST_USER_ADDRESS;
+        AddressSpace->Process = Process;
+        AddressSpace->Lock = (PEX_PUSH_LOCK)&Process->AddressCreationLock;
+        ExInitializePushLock((PULONG_PTR)AddressSpace->Lock);
+        Count = MiGetUserPageDirectoryCount();
+        AddressSpace->PageTableRefCountTable = ExAllocatePoolWithTag(NonPagedPool,
+                                                                     Count *
sizeof(USHORT),
+                                                                     TAG_PTRC);
+        RtlZeroMemory(AddressSpace->PageTableRefCountTable, Count * sizeof(USHORT));
+        
+    }
+    else
+    {
+        AddressSpace->LowestAddress = MmSystemRangeStart;
+        AddressSpace->Process = NULL;
+        AddressSpace->PageTableRefCountTable = NULL;
+        AddressSpace->Lock =
(PEX_PUSH_LOCK)&PsGetCurrentProcess()->AddressCreationLock;
+        ExInitializePushLock((PULONG_PTR)AddressSpace->Lock);
+    }
+    
+    return STATUS_SUCCESS;
 }
 
 NTSTATUS
 NTAPI
 MmDestroyAddressSpace(PMADDRESS_SPACE AddressSpace)
 {
-   if (AddressSpace->PageTableRefCountTable != NULL)
-   {
-      ExFreePool(AddressSpace->PageTableRefCountTable);
-   }
-   return(STATUS_SUCCESS);
+    if (AddressSpace->PageTableRefCountTable)
+    {
+        ExFreePool(AddressSpace->PageTableRefCountTable);
+    }
+    
+    return STATUS_SUCCESS;
 }
 
 /* EOF */