[fireball] 32463: - Save original value of the free descriptor we're using to alloc early pages from. - Fix handling of PFN database pages inside PFN: largest free descriptor does not always end with the highest usable physical page (MmPageArraySize). This removes the need for a "good hack" introduced in revision 32405. As a result, the memory above the largest free descriptor (if it exists) is now correctly marked in the PFN database as free and added to the unzeroed list.

Author: fireball
Date: Sun Feb 24 13:43:56 2008
New Revision: 32463

URL: http://svn.reactos.org/svn/reactos?rev=32463&view=rev
Log:
- Save original value of the free descriptor we're using to alloc early pages from.
- Fix handling of PFN database pages inside PFN: largest free descriptor does not always
end with the highest usable physical page (MmPageArraySize). This removes the need for a
"good hack" introduced in revision 32405. As a result, the memory above the
largest free descriptor (if it exists) is now correctly marked in the PFN database as free
and added to the unzeroed list.

Modified:
    trunk/reactos/ntoskrnl/include/internal/mm.h
    trunk/reactos/ntoskrnl/mm/freelist.c
    trunk/reactos/ntoskrnl/mm/mminit.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 (original)
+++ trunk/reactos/ntoskrnl/include/internal/mm.h Sun Feb 24 13:43:56 2008
@@ -19,6 +19,7 @@
 extern ULONG MmPagedPoolSize;
 
 extern PMEMORY_ALLOCATION_DESCRIPTOR MiFreeDescriptor;
+extern MEMORY_ALLOCATION_DESCRIPTOR MiFreeDescriptorOrg;
 extern ULONG MmHighestPhysicalPage;
 extern PVOID MmPfnDatabase;
 

Modified: trunk/reactos/ntoskrnl/mm/freelist.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/freelist.c?rev…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/freelist.c (original)
+++ trunk/reactos/ntoskrnl/mm/freelist.c Sun Feb 24 13:43:56 2008
@@ -54,13 +54,13 @@
 
     /* Make sure the PFN number is valid */
     ASSERT(Pfn <= MmPageArraySize);
-    
+
     /* Get the entry */
     Page = &MmPageArray[Pfn];
-    
+
     /* Make sure it's valid */
     ASSERT_PFN(Page);
-    
+
     /* Return it */
     return Page;
 }
@@ -368,20 +368,14 @@
             }
         }
     }
-    
+
     /* Finally handle the pages describing the PFN database themselves */
     for (i = (MiFreeDescriptor->BasePage + MiFreeDescriptor->PageCount);
-         i <= MmPageArraySize;
+         i < (MiFreeDescriptorOrg.BasePage + MiFreeDescriptorOrg.PageCount);
          i++)
     {
-        /* If this page was marked as free it should be removed from
-           the unzeroed free pages list */
-        if (MmPageArray[i].Flags.Type == MM_PHYSICAL_PAGE_FREE)
-        {
-            RemoveEntryList(&MmPageArray[i].ListEntry);
-            UnzeroedPageCount--;
-            MmStats.NrFreePages--;
-        }
+        /* Ensure this page was not added previously */
+        ASSERT(MmPageArray[i].Flags.Type == 0);
 
         /* Mark it as used kernel memory */
         MmPageArray[i] = UsedPage;
@@ -764,7 +758,7 @@
              MiZeroPage(PfnOffset);
              return PfnOffset;
          }
-          
+
          DPRINT1("MmAllocPage(): Out of memory\n");
          KeReleaseSpinLock(&PageListLock, oldIrql);
          return 0;

Modified: trunk/reactos/ntoskrnl/mm/mminit.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/mminit.c?rev=3…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/mminit.c (original)
+++ trunk/reactos/ntoskrnl/mm/mminit.c Sun Feb 24 13:43:56 2008
@@ -55,6 +55,7 @@
 PVOID MmPfnDatabase;
 ULONG_PTR MmPfnDatabaseEnd;
 PMEMORY_ALLOCATION_DESCRIPTOR MiFreeDescriptor;
+MEMORY_ALLOCATION_DESCRIPTOR MiFreeDescriptorOrg;
 extern KMUTANT MmSystemLoadLock;
 BOOLEAN MiDbgEnableMdDump =
 #ifdef _ARM_
@@ -246,6 +247,10 @@
             }
         }
     }
+
+    /* Save original values of the free descriptor, since it'll be
+       altered by early allocations */
+    MiFreeDescriptorOrg = *MiFreeDescriptor;
 }
 
 VOID