From e2d5ba4e1fff8251d3960af87be6f77e72672e7b Mon Sep 17 00:00:00 2001
From: Andrew Munger <waxdragon@gmail.com>
Date: Thu, 13 Mar 2008 15:26:17 +0000
Subject: [PATCH] Simplify and rename the functions that touch
 UserPageListHead. They were confusingly coded to accept any flavor of
 PFN_TYPE, which resulted in at least one bug. Constrained the calls to the
 MmRequest/ReleasePageMemoryConsumer and MmTrimUserMemory.

svn path=/trunk/; revision=32673
---
 reactos/ntoskrnl/include/internal/mm.h |  6 +++-
 reactos/ntoskrnl/mm/balance.c          |  7 ++++-
 reactos/ntoskrnl/mm/freelist.c         | 38 +++++++++++++-------------
 reactos/ntoskrnl/mm/wset.c             |  3 +-
 4 files changed, 32 insertions(+), 22 deletions(-)

diff --git a/reactos/ntoskrnl/include/internal/mm.h b/reactos/ntoskrnl/include/internal/mm.h
index 68a9d756809..99e8c7010d7 100644
--- a/reactos/ntoskrnl/include/internal/mm.h
+++ b/reactos/ntoskrnl/include/internal/mm.h
@@ -1025,7 +1025,11 @@ MmGetLRUFirstUserPage(VOID);
 
 VOID
 NTAPI
-MmSetLRULastPage(PFN_TYPE Page);
+MmInsertLRULastUserPage(PFN_TYPE Page);
+
+VOID
+NTAPI
+MmRemoveLRUUserPage(PFN_TYPE Page);
 
 VOID
 NTAPI
diff --git a/reactos/ntoskrnl/mm/balance.c b/reactos/ntoskrnl/mm/balance.c
index ed8e6cd95e3..7baf62930c0 100644
--- a/reactos/ntoskrnl/mm/balance.c
+++ b/reactos/ntoskrnl/mm/balance.c
@@ -114,6 +114,7 @@ MmReleasePageMemoryConsumer(ULONG Consumer, PFN_TYPE Page)
          Entry = RemoveHeadList(&AllocationListHead);
          Request = CONTAINING_RECORD(Entry, MM_ALLOCATION_REQUEST, ListEntry);
          KeReleaseSpinLock(&AllocationListLock, oldIrql);
+         if(Consumer == MC_USER) MmRemoveLRUUserPage(Page);
          Request->Page = Page;
          KeSetEvent(&Request->Event, IO_NO_INCREMENT, FALSE);
       }
@@ -121,6 +122,7 @@ MmReleasePageMemoryConsumer(ULONG Consumer, PFN_TYPE Page)
    else
    {
       KeReleaseSpinLock(&AllocationListLock, oldIrql);
+      if(Consumer == MC_USER) MmRemoveLRUUserPage(Page);
       MmDereferencePage(Page);
    }
 
@@ -262,7 +264,9 @@ MmRequestPageMemoryConsumer(ULONG Consumer, BOOLEAN CanWait,
       {
          KEBUGCHECK(NO_PAGES_AVAILABLE);
       }
-      MmSetLRULastPage(Page);
+      /* Update the Consumer */
+      MiGetPfnEntry(Page)->Flags.Consumer = Consumer;
+      if(Consumer == MC_USER) MmInsertLRULastUserPage(Page);
       *AllocatedPage = Page;
       (void)InterlockedDecrementUL(&MiPagesRequired);
       return(STATUS_SUCCESS);
@@ -276,6 +280,7 @@ MmRequestPageMemoryConsumer(ULONG Consumer, BOOLEAN CanWait,
    {
       KEBUGCHECK(NO_PAGES_AVAILABLE);
    }
+   if(Consumer == MC_USER) MmInsertLRULastUserPage(Page);
    *AllocatedPage = Page;
 
    return(STATUS_SUCCESS);
diff --git a/reactos/ntoskrnl/mm/freelist.c b/reactos/ntoskrnl/mm/freelist.c
index c0567fa21ce..ad84db26df1 100644
--- a/reactos/ntoskrnl/mm/freelist.c
+++ b/reactos/ntoskrnl/mm/freelist.c
@@ -31,8 +31,12 @@ PPHYSICAL_PAGE MmPageArray;
 ULONG MmPageArraySize;
 
 static KSPIN_LOCK PageListLock;
+/* List of pages allocated to the MC_USER Consumer */
 static LIST_ENTRY UserPageListHead;
+/* List of pages zeroed by the ZPW (MmZeroPageThreadMain) */
 static LIST_ENTRY FreeZeroedPageListHead;
+/* List of free pages, filled by MmGetReferenceCountPage and
+ * and MmInitializePageList */
 static LIST_ENTRY FreeUnzeroedPageListHead;
 
 static KEVENT ZeroPageThreadEvent;
@@ -65,19 +69,16 @@ MmGetLRUFirstUserPage(VOID)
 
 VOID
 NTAPI
-MmSetLRULastPage(PFN_TYPE Pfn)
+MmInsertLRULastUserPage(PFN_TYPE Pfn)
 {
    KIRQL oldIrql;
    PPHYSICAL_PAGE Page;
 
    KeAcquireSpinLock(&PageListLock, &oldIrql);
    Page = MiGetPfnEntry(Pfn);
-   if (Page->Flags.Type == MM_PHYSICAL_PAGE_USED &&
-       Page->Flags.Consumer == MC_USER)
-   {
-      RemoveEntryList(&Page->ListEntry);
-      InsertTailList(&UserPageListHead, &Page->ListEntry);
-   }
+   ASSERT(Page->Flags.Type == MM_PHYSICAL_PAGE_USED);
+   ASSERT(Page->Flags.Consumer == MC_USER);
+   InsertTailList(&UserPageListHead, &Page->ListEntry);
    KeReleaseSpinLock(&PageListLock, oldIrql);
 }
 
@@ -92,15 +93,9 @@ MmGetLRUNextUserPage(PFN_TYPE PreviousPfn)
 
    KeAcquireSpinLock(&PageListLock, &oldIrql);
    Page = MiGetPfnEntry(PreviousPfn);
-   if (Page->Flags.Type != MM_PHYSICAL_PAGE_USED ||
-       Page->Flags.Consumer != MC_USER)
-   {
-      NextListEntry = UserPageListHead.Flink;
-   }
-   else
-   {
-      NextListEntry = Page->ListEntry.Flink;
-   }
+   ASSERT(Page->Flags.Type == MM_PHYSICAL_PAGE_USED);
+   ASSERT(Page->Flags.Consumer == MC_USER);
+   NextListEntry = Page->ListEntry.Flink;
    if (NextListEntry == &UserPageListHead)
    {
       KeReleaseSpinLock(&PageListLock, oldIrql);
@@ -111,6 +106,13 @@ MmGetLRUNextUserPage(PFN_TYPE PreviousPfn)
    return PageDescriptor - MmPageArray;
 }
 
+VOID
+NTAPI
+MmRemoveLRUUserPage(PFN_TYPE Page)
+{
+   RemoveEntryList(&MiGetPfnEntry(Page)->ListEntry);
+}
+
 PFN_TYPE
 NTAPI
 MmGetContinuousPages(ULONG NumberOfBytes,
@@ -782,7 +784,6 @@ MmAllocPage(ULONG Consumer, SWAPENTRY SavedSwapEntry)
    KeReleaseSpinLock(&PageListLock, oldIrql);
 
    PfnOffset = PageDescriptor - MmPageArray;
-   MmSetLRULastPage(PfnOffset);
    if (NeedClear)
    {
       MiZeroPage(PfnOffset);
@@ -882,7 +883,7 @@ MmAllocPagesSpecifyRange(ULONG Consumer,
          /* Remember the page */
          pfn = PageDescriptor - MmPageArray;
          Pages[NumberOfPagesFound++] = pfn;
-         MmSetLRULastPage(pfn);
+         if(Consumer == MC_USER) MmInsertLRULastUserPage(pfn);
       }
    }
    else
@@ -917,7 +918,6 @@ MmAllocPagesSpecifyRange(ULONG Consumer,
 
             /* Remember the page */
             Pages[NumberOfPagesFound++] = pfn;
-            MmSetLRULastPage(pfn);
             if (NumberOfPagesFound == NumberOfPages)
                break;
          }
diff --git a/reactos/ntoskrnl/mm/wset.c b/reactos/ntoskrnl/mm/wset.c
index 45d78b99314..df570353d6c 100644
--- a/reactos/ntoskrnl/mm/wset.c
+++ b/reactos/ntoskrnl/mm/wset.c
@@ -38,7 +38,8 @@ MmTrimUserMemory(ULONG Target, ULONG Priority, PULONG NrFreedPages)
       }
       else if (Status == STATUS_PAGEFILE_QUOTA)
       {
-         MmSetLRULastPage(CurrentPage);
+         MmRemoveLRUUserPage(CurrentPage);
+         MmInsertLRULastUserPage(CurrentPage);
       }
 
       CurrentPage = NextPage;