reactos/ntoskrnl/mm/mpw.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/mm/mpw.c
   6  * PURPOSE:         Writes data that has been modified in memory but not on
   7  *                  the disk
   8  *
   9  * PROGRAMMERS:     David Welch (welch@cwcom.net)
  10  */
  11
  12 /* INCLUDES ****************************************************************/
  13
  14 #include <ntoskrnl.h>
  15 #define NDEBUG
  16 #include <internal/debug.h>
  17
  18 /* GLOBALS *******************************************************************/
  19
  20 static HANDLE MpwThreadHandle;
  21 static CLIENT_ID MpwThreadId;
  22 static KEVENT MpwThreadEvent;
  23 static volatile BOOLEAN MpwThreadShouldTerminate;
  24
  25 /* FUNCTIONS *****************************************************************/
  26
  27 NTSTATUS STDCALL
  28 MmWriteDirtyPages(ULONG Target, PULONG Actual)
  29 {
  30    PFN_TYPE Page;
  31    PFN_TYPE NextPage;
  32    NTSTATUS Status;
  33
  34    Page = MmGetLRUFirstUserPage();
  35    while (Page != 0 && Target > 0)
  36    {
  37       /*
  38        * FIXME: While the current page is write back it is possible
  39        *        that the next page is freed and not longer a user page.
  40        */
  41       NextPage = MmGetLRUNextUserPage(Page);
  42       if (MmIsDirtyPageRmap(Page))
  43       {
  44          Status = MmWritePagePhysicalAddress(Page);
  45          if (NT_SUCCESS(Status))
  46          {
  47             Target--;
  48          }
  49       }
  50       Page = NextPage;
  51    }
  52    *Actual = Target;
  53    return(STATUS_SUCCESS);
  54 }
  55
  56 NTSTATUS STDCALL
  57 MmMpwThreadMain(PVOID Ignored)
  58 {
  59    NTSTATUS Status;
  60    ULONG PagesWritten;
  61    LARGE_INTEGER Timeout;
  62
  63    Timeout.QuadPart = -50000000;
  64
  65    for(;;)
  66    {
  67       Status = KeWaitForSingleObject(&MpwThreadEvent,
  68                                      0,
  69                                      KernelMode,
  70                                      FALSE,
  71                                      &Timeout);
  72       if (!NT_SUCCESS(Status))
  73       {
  74          DbgPrint("MpwThread: Wait failed\n");
  75          KEBUGCHECK(0);
  76          return(STATUS_UNSUCCESSFUL);
  77       }
  78       if (MpwThreadShouldTerminate)
  79       {
  80          DbgPrint("MpwThread: Terminating\n");
  81          return(STATUS_SUCCESS);
  82       }
  83
  84       PagesWritten = 0;
  85 #if 0
  86       /*
  87        *  FIXME: MmWriteDirtyPages doesn't work correctly.
  88        */
  89       MmWriteDirtyPages(128, &PagesWritten);
  90 #endif
  91
  92       CcRosFlushDirtyPages(128, &PagesWritten);
  93    }
  94 }
  95
  96 NTSTATUS
  97 NTAPI
  98 MmInitMpwThread(VOID)
  99 {
 100    KPRIORITY Priority;
 101    NTSTATUS Status;
 102
 103    MpwThreadShouldTerminate = FALSE;
 104    KeInitializeEvent(&MpwThreadEvent, SynchronizationEvent, FALSE);
 105
 106    Status = PsCreateSystemThread(&MpwThreadHandle,
 107                                  THREAD_ALL_ACCESS,
 108                                  NULL,
 109                                  NULL,
 110                                  &MpwThreadId,
 111                                  (PKSTART_ROUTINE) MmMpwThreadMain,
 112                                  NULL);
 113    if (!NT_SUCCESS(Status))
 114    {
 115       return(Status);
 116    }
 117
 118    Priority = 1;
 119    NtSetInformationThread(MpwThreadHandle,
 120                           ThreadPriority,
 121                           &Priority,
 122                           sizeof(Priority));
 123
 124    return(STATUS_SUCCESS);
 125 }
 126
 127 NTSTATUS
 128 NTAPI
 129 MmInitBsmThread(VOID)
 130 {
 131     NTSTATUS Status;
 132     OBJECT_ATTRIBUTES ObjectAttributes;
 133     HANDLE ThreadHandle;
 134
 135     /* Create the thread */
 136     InitializeObjectAttributes(&ObjectAttributes, NULL, 0, NULL, NULL);
 137     Status = PsCreateSystemThread(&ThreadHandle,
 138                                   THREAD_ALL_ACCESS,
 139                                   &ObjectAttributes,
 140                                   NULL,
 141                                   NULL,
 142                                   KeBalanceSetManager,
 143                                   NULL);
 144
 145     /* Close the handle and return status */
 146     ZwClose(ThreadHandle);
 147     return Status;
 148 }