reactos/ntoskrnl/mm/mpw.c

   1 /*
   2  *  ReactOS kernel
   3  *  Copyright (C) 1998, 1999, 2000, 2001 ReactOS Team
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19 /* $Id$
  20  *
  21  * PROJECT:      ReactOS kernel
  22  * FILE:         ntoskrnl/mm/mpw.c
  23  * PURPOSE:      Writes data that has been modified in memory but not on
  24  *               the disk
  25  * PROGRAMMER:   David Welch (welch@cwcom.net)
  26  * UPDATE HISTORY:
  27  *               27/05/98: Created
  28  */
  29
  30 /* INCLUDES ****************************************************************/
  31
  32 #include <ntoskrnl.h>
  33 #define NDEBUG
  34 #include <internal/debug.h>
  35
  36 /* GLOBALS *******************************************************************/
  37
  38 static HANDLE MpwThreadHandle;
  39 static CLIENT_ID MpwThreadId;
  40 static KEVENT MpwThreadEvent;
  41 static volatile BOOLEAN MpwThreadShouldTerminate;
  42
  43 /* FUNCTIONS *****************************************************************/
  44
  45 NTSTATUS STDCALL
  46 MmWriteDirtyPages(ULONG Target, PULONG Actual)
  47 {
  48    PFN_TYPE Page;
  49    PFN_TYPE NextPage;
  50    NTSTATUS Status;
  51
  52    Page = MmGetLRUFirstUserPage();
  53    while (Page != 0 && Target > 0)
  54    {
  55       /*
  56        * FIXME: While the current page is write back it is possible
  57        *        that the next page is freed and not longer a user page.
  58        */
  59       NextPage = MmGetLRUNextUserPage(Page);
  60       if (MmIsDirtyPageRmap(Page))
  61       {
  62          Status = MmWritePagePhysicalAddress(Page);
  63          if (NT_SUCCESS(Status))
  64          {
  65             Target--;
  66          }
  67       }
  68       Page = NextPage;
  69    }
  70    *Actual = Target;
  71    return(STATUS_SUCCESS);
  72 }
  73
  74 NTSTATUS STDCALL
  75 MmMpwThreadMain(PVOID Ignored)
  76 {
  77    NTSTATUS Status;
  78    ULONG PagesWritten;
  79    LARGE_INTEGER Timeout;
  80
  81    Timeout.QuadPart = -50000000;
  82
  83    for(;;)
  84    {
  85       Status = KeWaitForSingleObject(&MpwThreadEvent,
  86                                      0,
  87                                      KernelMode,
  88                                      FALSE,
  89                                      &Timeout);
  90       if (!NT_SUCCESS(Status))
  91       {
  92          DbgPrint("MpwThread: Wait failed\n");
  93          KEBUGCHECK(0);
  94          return(STATUS_UNSUCCESSFUL);
  95       }
  96       if (MpwThreadShouldTerminate)
  97       {
  98          DbgPrint("MpwThread: Terminating\n");
  99          return(STATUS_SUCCESS);
 100       }
 101
 102       PagesWritten = 0;
 103 #if 0
 104       /*
 105        *  FIXME: MmWriteDirtyPages doesn't work correctly.
 106        */
 107       MmWriteDirtyPages(128, &PagesWritten);
 108 #endif
 109
 110       CcRosFlushDirtyPages(128, &PagesWritten);
 111    }
 112 }
 113
 114 NTSTATUS MmInitMpwThread(VOID)
 115 {
 116    KPRIORITY Priority;
 117    NTSTATUS Status;
 118
 119    MpwThreadShouldTerminate = FALSE;
 120    KeInitializeEvent(&MpwThreadEvent, SynchronizationEvent, FALSE);
 121
 122    Status = PsCreateSystemThread(&MpwThreadHandle,
 123                                  THREAD_ALL_ACCESS,
 124                                  NULL,
 125                                  NULL,
 126                                  &MpwThreadId,
 127                                  (PKSTART_ROUTINE) MmMpwThreadMain,
 128                                  NULL);
 129    if (!NT_SUCCESS(Status))
 130    {
 131       return(Status);
 132    }
 133
 134    Priority = 1;
 135    NtSetInformationThread(MpwThreadHandle,
 136                           ThreadPriority,
 137                           &Priority,
 138                           sizeof(Priority));
 139
 140    return(STATUS_SUCCESS);
 141 }