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 <ddk/ntddk.h>
  33 #include <internal/ps.h>
  34 #include <internal/mm.h>
  35 #include <internal/cc.h>
  36
  37 #define NDEBUG
  38 #include <internal/debug.h>
  39
  40 /* GLOBALS *******************************************************************/
  41
  42 static HANDLE MpwThreadHandle;
  43 static CLIENT_ID MpwThreadId;
  44 static KEVENT MpwThreadEvent;
  45 static volatile BOOLEAN MpwThreadShouldTerminate;
  46
  47 /* FUNCTIONS *****************************************************************/
  48
  49 NTSTATUS STDCALL
  50 MmWriteDirtyPages(ULONG Target, PULONG Actual)
  51 {
  52   PHYSICAL_ADDRESS Page;
  53   PHYSICAL_ADDRESS NextPage;
  54   NTSTATUS Status;
  55
  56   Page = MmGetLRUFirstUserPage();
  57   while (Page.QuadPart != 0LL && Target > 0)
  58     {
  59       /*
  60        * FIXME: While the current page is write back it is possible
  61        *        that the next page is freed and not longer a user page.
  62        */
  63       NextPage = MmGetLRUNextUserPage(Page);
  64       if (MmIsDirtyPageRmap(Page))
  65         {
  66           Status = MmWritePagePhysicalAddress(Page);
  67           if (NT_SUCCESS(Status))
  68             {
  69               Target--;
  70             }
  71         }
  72       Page = NextPage;
  73     }
  74   *Actual = Target;
  75   return(STATUS_SUCCESS);
  76 }
  77
  78 NTSTATUS STDCALL
  79 MmMpwThreadMain(PVOID Ignored)
  80 {
  81   NTSTATUS Status;
  82   ULONG PagesWritten;
  83   LARGE_INTEGER Timeout;
  84
  85   Timeout.QuadPart = -50000000;
  86
  87   for(;;)
  88     {
  89       Status = KeWaitForSingleObject(&MpwThreadEvent,
  90                                      0,
  91                                      KernelMode,
  92                                      FALSE,
  93                                      &Timeout);
  94       if (!NT_SUCCESS(Status))
  95         {
  96           DbgPrint("MpwThread: Wait failed\n");
  97           KEBUGCHECK(0);
  98           return(STATUS_UNSUCCESSFUL);
  99         }
 100       if (MpwThreadShouldTerminate)
 101         {
 102           DbgPrint("MpwThread: Terminating\n");
 103           return(STATUS_SUCCESS);
 104         }
 105
 106       PagesWritten = 0;
 107 #if 0
 108       /*
 109        *  FIXME: MmWriteDirtyPages doesn't work correctly.
 110        */
 111       MmWriteDirtyPages(128, &PagesWritten);
 112 #endif
 113       CcRosFlushDirtyPages(128, &PagesWritten);
 114     }
 115 }
 116
 117 NTSTATUS MmInitMpwThread(VOID)
 118 {
 119   KPRIORITY Priority;
 120   NTSTATUS Status;
 121
 122   MpwThreadShouldTerminate = FALSE;
 123   KeInitializeEvent(&MpwThreadEvent, SynchronizationEvent, FALSE);
 124
 125   Status = PsCreateSystemThread(&MpwThreadHandle,
 126                                 THREAD_ALL_ACCESS,
 127                                 NULL,
 128                                 NULL,
 129                                 &MpwThreadId,
 130                                 (PKSTART_ROUTINE) MmMpwThreadMain,
 131                                 NULL);
 132   if (!NT_SUCCESS(Status))
 133     {
 134       return(Status);
 135      }
 136
 137   Priority = 1;
 138   NtSetInformationThread(MpwThreadHandle,
 139                          ThreadPriority,
 140                          &Priority,
 141                          sizeof(Priority));
 142
 143   return(STATUS_SUCCESS);
 144 }