PFN_COUNT
MiRemovePhysicalPages (
IN PFN_NUMBER StartPage,
IN PFN_NUMBER EndPage
)
/*++
Routine Description:
This routine searches the PFN database for free, zeroed or standby pages
that are marked for removal.
Arguments:
StartPage - Supplies the low physical frame number to remove.
EndPage - Supplies the last physical frame number to remove.
Return Value:
Returns the number of pages removed from the free, zeroed and standby lists.
Environment:
Kernel mode, PFN lock held.
--*/
{
PMMPFN Pfn1;
PMMPFN Pfn2;
PMMPFN PfnNextColored;
PMMPFN PfnNextFlink;
PMMPFN PfnLastColored;
PFN_NUMBER Page;
LOGICAL RemovePage;
ULONG Color;
PMMCOLOR_TABLES ColorHead;
PFN_NUMBER MovedPage;
MMLISTS MemoryList;
PFN_NUMBER PageNextColored;
PFN_NUMBER PageNextFlink;
PFN_NUMBER PageLastColored;
PFN_COUNT NumberOfPages;
PMMPFNLIST ListHead;
LOGICAL RescanNeeded;
MM_PFN_LOCK_ASSERT();
NumberOfPages = 0;
rescan:
//
// Grab all zeroed (and then free) pages first directly from the
// colored lists to avoid multiple walks down these singly linked lists.
// Handle transition pages last.
//
for (MemoryList = ZeroedPageList; MemoryList <= FreePageList; MemoryList += 1) {
ListHead = MmPageLocationList[MemoryList];
for (Color = 0; Color < MmSecondaryColors; Color += 1) {
ColorHead = &MmFreePagesByColor[MemoryList][Color];
MovedPage = MM_EMPTY_LIST;
while (ColorHead->Flink != MM_EMPTY_LIST) {
Page = ColorHead->Flink;
Pfn1 = MI_PFN_ELEMENT(Page);
ASSERT ((MMLISTS)Pfn1->u3.e1.PageLocation == MemoryList);
//
// The Flink and Blink must be nonzero here for the page
// to be on the listhead. Only code that scans the
// MmPhysicalMemoryBlock has to check for the zero case.
//
ASSERT (Pfn1->u1.Flink != 0);
ASSERT (Pfn1->u2.Blink != 0);
//
// See if the page is desired by the caller.
//
if (Pfn1->u3.e1.RemovalRequested == 1) {
ASSERT (Pfn1->u3.e1.ReadInProgress == 0);
MiUnlinkFreeOrZeroedPage (Page);
MiInsertPageInList (MmPageLocationList[BadPageList],
Page);
NumberOfPages += 1;
}
else {
//
// Unwanted so put the page on the end of list.
// If first time, save pfn.
//
if (MovedPage == MM_EMPTY_LIST) {
MovedPage = Page;
}
else if (Page == MovedPage) {
//
// No more pages available in this colored chain.
//
break;
}
//
// If the colored chain has more than one entry then
// put this page on the end.
//
PageNextColored = (PFN_NUMBER)Pfn1->OriginalPte.u.Long;
if (PageNextColored == MM_EMPTY_LIST) {
//
// No more pages available in this colored chain.
//
break;
}
ASSERT (Pfn1->u1.Flink != 0);
ASSERT (Pfn1->u1.Flink != MM_EMPTY_LIST);
ASSERT (Pfn1->PteFrame != MI_MAGIC_AWE_PTEFRAME);
PfnNextColored = MI_PFN_ELEMENT(PageNextColored);
ASSERT ((MMLISTS)PfnNextColored->u3.e1.PageLocation == MemoryList);
ASSERT (PfnNextColored->PteFrame != MI_MAGIC_AWE_PTEFRAME);
//
// Adjust the free page list so Page
// follows PageNextFlink.
//
PageNextFlink = Pfn1->u1.Flink;
PfnNextFlink = MI_PFN_ELEMENT(PageNextFlink);
ASSERT ((MMLISTS)PfnNextFlink->u3.e1.PageLocation == MemoryList);
ASSERT (PfnNextFlink->PteFrame != MI_MAGIC_AWE_PTEFRAME);
PfnLastColored = ColorHead->Blink;
ASSERT (PfnLastColored != (PMMPFN)MM_EMPTY_LIST);
ASSERT (PfnLastColored->OriginalPte.u.Long == MM_EMPTY_LIST);
ASSERT (PfnLastColored->PteFrame != MI_MAGIC_AWE_PTEFRAME);
ASSERT (PfnLastColored->u2.Blink != MM_EMPTY_LIST);
ASSERT ((MMLISTS)PfnLastColored->u3.e1.PageLocation == MemoryList);
PageLastColored = PfnLastColored - MmPfnDatabase;
if (ListHead->Flink == Page) {
ASSERT (Pfn1->u2.Blink == MM_EMPTY_LIST);
ASSERT (ListHead->Blink != Page);
ListHead->Flink = PageNextFlink;
PfnNextFlink->u2.Blink = MM_EMPTY_LIST;
}
else {
ASSERT (Pfn1->u2.Blink != MM_EMPTY_LIST);
ASSERT ((MMLISTS)(MI_PFN_ELEMENT((MI_PFN_ELEMENT(Pfn1->u2.Blink)->u1.Flink)))->PteFrame != MI_MAGIC_AWE_PTEFRAME);
ASSERT ((MMLISTS)(MI_PFN_ELEMENT((MI_PFN_ELEMENT(Pfn1->u2.Blink)->u1.Flink)))->u3.e1.PageLocation == MemoryList);
MI_PFN_ELEMENT(Pfn1->u2.Blink)->u1.Flink = PageNextFlink;
PfnNextFlink->u2.Blink = Pfn1->u2.Blink;
}
#if DBG
if (PfnLastColored->u1.Flink == MM_EMPTY_LIST) {
ASSERT (ListHead->Blink == PageLastColored);
}
#endif
Pfn1->u1.Flink = PfnLastColored->u1.Flink;
Pfn1->u2.Blink = PageLastColored;
if (ListHead->Blink == PageLastColored) {
ListHead->Blink = Page;
}
//
// Adjust the colored chains.
//
if (PfnLastColored->u1.Flink != MM_EMPTY_LIST) {
ASSERT (MI_PFN_ELEMENT(PfnLastColored->u1.Flink)->PteFrame != MI_MAGIC_AWE_PTEFRAME);
ASSERT ((MMLISTS)(MI_PFN_ELEMENT(PfnLastColored->u1.Flink)->u3.e1.PageLocation) == MemoryList);
MI_PFN_ELEMENT(PfnLastColored->u1.Flink)->u2.Blink = Page;
}
PfnLastColored->u1.Flink = Page;
ColorHead->Flink = PageNextColored;
Pfn1->OriginalPte.u.Long = MM_EMPTY_LIST;
ASSERT (PfnLastColored->OriginalPte.u.Long == MM_EMPTY_LIST);
PfnLastColored->OriginalPte.u.Long = Page;
ColorHead->Blink = Pfn1;
}
}
}
}
RescanNeeded = FALSE;
Pfn1 = MI_PFN_ELEMENT (StartPage);
do {
if ((Pfn1->u3.e1.PageLocation == StandbyPageList) &&
(Pfn1->u1.Flink != 0) &&
(Pfn1->u2.Blink != 0) &&
(Pfn1->u3.e2.ReferenceCount == 0)) {
ASSERT (Pfn1->u3.e1.ReadInProgress == 0);
RemovePage = TRUE;
if (Pfn1->u3.e1.RemovalRequested == 0) {
//
// This page is not directly needed for a hot remove - but if
// it contains a chunk of prototype PTEs (and this chunk is
// in a page that needs to be removed), then any pages
// referenced by transition prototype PTEs must also be removed
// before the desired page can be removed.
//
// The same analogy holds for page parent, directory and table
// pages.
//
Pfn2 = MI_PFN_ELEMENT (Pfn1->PteFrame);
if (Pfn2->u3.e1.RemovalRequested == 0) {
#if defined (_WIN64)
Pfn2 = MI_PFN_ELEMENT (Pfn2->PteFrame);
if (Pfn2->u3.e1.RemovalRequested == 0) {
RemovePage = FALSE;
}
else if (Pfn2->u2.ShareCount == 1) {
RescanNeeded = TRUE;
}
#else
RemovePage = FALSE;
#endif
}
else if (Pfn2->u2.ShareCount == 1) {
RescanNeeded = TRUE;
}
}
if (RemovePage == TRUE) {
//
// This page is in the desired range - grab it.
//
MiUnlinkPageFromList (Pfn1);
MiRestoreTransitionPte (StartPage);
MiInsertPageInList (MmPageLocationList[BadPageList],
StartPage);
NumberOfPages += 1;
}
}
StartPage += 1;
Pfn1 += 1;
} while (StartPage < EndPage);
if (RescanNeeded == TRUE) {
//
// A page table, directory or parent was freed by removing a transition
// page from the cache. Rescan from the top to pick it up.
//
#if DBG
MiDynmemData[7] += 1;
#endif
goto rescan;
}
#if DBG
else {
MiDynmemData[8] += 1;
}
#endif
return NumberOfPages;
}
VOID
FASTCALL
MiDecrementReferenceCount (
IN PMMPFN Pfn1,
IN PFN_NUMBER PageFrameIndex
)
/*++
Routine Description:
This routine decrements the reference count for the specified page.
If the reference count becomes zero, the page is placed on the
appropriate list (free, modified, standby or bad). If the page
is placed on the free or standby list, the number of available
pages is incremented and if it transitions from zero to one, the
available page event is set.
Arguments:
Pfn1 - Supplies the PFN database entry to decrement.
PageFrameIndex - Supplies the physical page number of which to
decrement the reference count.
Return Value:
None.
Environment:
Must be holding the PFN database lock with APCs disabled.
--*/
{
ULONG FreeBit;
MM_PFN_LOCK_ASSERT();
ASSERT (MI_IS_PFN (PageFrameIndex));
ASSERT (Pfn1 == MI_PFN_ELEMENT (PageFrameIndex));
ASSERT (Pfn1->u3.e2.ReferenceCount != 0);
InterlockedDecrementPfn ((PSHORT)&Pfn1->u3.e2.ReferenceCount);
if (Pfn1->u3.e2.ReferenceCount != 0) {
//
// The reference count is not zero, return.
//
return;
}
//
// The reference count is now zero, put the page on some list.
//
if (Pfn1->u2.ShareCount != 0) {
KeBugCheckEx (PFN_LIST_CORRUPT,
7,
PageFrameIndex,
Pfn1->u2.ShareCount,
0);
return;
}
ASSERT (Pfn1->u3.e1.PageLocation != ActiveAndValid);
if (MI_IS_PFN_DELETED (Pfn1)) {
//
// There is no referenced PTE for this page, delete the page
// file space (if any), and place the page on the free list.
//
if (Pfn1->OriginalPte.u.Soft.Prototype == 0) {
FreeBit = GET_PAGING_FILE_OFFSET (Pfn1->OriginalPte);
if ((FreeBit != 0) && (FreeBit != MI_PTE_LOOKUP_NEEDED)) {
MiReleaseConfirmedPageFileSpace (Pfn1->OriginalPte);
}
}
MiInsertPageInFreeList (PageFrameIndex);
return;
}
//
// Place the page on the modified or standby list depending
// on the state of the modify bit in the PFN element.
//
if (Pfn1->u3.e1.Modified == 1) {
MiInsertPageInList (&MmModifiedPageListHead, PageFrameIndex);
}
else {
if (Pfn1->u3.e1.RemovalRequested == 1) {
//
// The page may still be marked as on the modified list if the
// current thread is the modified writer completing the write.
// Mark it as standby so restoration of the transition PTE
// doesn't flag this as illegal.
//
Pfn1->u3.e1.PageLocation = StandbyPageList;
MiRestoreTransitionPte (Pfn1);
MiInsertPageInList (&MmBadPageListHead, PageFrameIndex);
return;
}
if (!MmFrontOfList) {
MiInsertPageInList (&MmStandbyPageListHead, PageFrameIndex);
}
else {
MiInsertStandbyListAtFront (PageFrameIndex);
}
}
return;
}
