NTSTATUS
NTAPI
MmRequestPageMemoryConsumer(ULONG Consumer, BOOLEAN CanWait,
PPFN_NUMBER AllocatedPage)
{
ULONG OldUsed;
PFN_NUMBER Page;
KIRQL OldIrql;
/*
* Make sure we don't exceed our individual target.
*/
OldUsed = InterlockedIncrementUL(&MiMemoryConsumers[Consumer].PagesUsed);
if (OldUsed >= (MiMemoryConsumers[Consumer].PagesTarget - 1) &&
!MiIsBalancerThread())
{
if (!CanWait)
{
(void)InterlockedDecrementUL(&MiMemoryConsumers[Consumer].PagesUsed);
return(STATUS_NO_MEMORY);
}
MiTrimMemoryConsumer(Consumer);
}
/*
* Allocate always memory for the non paged pool and for the pager thread.
*/
if ((Consumer == MC_SYSTEM) || MiIsBalancerThread())
{
OldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
Page = MmAllocPage(Consumer);
KeReleaseQueuedSpinLock(LockQueuePfnLock, OldIrql);
if (Page == 0)
{
KeBugCheck(NO_PAGES_AVAILABLE);
}
*AllocatedPage = Page;
if (MmAvailablePages <= MiMinimumAvailablePages &&
MiBalancerThreadHandle != NULL)
{
KeSetEvent(&MiBalancerEvent, IO_NO_INCREMENT, FALSE);
}
return(STATUS_SUCCESS);
}
/*
* Make sure we don't exceed global targets.
*/
if (MmAvailablePages <= MiMinimumAvailablePages)
{
MM_ALLOCATION_REQUEST Request;
if (!CanWait)
{
(void)InterlockedDecrementUL(&MiMemoryConsumers[Consumer].PagesUsed);
return(STATUS_NO_MEMORY);
}
/* Insert an allocation request. */
Request.Page = 0;
KeInitializeEvent(&Request.Event, NotificationEvent, FALSE);
(void)InterlockedIncrementUL(&MiPagesRequired);
KeAcquireSpinLock(&AllocationListLock, &OldIrql);
if (MiBalancerThreadHandle != NULL)
{
KeSetEvent(&MiBalancerEvent, IO_NO_INCREMENT, FALSE);
}
InsertTailList(&AllocationListHead, &Request.ListEntry);
KeReleaseSpinLock(&AllocationListLock, OldIrql);
KeWaitForSingleObject(&Request.Event,
0,
KernelMode,
FALSE,
NULL);
Page = Request.Page;
if (Page == 0)
{
KeBugCheck(NO_PAGES_AVAILABLE);
}
/* Update the Consumer and make the page active */
if(Consumer == MC_USER) MmInsertLRULastUserPage(Page);
*AllocatedPage = Page;
(void)InterlockedDecrementUL(&MiPagesRequired);
return(STATUS_SUCCESS);
}
/*
* Actually allocate the page.
*/
OldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
Page = MmAllocPage(Consumer);
KeReleaseQueuedSpinLock(LockQueuePfnLock, OldIrql);
if (Page == 0)
{
KeBugCheck(NO_PAGES_AVAILABLE);
}
if(Consumer == MC_USER) MmInsertLRULastUserPage(Page);
*AllocatedPage = Page;
return(STATUS_SUCCESS);
}
VOID NTAPI
MiBalancerThread(PVOID Unused)
{
PVOID WaitObjects[2];
NTSTATUS Status;
ULONG i;
WaitObjects[0] = &MiBalancerEvent;
WaitObjects[1] = &MiBalancerTimer;
while (1)
{
Status = KeWaitForMultipleObjects(2,
WaitObjects,
WaitAny,
Executive,
KernelMode,
FALSE,
NULL,
NULL);
if (Status == STATUS_WAIT_0 || Status == STATUS_WAIT_1)
{
ULONG InitialTarget = 0;
#if (_MI_PAGING_LEVELS == 2)
if (!MiIsBalancerThread())
{
/* Clean up the unused PDEs */
ULONG_PTR Address;
PEPROCESS Process = PsGetCurrentProcess();
/* Acquire PFN lock */
KIRQL OldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
PMMPDE pointerPde;
for (Address = (ULONG_PTR)MI_LOWEST_VAD_ADDRESS;
Address < (ULONG_PTR)MM_HIGHEST_VAD_ADDRESS;
Address += (PAGE_SIZE * PTE_COUNT))
{
if (MiQueryPageTableReferences((PVOID)Address) == 0)
{
pointerPde = MiAddressToPde(Address);
if (pointerPde->u.Hard.Valid)
MiDeletePte(pointerPde, MiPdeToPte(pointerPde), Process, NULL);
ASSERT(pointerPde->u.Hard.Valid == 0);
}
}
/* Release lock */
KeReleaseQueuedSpinLock(LockQueuePfnLock, OldIrql);
}
#endif
do
{
ULONG OldTarget = InitialTarget;
/* Trim each consumer */
for (i = 0; i < MC_MAXIMUM; i++)
{
InitialTarget = MiTrimMemoryConsumer(i, InitialTarget);
}
/* No pages left to swap! */
if (InitialTarget != 0 &&
InitialTarget == OldTarget)
{
/* Game over */
KeBugCheck(NO_PAGES_AVAILABLE);
}
} while (InitialTarget != 0);
}
else
{
DPRINT1("KeWaitForMultipleObjects failed, status = %x\n", Status);
KeBugCheck(MEMORY_MANAGEMENT);
}
}
}
