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Why divide up the page array into chunks of 128 pages? Why have a nested loop to initialize system memory in chunks of 128 pages? Why zero the array entries in chunks of 128? The page array is now initialized by simply iterating every page on the system, and filling out its entry in the array.

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Moved out the division calculations even one more step out of the loop -- now they're really calculated once, instead of 1000 times (an improvement over the 400000 times they were calculated previously).

svn path=/trunk/; revision=32358
This commit is contained in:
ReactOS Portable Systems Group 2008-02-14 16:59:14 +00:00
parent 0ef4d8dcdd
commit 4f337a6db1
1 changed files with 111 additions and 122 deletions
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117
reactos/ntoskrnl/mm/freelist.c
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@ -292,6 +292,9 @@ MmInitializePageList(ULONG_PTR FirstPhysKernelAddress,
NTSTATUS Status;
PFN_TYPE LastPage, Pfn;
ULONG PdeStart = PsGetCurrentProcess()->Pcb.DirectoryTableBase.LowPart;
ULONG PdePageStart, PdePageEnd;
ULONG VideoPageStart, VideoPageEnd;
ULONG KernelPageStart, KernelPageEnd;
/* Initialize the page lists */
KeInitializeSpinLock(&PageListLock);
@ -341,21 +344,8 @@ MmInitializePageList(ULONG_PTR FirstPhysKernelAddress,
}
}
/* Now loop every PFN database page again */
for (i = 0; i < Reserved; i++)
{
PVOID Address = (char*)MmPageArray + (i * PAGE_SIZE);
ULONG j, start, end;
ULONG PdePageStart, PdePageEnd;
ULONG VideoPageStart, VideoPageEnd;
ULONG KernelPageStart, KernelPageEnd;
/* Clear the page array entry */
memset(Address, 0, PAGE_SIZE);
/* Do the next page'ss worth of entries */
start = ((ULONG_PTR)Address - (ULONG_PTR)MmPageArray) / sizeof(PHYSICAL_PAGE);
end = ((ULONG_PTR)Address - (ULONG_PTR)MmPageArray + PAGE_SIZE) / sizeof(PHYSICAL_PAGE);
/* Clear the PFN database */
RtlZeroMemory(MmPageArray, MmPageArraySize * sizeof(PHYSICAL_PAGE));
/* We'll be applying a bunch of hacks -- precompute some static values */
PdePageStart = PdeStart / PAGE_SIZE;
@ -365,50 +355,50 @@ MmInitializePageList(ULONG_PTR FirstPhysKernelAddress,
KernelPageStart = FirstPhysKernelAddress / PAGE_SIZE;
KernelPageEnd = LastPhysKernelAddress / PAGE_SIZE;
/* Loop each page in this chunk */
for (j = start; j < end; j++)
/* Loop every page on the system */
for (i = 0; i < MmPageArraySize; i++)
{
/* Check if it's part of RAM */
if (MiIsPfnRam(BIOSMemoryMap, AddressRangeCount, j))
if (MiIsPfnRam(BIOSMemoryMap, AddressRangeCount, i))
{
/* Apply assumptions that all computers are built the same way */
if (j == 0)
if (i == 0)
{
/* Page 0 is reserved for the IVT */
MmPageArray[0].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
MmPageArray[0].Flags.Consumer = MC_NPPOOL;
MmPageArray[0].Flags.Zero = 0;
MmPageArray[0].ReferenceCount = 0;
MmPageArray[i].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
MmPageArray[i].Flags.Consumer = MC_NPPOOL;
MmPageArray[i].Flags.Zero = 0;
MmPageArray[i].ReferenceCount = 0;
MmStats.NrReservedPages++;
}
else if (j == 1)
else if (i == 1)
{
/* Page 1 is reserved for the PCR */
MmPageArray[1].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
MmPageArray[1].Flags.Consumer = MC_NPPOOL;
MmPageArray[1].Flags.Zero = 0;
MmPageArray[1].ReferenceCount = 1;
MmPageArray[i].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
MmPageArray[i].Flags.Consumer = MC_NPPOOL;
MmPageArray[i].Flags.Zero = 0;
MmPageArray[i].ReferenceCount = 1;
MmStats.NrReservedPages++;
}
else if (j == 2)
else if (i == 2)
{
/* Page 2 is reserved for the KUSER_SHARED_DATA */
MmPageArray[2].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
MmPageArray[2].Flags.Consumer = MC_NPPOOL;
MmPageArray[2].Flags.Zero = 0;
MmPageArray[2].ReferenceCount = 1;
MmPageArray[i].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
MmPageArray[i].Flags.Consumer = MC_NPPOOL;
MmPageArray[i].Flags.Zero = 0;
MmPageArray[i].ReferenceCount = 1;
MmStats.NrReservedPages++;
}
else if ((j >= PdePageStart) && (j < PdePageEnd))
else if ((i >= PdePageStart) && (i < PdePageEnd))
{
/* These pages contain the initial FreeLDR PDEs */
MmPageArray[j].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
MmPageArray[j].Flags.Zero = 0;
MmPageArray[j].Flags.Consumer = MC_NPPOOL;
MmPageArray[j].ReferenceCount = 1;
MmPageArray[i].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
MmPageArray[i].Flags.Zero = 0;
MmPageArray[i].Flags.Consumer = MC_NPPOOL;
MmPageArray[i].ReferenceCount = 1;
MmStats.NrReservedPages++;
}
else if ((j >= VideoPageStart) && (j < VideoPageEnd))
else if ((i >= VideoPageStart) && (i < VideoPageEnd))
{
/*
* These pages are usually for the Video ROM BIOS.
@ -416,30 +406,30 @@ MmInitializePageList(ULONG_PTR FirstPhysKernelAddress,
* many systems have this area somewhere else entirely
* (which we'll assume to be "free" a couple of lines below)
*/
MmPageArray[j].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
MmPageArray[j].Flags.Zero = 0;
MmPageArray[j].Flags.Consumer = MC_NPPOOL;
MmPageArray[j].ReferenceCount = 1;
MmPageArray[i].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
MmPageArray[i].Flags.Zero = 0;
MmPageArray[i].Flags.Consumer = MC_NPPOOL;
MmPageArray[i].ReferenceCount = 1;
MmStats.NrReservedPages++;
}
else if ((j >= KernelPageStart) && (j < KernelPageEnd))
else if ((i >= KernelPageStart) && (i < KernelPageEnd))
{
/* These are pages beloning to the kernel */
MmPageArray[j].Flags.Type = MM_PHYSICAL_PAGE_USED;
MmPageArray[j].Flags.Zero = 0;
MmPageArray[j].Flags.Consumer = MC_NPPOOL;
MmPageArray[j].ReferenceCount = 2;
MmPageArray[j].MapCount = 1;
MmPageArray[i].Flags.Type = MM_PHYSICAL_PAGE_USED;
MmPageArray[i].Flags.Zero = 0;
MmPageArray[i].Flags.Consumer = MC_NPPOOL;
MmPageArray[i].ReferenceCount = 2;
MmPageArray[i].MapCount = 1;
MmStats.NrSystemPages++;
}
else if (j > LastPage)
else if (i > LastPage)
{
/* These are pages we allocated above to hold the PFN DB */
MmPageArray[j].Flags.Type = MM_PHYSICAL_PAGE_USED;
MmPageArray[j].Flags.Zero = 0;
MmPageArray[j].Flags.Consumer = MC_NPPOOL;
MmPageArray[j].ReferenceCount = 2;
MmPageArray[j].MapCount = 1;
MmPageArray[i].Flags.Type = MM_PHYSICAL_PAGE_USED;
MmPageArray[i].Flags.Zero = 0;
MmPageArray[i].Flags.Consumer = MC_NPPOOL;
MmPageArray[i].ReferenceCount = 2;
MmPageArray[i].MapCount = 1;
MmStats.NrSystemPages++;
}
else
@ -450,11 +440,11 @@ MmInitializePageList(ULONG_PTR FirstPhysKernelAddress,
* FreeLDR data, but since we choose to ignore the Memory
* Descriptor List, why bother, right?
*/
MmPageArray[j].Flags.Type = MM_PHYSICAL_PAGE_FREE;
MmPageArray[j].Flags.Zero = 0;
MmPageArray[j].ReferenceCount = 0;
MmPageArray[i].Flags.Type = MM_PHYSICAL_PAGE_FREE;
MmPageArray[i].Flags.Zero = 0;
MmPageArray[i].ReferenceCount = 0;
InsertTailList(&FreeUnzeroedPageListHead,
&MmPageArray[j].ListEntry);
&MmPageArray[i].ListEntry);
UnzeroedPageCount++;
MmStats.NrFreePages++;
}
@ -462,14 +452,13 @@ MmInitializePageList(ULONG_PTR FirstPhysKernelAddress,
else
{
/* These are pages reserved by the BIOS/ROMs */
MmPageArray[j].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
MmPageArray[j].Flags.Consumer = MC_NPPOOL;
MmPageArray[j].Flags.Zero = 0;
MmPageArray[j].ReferenceCount = 0;
MmPageArray[i].Flags.Type = MM_PHYSICAL_PAGE_BIOS;
MmPageArray[i].Flags.Consumer = MC_NPPOOL;
MmPageArray[i].Flags.Zero = 0;
MmPageArray[i].ReferenceCount = 0;
MmStats.NrReservedPages++;
}
}
}
KeInitializeEvent(&ZeroPageThreadEvent, NotificationEvent, TRUE);