833 lines
18 KiB
C
833 lines
18 KiB
C
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/*++
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Copyright (c) 1995 Microsoft Corporation
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Module Name:
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lookasid.c
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Abstract:
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This module implements lookaside list function.
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Author:
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David N. Cutler (davec) 19-Feb-1995
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Revision History:
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--*/
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#include "exp.h"
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// Define maximum dynamic adjustment scan periods.
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#define MAXIMUM_SCAN_PERIOD 4
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// Define Minimum lookaside list depth.
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#define MINIMUM_LOOKASIDE_DEPTH 4
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// Define minimum allocation threshold.
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#define MINIMUM_ALLOCATION_THRESHOLD 25
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// Define forward referenced function prototypes.
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LOGICAL
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ExpComputeLookasideDepth (
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IN ULONG Allocates,
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IN ULONG Misses,
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IN USHORT MaximumDepth,
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IN OUT PUSHORT Depth
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);
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PVOID
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ExpDummyAllocate (
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IN POOL_TYPE PoolType,
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IN SIZE_T NumberOfBytes,
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IN ULONG Tag
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);
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LOGICAL
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ExpScanGeneralLookasideList (
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IN PLIST_ENTRY ListHead,
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IN PKSPIN_LOCK SpinLock
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);
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LOGICAL
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ExpScanPoolLookasideList (
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IN PLIST_ENTRY ListHead
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);
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// Define the global nonpaged and paged lookaside list data.
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LIST_ENTRY ExNPagedLookasideListHead;
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KSPIN_LOCK ExNPagedLookasideLock;
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LIST_ENTRY ExPagedLookasideListHead;
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KSPIN_LOCK ExPagedLookasideLock;
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LIST_ENTRY ExPoolLookasideListHead;
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// Define lookaside list dynamic adjustment data.
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ULONG ExpAdjustScanPeriod = 1;
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ULONG ExpCurrentScanPeriod = 1;
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VOID
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ExAdjustLookasideDepth (
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VOID
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)
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/*++
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Routine Description:
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This function is called periodically to adjust the maximum depth of
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all lookaside lists.
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Arguments:
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None.
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Return Value:
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None.
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--*/
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{
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LOGICAL Changes;
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// Decrement the scan period and check if it is time to dynamically
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// adjust the maximum depth of lookaside lists.
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ExpCurrentScanPeriod -= 1;
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if (ExpCurrentScanPeriod == 0) {
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Changes = FALSE;
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// Scan the general paged and nonpaged lookaside lists.
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Changes |= ExpScanGeneralLookasideList(&ExNPagedLookasideListHead,
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&ExNPagedLookasideLock);
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Changes |= ExpScanGeneralLookasideList(&ExPagedLookasideListHead,
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&ExPagedLookasideLock);
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// Scan the pool paged and nonpaged lookaside lists;
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Changes |= ExpScanPoolLookasideList(&ExPoolLookasideListHead);
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// If any changes were made to the depth of any lookaside list during
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// this scan period, then lower the scan period to the minimum value.
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// Otherwise, attempt to raise the scan period.
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if (Changes != FALSE) {
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ExpAdjustScanPeriod = 1;
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} else {
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if (ExpAdjustScanPeriod != MAXIMUM_SCAN_PERIOD) {
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ExpAdjustScanPeriod += 1;
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}
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}
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ExpCurrentScanPeriod = ExpAdjustScanPeriod;
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}
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return;
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}
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LOGICAL
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ExpComputeLookasideDepth (
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IN ULONG Allocates,
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IN ULONG Misses,
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IN USHORT MaximumDepth,
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IN OUT PUSHORT Depth
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)
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/*++
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Routine Description:
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This function computes the target depth of a lookaside list given the
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total allocations and misses during the last scan period and the current
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depth.
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Arguments:
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Allocates - Supplies the total number of allocations during the last
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scan period.
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Misses - Supplies the total number of allocate misses during the last
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scan period.
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MaximumDepth - Supplies the maximum depth the lookaside list is allowed
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to reach.
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Depth - Supplies a pointer to the current lookaside list depth which
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receives the target depth.
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Return Value:
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If the target depth is greater than the current depth, then a value of
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TRUE is returned as the function value. Otherwise, a value of FALSE is
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returned.
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--*/
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{
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LOGICAL Changes;
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ULONG Ratio;
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ULONG Target;
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// If the allocate rate is less than the mimimum threshold, then lower
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// the maximum depth of the lookaside list. Otherwise, if the miss rate
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// is less than .5%, then lower the maximum depth. Otherwise, raise the
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// maximum depth based on the miss rate.
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Changes = FALSE;
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if (Misses >= Allocates) {
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Misses = Allocates;
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}
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if (Allocates == 0) {
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Allocates = 1;
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}
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Ratio = (Misses * 1000) / Allocates;
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Target = *Depth;
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if ((Allocates / ExpAdjustScanPeriod) < MINIMUM_ALLOCATION_THRESHOLD) {
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if (Target > (MINIMUM_LOOKASIDE_DEPTH + 10)) {
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Target -= 10;
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} else {
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Target = MINIMUM_LOOKASIDE_DEPTH;
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}
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} else if (Ratio < 5) {
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if (Target > (MINIMUM_LOOKASIDE_DEPTH + 1)) {
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Target -= 1;
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} else {
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Target = MINIMUM_LOOKASIDE_DEPTH;
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}
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} else {
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Changes = TRUE;
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Target += ((Ratio * MaximumDepth) / (1000 * 2)) + 5;
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if (Target > MaximumDepth) {
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Target = MaximumDepth;
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}
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}
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*Depth = (USHORT)Target;
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return Changes;
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}
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LOGICAL
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ExpScanGeneralLookasideList (
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IN PLIST_ENTRY ListHead,
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IN PKSPIN_LOCK SpinLock
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)
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/*++
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Routine Description:
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This function scans the specified list of general lookaside descriptors
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and adjusts the maximum depth as necessary.
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Arguments:
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ListHead - Supplies the address of the listhead for a list of lookaside
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descriptors.
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SpinLock - Supplies the address of the spinlock to be used to synchronize
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access to the list of lookaside descriptors.
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Return Value:
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A value of TRUE is returned if the maximum depth of any lookaside list
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is changed. Otherwise, a value of FALSE is returned.
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--*/
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{
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ULONG Allocates;
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LOGICAL Changes;
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PLIST_ENTRY Entry;
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PPAGED_LOOKASIDE_LIST Lookaside;
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ULONG Misses;
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KIRQL OldIrql;
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// Raise IRQL and acquire the specified spinlock.
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Changes = FALSE;
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ExAcquireSpinLock(SpinLock, &OldIrql);
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// Scan the specified list of lookaside descriptors and adjust the
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// maximum depth as necessary.
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// N.B. All lookaside list descriptor are treated as if they were
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// paged descriptor even though they may be nonpaged descriptors.
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// This is possible since both structures are identical except
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// for the locking fields which are the last structure fields.
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Entry = ListHead->Flink;
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while (Entry != ListHead) {
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Lookaside = CONTAINING_RECORD(Entry,
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PAGED_LOOKASIDE_LIST,
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L.ListEntry);
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// Compute the total number of allocations and misses per second for
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// this scan period.
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Allocates = Lookaside->L.TotalAllocates - Lookaside->L.LastTotalAllocates;
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Lookaside->L.LastTotalAllocates = Lookaside->L.TotalAllocates;
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Misses = Lookaside->L.AllocateMisses - Lookaside->L.LastAllocateMisses;
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Lookaside->L.LastAllocateMisses = Lookaside->L.AllocateMisses;
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// Compute target depth of lookaside list.
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Changes |= ExpComputeLookasideDepth(Allocates,
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Misses,
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Lookaside->L.MaximumDepth,
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&Lookaside->L.Depth);
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Entry = Entry->Flink;
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}
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// Release spinlock, lower IRQL, and return function value.
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ExReleaseSpinLock(SpinLock, OldIrql);
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return Changes;
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}
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LOGICAL
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ExpScanPoolLookasideList (
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IN PLIST_ENTRY ListHead
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)
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/*++
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Routine Description:
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This function scans the specified pool lookaside descriptors and adjusts
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the maximum depth as necessary.
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Arguments:
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ListHead - Supplies a pointer to the list of pool lookaside structures.
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Return Value:
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A value of TRUE is returned if the maximum depth of any lookaside list
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is changed. Otherwise, a value of FALSE is returned.
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--*/
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{
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ULONG Allocates;
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LOGICAL Changes;
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PNPAGED_LOOKASIDE_LIST Lookaside;
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PLIST_ENTRY NextEntry;
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ULONG Misses;
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// Scan the specified list of lookaside descriptors and adjust the
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// maximum depth as necessary.
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Changes = FALSE;
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NextEntry = ListHead->Flink;
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while (NextEntry != ListHead) {
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Lookaside = CONTAINING_RECORD(NextEntry,
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NPAGED_LOOKASIDE_LIST,
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L.ListEntry);
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// Compute the total number of allocations and misses per second for
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// this scan period.
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Allocates = Lookaside->L.TotalAllocates - Lookaside->L.LastTotalAllocates;
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Lookaside->L.LastTotalAllocates = Lookaside->L.TotalAllocates;
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Misses = Allocates - (Lookaside->L.AllocateHits - Lookaside->L.LastAllocateHits);
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Lookaside->L.LastAllocateHits = Lookaside->L.AllocateHits;
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// Compute target depth of lookaside list.
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Changes |= ExpComputeLookasideDepth(Allocates,
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Misses,
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Lookaside->L.MaximumDepth,
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&Lookaside->L.Depth);
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NextEntry = NextEntry->Flink;
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}
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return Changes;
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}
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VOID
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ExInitializeNPagedLookasideList (
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IN PNPAGED_LOOKASIDE_LIST Lookaside,
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IN PALLOCATE_FUNCTION Allocate,
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IN PFREE_FUNCTION Free,
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IN ULONG Flags,
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IN SIZE_T Size,
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IN ULONG Tag,
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IN USHORT Depth
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)
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/*++
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Routine Description:
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This function initializes a nonpaged lookaside list structure and inserts
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the structure in the system nonpaged lookaside list.
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Arguments:
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Lookaside - Supplies a pointer to a nonpaged lookaside list structure.
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Allocate - Supplies an optional pointer to an allocate function.
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Free - Supplies an optional pointer to a free function.
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Flags - Supplies the pool allocation flags which are merged with the
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pool allocation type (NonPagedPool) to control pool allocation.
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Size - Supplies the size for the lookaside list entries.
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Tag - Supplies the pool tag for the lookaside list entries.
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Depth - Supplies the maximum depth of the lookaside list.
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Return Value:
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None.
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--*/
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{
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// Initialize the lookaside list structure.
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ExInitializeSListHead(&Lookaside->L.ListHead);
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Lookaside->L.Depth = MINIMUM_LOOKASIDE_DEPTH;
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Lookaside->L.MaximumDepth = 256; //Depth;
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Lookaside->L.TotalAllocates = 0;
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Lookaside->L.AllocateMisses = 0;
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Lookaside->L.TotalFrees = 0;
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Lookaside->L.FreeMisses = 0;
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Lookaside->L.Type = NonPagedPool | Flags;
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Lookaside->L.Tag = Tag;
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Lookaside->L.Size = (ULONG)Size;
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if (Allocate == NULL) {
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Lookaside->L.Allocate = ExAllocatePoolWithTag;
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} else {
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Lookaside->L.Allocate = Allocate;
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}
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if (Free == NULL) {
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Lookaside->L.Free = ExFreePool;
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} else {
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Lookaside->L.Free = Free;
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}
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Lookaside->L.LastTotalAllocates = 0;
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Lookaside->L.LastAllocateMisses = 0;
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KeInitializeSpinLock(&Lookaside->Lock);
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// Insert the lookaside list structure is the system nonpaged lookaside
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// list.
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ExInterlockedInsertTailList(&ExNPagedLookasideListHead,
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&Lookaside->L.ListEntry,
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&ExNPagedLookasideLock);
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return;
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}
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VOID
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ExDeleteNPagedLookasideList (
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IN PNPAGED_LOOKASIDE_LIST Lookaside
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)
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/*++
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Routine Description:
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This function removes a paged lookaside structure from the system paged
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lookaside list and frees any entries specified by the lookaside structure.
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Arguments:
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Lookaside - Supplies a pointer to a nonpaged lookaside list structure.
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Return Value:
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None.
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--*/
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{
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PVOID Entry;
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KIRQL OldIrql;
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// Acquire the nonpaged system lookaside list lock and remove the
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// specified lookaside list structure from the list.
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ExAcquireSpinLock(&ExNPagedLookasideLock, &OldIrql);
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RemoveEntryList(&Lookaside->L.ListEntry);
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ExReleaseSpinLock(&ExNPagedLookasideLock, OldIrql);
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// Remove all pool entries from the specified lookaside structure
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// and free them.
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Lookaside->L.Allocate = ExpDummyAllocate;
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||
|
while ((Entry = ExAllocateFromNPagedLookasideList(Lookaside)) != NULL) {
|
||
|
(Lookaside->L.Free)(Entry);
|
||
|
}
|
||
|
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
VOID
|
||
|
ExInitializePagedLookasideList (
|
||
|
IN PPAGED_LOOKASIDE_LIST Lookaside,
|
||
|
IN PALLOCATE_FUNCTION Allocate,
|
||
|
IN PFREE_FUNCTION Free,
|
||
|
IN ULONG Flags,
|
||
|
IN SIZE_T Size,
|
||
|
IN ULONG Tag,
|
||
|
IN USHORT Depth
|
||
|
)
|
||
|
|
||
|
/*++
|
||
|
|
||
|
Routine Description:
|
||
|
|
||
|
This function initializes a paged lookaside list structure and inserts
|
||
|
the structure in the system paged lookaside list.
|
||
|
|
||
|
Arguments:
|
||
|
|
||
|
Lookaside - Supplies a pointer to a paged lookaside list structure.
|
||
|
|
||
|
Allocate - Supplies an optional pointer to an allocate function.
|
||
|
|
||
|
Free - Supplies an optional pointer to a free function.
|
||
|
|
||
|
Flags - Supplies the pool allocation flags which are merged with the
|
||
|
pool allocation type (NonPagedPool) to control pool allocation.
|
||
|
|
||
|
Size - Supplies the size for the lookaside list entries.
|
||
|
|
||
|
Tag - Supplies the pool tag for the lookaside list entries.
|
||
|
|
||
|
Depth - Supplies the maximum depth of the lookaside list.
|
||
|
|
||
|
Return Value:
|
||
|
|
||
|
None.
|
||
|
|
||
|
--*/
|
||
|
|
||
|
{
|
||
|
|
||
|
|
||
|
// Initialize the lookaside list structure.
|
||
|
|
||
|
|
||
|
ExInitializeSListHead(&Lookaside->L.ListHead);
|
||
|
Lookaside->L.Depth = MINIMUM_LOOKASIDE_DEPTH;
|
||
|
Lookaside->L.MaximumDepth = 256; //Depth;
|
||
|
Lookaside->L.TotalAllocates = 0;
|
||
|
Lookaside->L.AllocateMisses = 0;
|
||
|
Lookaside->L.TotalFrees = 0;
|
||
|
Lookaside->L.FreeMisses = 0;
|
||
|
Lookaside->L.Type = PagedPool | Flags;
|
||
|
Lookaside->L.Tag = Tag;
|
||
|
Lookaside->L.Size = (ULONG)Size;
|
||
|
if (Allocate == NULL) {
|
||
|
Lookaside->L.Allocate = ExAllocatePoolWithTag;
|
||
|
|
||
|
} else {
|
||
|
Lookaside->L.Allocate = Allocate;
|
||
|
}
|
||
|
|
||
|
if (Free == NULL) {
|
||
|
Lookaside->L.Free = ExFreePool;
|
||
|
|
||
|
} else {
|
||
|
Lookaside->L.Free = Free;
|
||
|
}
|
||
|
|
||
|
Lookaside->L.LastTotalAllocates = 0;
|
||
|
Lookaside->L.LastAllocateMisses = 0;
|
||
|
ExInitializeFastMutex(&Lookaside->Lock);
|
||
|
|
||
|
|
||
|
// Insert the lookaside list structure in the system paged lookaside
|
||
|
// list.
|
||
|
|
||
|
|
||
|
ExInterlockedInsertTailList(&ExPagedLookasideListHead,
|
||
|
&Lookaside->L.ListEntry,
|
||
|
&ExPagedLookasideLock);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
VOID
|
||
|
ExDeletePagedLookasideList (
|
||
|
IN PPAGED_LOOKASIDE_LIST Lookaside
|
||
|
)
|
||
|
|
||
|
/*++
|
||
|
|
||
|
Routine Description:
|
||
|
|
||
|
This function removes a paged lookaside structure from the system paged
|
||
|
lookaside list and frees any entries specified by the lookaside structure.
|
||
|
|
||
|
Arguments:
|
||
|
|
||
|
Lookaside - Supplies a pointer to a paged lookaside list structure.
|
||
|
|
||
|
Return Value:
|
||
|
|
||
|
None.
|
||
|
|
||
|
--*/
|
||
|
|
||
|
{
|
||
|
|
||
|
PVOID Entry;
|
||
|
KIRQL OldIrql;
|
||
|
|
||
|
|
||
|
// Acquire the paged system lookaside list lock and remove the
|
||
|
// specified lookaside list structure from the list.
|
||
|
|
||
|
|
||
|
ExAcquireSpinLock(&ExPagedLookasideLock, &OldIrql);
|
||
|
RemoveEntryList(&Lookaside->L.ListEntry);
|
||
|
ExReleaseSpinLock(&ExPagedLookasideLock, OldIrql);
|
||
|
|
||
|
|
||
|
// Remove all pool entries from the specified lookaside structure
|
||
|
// and free them.
|
||
|
|
||
|
|
||
|
Lookaside->L.Allocate = ExpDummyAllocate;
|
||
|
while ((Entry = ExAllocateFromPagedLookasideList(Lookaside)) != NULL) {
|
||
|
(Lookaside->L.Free)(Entry);
|
||
|
}
|
||
|
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
#if !defined(_MIPS_) && !defined(_ALPHA_) && !defined(_IA64_)
|
||
|
|
||
|
|
||
|
PVOID
|
||
|
ExAllocateFromPagedLookasideList(
|
||
|
IN PPAGED_LOOKASIDE_LIST Lookaside
|
||
|
)
|
||
|
|
||
|
/*++
|
||
|
|
||
|
Routine Description:
|
||
|
|
||
|
This function removes (pops) the first entry from the specified
|
||
|
paged lookaside list.
|
||
|
|
||
|
Arguments:
|
||
|
|
||
|
Lookaside - Supplies a pointer to a paged lookaside list structure.
|
||
|
|
||
|
Return Value:
|
||
|
|
||
|
If an entry is removed from the specified lookaside list, then the
|
||
|
address of the entry is returned as the function value. Otherwise,
|
||
|
NULL is returned.
|
||
|
|
||
|
--*/
|
||
|
|
||
|
{
|
||
|
|
||
|
PVOID Entry;
|
||
|
|
||
|
Lookaside->L.TotalAllocates += 1;
|
||
|
|
||
|
if (Isx86FeaturePresent(KF_CMPXCHG8B)) {
|
||
|
if ((Entry = ExInterlockedPopEntrySList(&Lookaside->L.ListHead,
|
||
|
NULL)) == NULL) {
|
||
|
|
||
|
Lookaside->L.AllocateMisses += 1;
|
||
|
Entry = (Lookaside->L.Allocate)(Lookaside->L.Type,
|
||
|
Lookaside->L.Size,
|
||
|
Lookaside->L.Tag);
|
||
|
}
|
||
|
|
||
|
return Entry;
|
||
|
}
|
||
|
|
||
|
ExAcquireFastMutex(&Lookaside->Lock);
|
||
|
Entry = PopEntryList(&Lookaside->L.ListHead.Next);
|
||
|
if (Entry == NULL) {
|
||
|
ExReleaseFastMutex(&Lookaside->Lock);
|
||
|
Lookaside->L.AllocateMisses += 1;
|
||
|
Entry = (Lookaside->L.Allocate)(Lookaside->L.Type,
|
||
|
Lookaside->L.Size,
|
||
|
Lookaside->L.Tag);
|
||
|
|
||
|
} else {
|
||
|
Lookaside->L.ListHead.Depth -= 1;
|
||
|
ExReleaseFastMutex(&Lookaside->Lock);
|
||
|
}
|
||
|
|
||
|
return Entry;
|
||
|
}
|
||
|
|
||
|
VOID
|
||
|
ExFreeToPagedLookasideList(
|
||
|
IN PPAGED_LOOKASIDE_LIST Lookaside,
|
||
|
IN PVOID Entry
|
||
|
)
|
||
|
|
||
|
/*++
|
||
|
|
||
|
Routine Description:
|
||
|
|
||
|
This function inserts (pushes) the specified entry into the specified
|
||
|
paged lookaside list.
|
||
|
|
||
|
Arguments:
|
||
|
|
||
|
Lookaside - Supplies a pointer to a paged lookaside list structure.
|
||
|
|
||
|
Entry - Supples a pointer to the entry that is inserted in the
|
||
|
lookaside list.
|
||
|
|
||
|
Return Value:
|
||
|
|
||
|
None.
|
||
|
|
||
|
--*/
|
||
|
|
||
|
{
|
||
|
|
||
|
Lookaside->L.TotalFrees += 1;
|
||
|
|
||
|
if (Isx86FeaturePresent(KF_CMPXCHG8B)) {
|
||
|
if (ExQueryDepthSList(&Lookaside->L.ListHead) >= Lookaside->L.Depth) {
|
||
|
Lookaside->L.FreeMisses += 1;
|
||
|
(Lookaside->L.Free)(Entry);
|
||
|
|
||
|
} else {
|
||
|
ExInterlockedPushEntrySList(&Lookaside->L.ListHead,
|
||
|
(PSINGLE_LIST_ENTRY)Entry,
|
||
|
NULL);
|
||
|
}
|
||
|
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
ExAcquireFastMutex(&Lookaside->Lock);
|
||
|
if (ExQueryDepthSList(&Lookaside->L.ListHead) >= Lookaside->L.Depth) {
|
||
|
ExReleaseFastMutex(&Lookaside->Lock);
|
||
|
Lookaside->L.FreeMisses += 1;
|
||
|
(Lookaside->L.Free)(Entry);
|
||
|
|
||
|
} else {
|
||
|
PushEntryList(&Lookaside->L.ListHead.Next, (PSINGLE_LIST_ENTRY)Entry);
|
||
|
Lookaside->L.ListHead.Depth += 1;
|
||
|
ExReleaseFastMutex(&Lookaside->Lock);
|
||
|
}
|
||
|
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
#endif
|
||
|
|
||
|
PVOID
|
||
|
ExpDummyAllocate (
|
||
|
IN POOL_TYPE PoolType,
|
||
|
IN SIZE_T NumberOfBytes,
|
||
|
IN ULONG Tag
|
||
|
)
|
||
|
|
||
|
/*++
|
||
|
|
||
|
Routine Description:
|
||
|
|
||
|
This function is a dummy allocation routine which is used to empty
|
||
|
a lookaside list.
|
||
|
|
||
|
Arguments:
|
||
|
|
||
|
PoolType - Supplies the type of pool to allocate.
|
||
|
|
||
|
NumberOfBytes - supplies the number of bytes to allocate.
|
||
|
|
||
|
Tag - supplies the pool tag.
|
||
|
|
||
|
Return Value:
|
||
|
|
||
|
NULL is returned as the function value.
|
||
|
|
||
|
--*/
|
||
|
|
||
|
{
|
||
|
|
||
|
return NULL;
|
||
|
}
|