【精品】PPT课件 Windows Kernel InternalsUser-mode Heap Manager.ppt

文档介绍：Windows Kernel InternalsUser-mode Heap Manager
David B. Probert, .
Windows Kernel Development
Microsoft Corporation
Topics
Common problems with the NT heap
LFH design
Benchmarks data
Heap analysis
Default NT Heap
Unbounded fragmentation for the worst scenario:
External fragmentation
Virtual address fragmentation
Poor performance for:
Large heaps
SMP
Large blocks
Fast growing scenarios
Fragmented heaps
Goals For LFH
Bounded low fragmentation
Low risk (minimal impact)
Stable and high performance for:
Large heaps
Large blocks
SMP
Long running applications
LFH Design
Bucket-oriented heap
Better balance between internal and external fragmentation
Improved data locality
No locking for mon paths
Tradeoffs
Performance / footprint
Internal / external fragmentation
Thread / processor data locality
Using prefetch techniques
LFH
NT Heap
NT Memory Manager
Block Size
0
1K
16 K
512 K
8
16
16 K
NT Heap
128
Buckets
Allocation Granularity
Block Size
Granularity
Buckets
256
8
32
512
16
16
1024
32
16
2048
64
16
4096
128
16
8196
256
16
16384
512
16