The Segregated Binary Trees: Decoupling Memory Manager

Transcription

1 The Segregated Binary Trees: Decoupling Memory Manager Mehran Rezaei Dept. of Electrical and Computer Engineering University of Alabama in Huntsville Ron K. Cytron Department of Computer Science Washington University UAH M. Rezaei

2 Outline Background and Related Work Allocation Policies New Memory Management Techniques Address Ordered Binary Tree (ABT) Segregated Binary Trees (SBT) Memory Management Techniques and Intelligent Memories Empirical Results Storage Utilization Conclusion And Future Work UAH 2 M. Rezaei

3 Existing Memory Management Algorithms (Allocation Policies) Sequential Fit Algorithms First Fit, Next Fit, Best Fit Buddy System Binary Buddy, Double Buddy Segregated Free Lists Simple Segregated Storage, Segregated Fit Stephenson s Algorithm UAH 3 M. Rezaei

4 head Existing Memory Management Algorithms Sequential Fit Algorithms size address available Chunk tail ) 22 free(object x address 1010 size m alloc(64 bytes) 21 malloc(32 bytes) 16 bytes Memory overhead UAH 4 M. Rezaei

5 Existing Memory Management Algorithms Buddy System 64 bytes request 20 is satisfied 128 bytes 256 bytes 20 malloc(3 9 bytes) 21 malloc( 32 b ytes) UAH 5 M. Rezaei

6 calculate the index Existing Memory Management Algorithms Segregated Free Lists (Simple Segregated Storage) index size available chunks request is satisfied 20 malloc(29 bytes) UAH 6 M. Rezaei

7 Existing Memory Management Algorithms Stephenson s Algorithm head size s address available chunk s 2 = < s 1 s 3 = < s 1 20 malloc(70 bytes) s s bytes Memory overhead UAH 7 M. Rezaei

8 Existing Memory Management Algorithms Stephenson s Algorithm head malloc (70 bytes) size s address s = < s available chunk s 2 s s 3 = < s malloc(70 bytes) UAH 8 M. Rezaei

9 Existing Memory Management Algorithms Stephenson s Algorithm head size s address available chunk s s 2 = < s 1 s 3 = < s 2 s UAH 9 M. Rezaei

10 Existing Memory Management Algorithms Brief Comparison Storage Utilization Sequential Fits Segregated Free Lists Buddy System Execution Performance Buddy System Segregated Free Lists Sequential Fits UAH 10 M. Rezaei

11 New Memory Management Algorithms Address Ordered Binary Tree(ABT) head size maximum size (left subtree) available chunk address maximum size (right subtree) 20 malloc(70 bytes) 21 free(object x) size 20 and address bytes Memory overhead UAH 11 M. Rezaei

12 New Memory Management Algorithms ABT head size maximum size (left subtree) available chunk address maximum size (right subtree) 20 malloc(70 bytes) UAH 12 M. Rezaei

13 New Memory Management Algorithms ABT head size maximum size (left subtree) available chunk address maximum size (right subtree) malloc (70 bytes) request is responded UAH 13 M. Rezaei

14 New Memory Management Algorithms ABT head size maximum size (left subtree) = available chunk address maximum size (right subtree) free(object x) UAH 14 M. Rezaei

15 New Memory Management Algorithms ABT head size maximum size (left subtree) available chunk address maximum size (right subtree) UAH 15 M. Rezaei

16 New Memory Management Algorithms Segregated Binary Tree(SBT) <= 16 <= 32 <= 64 <= 128 <= 256 <= 512 > 512 UAH 16 M. Rezaei

17 Memory Management Techniques and <= 16 Intelligent Memories Memory management Functions IMEM 0 IMEM 1 IMEM n-1 CPU + $ UAH 17 M. Rezaei

18 Memory Management Techniques and Intelligent Memories Memory management Functions allocate( size ) Size indicates which binary tree to allocate the object from. free( address ) Address indicates in which Intelligent Memory chip, the object resides. Simple Segregated Storage can be mapped to IMEM chips as well UAH 18 M. Rezaei

19 Memory Management Techniques and Intelligent Memories The Problems Is each IMEM chip large enough to satisfy all the requests of its associated size What percentage of IMEM chip should be devoted to its simple processor (its logic) UAH 19 M. Rezaei

20 Memory Management Techniques and Intelligent Memories Follow Active Page Project (Oskin 98) 1 Gigabit DRAM for IMEM chips Sacrificing half of the chip for the logic 512 Kbyte Memory 256 Logic Elements Memory Management Technique that shows higher Storage Utilization is a better candidate to map to IMEM chips Then, for example, all the requests less than 16 bytes could be responded by only using one IMEM. UAH 20 M. Rezaei

21 Empirical Results Benchmark Description check Exercises the error checking capabilities of JVM compress Modified Lempel Ziv db Database Manager jack PCCTS tool javac Java compiler used in JDK jess Expert System mpegaudio MPEG Layer 3 decompressor mtrt Ray tracer (Threaded version) raytrace Ray tracer UAH 21 M. Rezaei

22 Empirical Results Segregated Binary Tree check compress db jack javac jess mpegaudio mtrt raytrace Average Average Number of Nodes Simple Segregated Storage UAH 22 M. Rezaei

23 Empirical Results Segregated Binary Tree Simple Segregated Storage 0 check compress db jack javac jess mpegaudio mtrt raytrace Average Total Number of sbrk system calls UAH 23 M. Rezaei

24 Conclusion and Future Work Address Ordered and Segregated Binary Tree New Memory Management Algorithms Both Simple Segregated Storage and Segregated Binary Tree are Suitable Algorithms to Migrate to IMEM Chips Significantly, Segregated Binary Tree Outperforms Simple Segregated Storage, in terms of Storage Utilization Migration of Memory Forwarding and Jump Pointers to IMEM chips UAH 24 M. Rezaei