Low Cost, High Performance, and Scalability:
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description
GUARANTEED!. Low Cost, High Performance, and Scalability: A New Approach to User-Level Distributed Shared Memory. OR YOUR MONEY BACK!!!. Patrick Anthony La Fratta WORTS 2005 15 December 2005. Programming Models: Message-Passing. Programming Models: Message-Passing. - PowerPoint PPT Presentation
Transcript of Low Cost, High Performance, and Scalability:
Low Cost, High Performance, and Scalability:A New Approach to User-Level Distributed
Shared Memory
Patrick Anthony La FrattaWORTS 2005
15 December 2005
GUARANTEED!
OR YOUR MONEY BACK!!!
Programming Models: Message-Passing
Programming Models: Message-Passing
Programming Models: Shared Memory
Implementing a DSM System at the User Level
Implementing the DSM ClientInitialization, Step 1:
Get size of shared memory segment.
Initialization, Step 2:Map n pages into local
memory.
Implementing the DSM Client
Initialization, Step 3:Take away all access privileges from the
shared segments.
Implementing the DSM Client
Initialization, Step 4:Set up the segmentation fault
handler.
Implementing the DSM Client
Implementing the DSM System
Application Reads Shared Address: Preview
Implementing the DSM System
Shared address read, Step 1:Application reads shared address.
Implementing the DSM SystemShared address read, Step 2:
Control transferred to seg-fault handler.
Implementing the DSM System
Shared address read, Step 3:Client contacts the server to get the page’s
data.
Implementing the DSM System
Shared address read, Step 4:Client grants read access privileges to
application.
Implementing the DSM System
Application Writes Shared Address: Preview
Implementing the DSM System
Shared address write, Step 1: Application writes shared address.
Implementing the DSM SystemShared address write, Step 2: Control transferred to seg-fault
handler.
Implementing the DSM SystemShared address write, Step 3:
Client contacts server to with write notification.
Implementing the DSM SystemShared address write, Step 4:
Server calls back all other copies of pages being written.
Implementing the DSM System
Shared address write, Step 5: Server indicates to client to proceed.
Implementing the DSM SystemShared address write, Step 6:
Client grants write privileges to application.
Implementing the DSM SystemShared address write, Step 7:
Later, the app detaches pages so others may use them.
Preliminary Results: All Pairs Shortest Paths
Note: Results matched for all test cases, and all runs completed successfully.
Exec. Time vs. Problem Size for Seq. and Parallel (with Row-wise Decomposition) Implementations of Floyd's Algorithm
0.00001
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problem size, n, # of vertices
exe
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Parallel, 2 PEs
System Profiling: All Pairs Shortest Paths
0.010
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8 16 32 64 128 256 512 1024 2048
Problem Size, n, # of Vertices
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Total Execution Time
0.001
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Problem Size, n, # of Vertices
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C1DT
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BWT
System Profiling: All Pairs Shortest Paths
System Modifications and Extensions
• Better understanding of the trade-offs in the design of the interface.
• Efficient synchronization primitives through extended memory semantics with full/empty bits.
• Server-side per-page locking and client-side full- page flushing.
* Speedups > 1! *
System profiles resulted in:
Performance Results: Speedup for Various Configurations
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256 512 1024 2048 4096 8192
Problem Size, n, # of Vertices
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256 512 1024 2048 4096 8192
Problem Size, n, # of Vertices
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Performance Results: Trends
Future Work
• Scalability: Enable clients to use more than one server.
• Peer-to-peer: Merge the server and client modules.
• Fault-tolerance: Checkpoint and Migration?
• Further testing: Implement and evaluate performance of other parallel applications.
Questions?
