Marek Olszew ski Saman Amarasinghe MIT CSAIL Commit Group - - PowerPoint PPT Presentation

Marek Olszew ski Saman Amarasinghe MIT CSAIL Commit Group

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Deterministic Multithreading

[ Vasudevan and Edwards]

Always-on Race Detection

[ Hans Boehm]

P L D I ` 9 F I T

3 Architectures Operating Systems

Tackling these ambitious challenges:

Applications

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Where we want to be

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Greatest invention since the transistor:

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OS-Top Boxes Application-Top Boxes

DynamoRIO Pin Valgrind

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Aikido VM

Adds per-thread page protection support to threads running in single address space Duplicates shadow pages: Makes it possible to cheaply detect which data each thread accesses

Page tables:

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Aikido VM

• Good for systems that instrument

accesses to shared data:

• Race Detectors
• Deterministic Multithreading
• STMs, TLS, etc…
• Currently conservative:
• Instrument all instructions that

m ight access shared memory

• Instead:
• Dynamically detect which

instructions definitely access shared pages, and instrument

• nly those

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Questions?

Aikido VM

http:/ / groups.csail.m it.edu/ com m it/

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Backup Slides

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Originally inspired by: Overshadow by Chen et al. ASPLOS ’0 8

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PetraVM Jinx

Uses a VM to transparently checkpoint and explore different interleavings of shared memory communication to try to trigger bugs.