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

Marek Olszew ski Saman Amarasinghe MIT CSAIL Commit Group

Deterministic Multithreading [ Vasudevan and ? ? ? ? ? Edwards] ? ? ? Always-on Race Detection P L D I ` 0 9 [ Hans Boehm] 2 F I T

Tackling these ambitious challenges: Applications Operating Systems Architectures 3

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Where we want to be 5

Greatest invention since the transistor: 6

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DynamoRIO Pin Application-Top Valgrind Boxes OS-Top Boxes 8

� � Adds per-thread page protection support to threads running in single address space � � Duplicates shadow pages: Aikido VM Page tables: � � Makes it possible to cheaply detect which data each thread accesses 9

� � Good for systems that instrument accesses to shared data: � � Race Detectors � � Deterministic Multithreading � � STMs, TLS, etc… Aikido VM � � Currently conservative: � � Instrument all instructions that m ight access shared memory � � Instead: � � Dynamically detect which instructions definitely access shared pages , and instrument only those 10

Questions? Aikido VM http:/ / groups.csail.m it.edu/ com m it/ 11

Backup Slides 12

Originally inspired by: Overshadow by Chen et al. ASPLOS ’0 8 13

PetraVM Jinx Uses a VM to transparently checkpoint and explore different interleavings of shared memory communication to try to trigger bugs. 14