System Research in MSRA Bingsheng He 1

Overview Research works within SRG – Debugging tools – Many-core operating system Personal research interests – Architecture aware systems Cooperation opportunities 2

Goal Debugging is challenging – Complex software: multi-threaded, distributed systems, legacy modules – Complex environment: hardware failures, network partition, disk error… Goal: make it easy to debug complex, distributed systems – Correctness bugs – Performance bugs 3

Our approaches Static analysis: enforce coding discipline – HangWiz (EuroSys’08): soft-hang detection – RegionWiz (PLDI’08): memory-region safety verification Runtime analysis – D 3 S (NSDI’08): distributed predicate checking – R2 (OSDI’08): deterministic replay to make bugs reproducible 4

Multi-core: the trend Chips with 2 or 4 cores are common Chips with 10~100 cores will appear within 5 years. [A. Agarwal 2007] Corollary of Moore’s Law 5

Problems in Existing OSes Share data structures protected by locks – Scheduling queues. [Gough et al. 2007] – Directory lookups. [Veal and Foong 2007] Codebases are too large and complex – Modifications are resource-intensive undertaking Corey: the first research prototype of redrawing the multi-core OS architecture 6

Corey Design Fundamental principle – Let applications/LibOS control sharing – Lock/share carefully /rarely – Use cores creatively Hardware Corey Mapreduce libOS Web Server libOS Mapreduce App Web Server App U K Interconnect C0 C1 C3 C2 Many-core 7

Architecture Aware Systems Processor aware systems – Cache conscious automata [ICDE’05, TKDE’06] – GPGPU [SIGMOD’07, SIGMOD’08] Disk aware systems – Flash-aware B+-tree [ICDE’09] Power aware systems 8

Cooperation Opportunities Co-application for project funds from MSRA – Funding promising research projects interested by the University and MSRA – Targeting at top-rank publications (usually) Internship/Visiting scholar – Exposing the students/faculties with the state-of- the-art research – Building a close relationship between MSRA and universities 9

Who we are Managers Zheng Zhang Lidong Zhou Staff – Zhenyu GUO, Yang MAO, Wei LIN, Xuezheng LIU, Ming WU, Haoxiang LIN, Bing Su, Bingsheng He – Interns (MIT, UCSD…) 10

Our extended family Lintao ZHANG (MSR-SVC) Junfeng YANG (MSR-SVC/Columbia Univ) Geoff Voelker (USCD) Frans Kaashoek (MIT) Close collaborators in China – HUST (P2P VoD, Storage) – Fudan (manycore) – Tsinghua (HPC) – SJTU (Model checking/verification) – BJU (P2P) – … 11

Q&A Thanks. 12