1. 6/10/2005 FastOS PI Meeting/Workshop K42 Internals Dilma da Silva for K42 group IBM TJ Watson Research

2. 6/10/2005 FastOS PI Meeting/Workshop K42 Goals Scalability Flexibility/customizability Framework for OS research –Linux API and ABI and kernel module compatible –Available to collaborators under LGPL Maintainability/extensibility

3. 6/10/2005 FastOS PI Meeting/Workshop Structure OS function in user-level library –examples: timers, thread library... –allows OS services to be customized for applications with specialized needs –avoids interactions with kernel/servers, reduces space/time overhead in kernel/servers Object-oriented design at all levels Micro-kernel Servers Linux emulation OS lib Application Linux emulation OS lib Application

4. 6/10/2005 FastOS PI Meeting/Workshop Object-oriented design

5. 6/10/2005 FastOS PI Meeting/Workshop OO Design: MM Objects Process FCM FR HAT Region FCM: File Cache Management FR: File Representative HAT: Hardware Address Translation

6. 6/10/2005 FastOS PI Meeting/Workshop Process FCM FR Region Process FCMFRRegion

7. 6/10/2005 FastOS PI Meeting/Workshop Region OO design enables specialized implementations Specialization and Clustered Objects

8. 6/10/2005 FastOS PI Meeting/Workshop Clustered object infrastructure Per-processor level of indirection avoids any centralized bottleneck Provides library to simplify distributed implementation –Caching of local state –Incremental distribution of services –DHash Focus on locality! Read-Copy-Update techniques –Use non-blocking synchronization –Avoid locking hierarchies

9. 6/10/2005 FastOS PI Meeting/Workshop Hot-swapping change one system component/type for another without bringing system down potential uses –scalability –performance –monitoring –extensibility –testing Dynamic update: system availability

10. 6/10/2005 FastOS PI Meeting/Workshop Hot-Swapping/Dynamic Update Depends on: –object-oriented structure of system –technology to establish a quiescent state –level of indirection Implementation has no additional overhead –when not swapping an object –for objects not being swapped Limitations: –is not instantaneous –initial prototype –Current work: coordinated swapping, interface changes, external policies...

11. 6/10/2005 FastOS PI Meeting/Workshop Independent workloads

12. 6/10/2005 FastOS PI Meeting/Workshop More hot-swapping Adaptive paging Adaptive file imp.

13. 6/10/2005 FastOS PI Meeting/Workshop Memclone benchmark: Memory intensive parallel application

14. 6/10/2005 FastOS PI Meeting/Workshop Performance monitoring unified cheap scalable non-blocking tracing infrastructure for correctness and performance debugging key parts of design transferred to LTT post processing tools easy to develop: lock contention, sampling, time breakdown, visualization, caching effects,... in final numbers, disabled, but only %1.6 difference UP and 24 way

15. 6/10/2005 FastOS PI Meeting/Workshop Status http://www.research.ibm.com/K42 dilmasilva@us.ibm.com