Dipankar's Home




My Current Work:

I am currently working on several projects that lead to better cloud experience on IBM OpenPOWER servers. Some of the areas of interest are -
  1. Platform insights for cloud - Using non-intrusive hardware instrumentation for better insights in cloud services and applications. Some of the related work is happening in Opentracing, perfevents and related kernel work here.
  2. Persistent memory - enablement and exploitation of pmem
  3. UEFI+ACPI for OpenPOWER - We are experimenting with TianoCore on OpenPOWER servers and hopefully have something for the OpenPOWER community to play with. We have done some of work on a basic ACPI implementation as well.

My Earlier Works:

In the past, I have also worked on
  1. Co-operative energy management on IBM servers where operating systems co-operate with underlying platform (hypervisor, firmware, hardware) to provide best energy benefits. I have been involved in power-aware scheduling (see OLS 2008 / LPC 2010 papers) as well as HW/SW co-design of power management features in multiple generation of Power processors.
  2. Scalable kernel primitives - mainly the first implementations of Read-Copy-Update for Linux one of which was subsequently merged into 2.5.43 kernel. For more up to date information on RCU, see Paul McKenney's RCU page.
  3. Scaling Linux kernel using lock-less RCU algorithms - VFS dcache, Lock-less IPV4 route cache, Lock-less file descriptor management
  4. Various odd ball kernel development stuff - fget/fput_light, resource partitions in Linux and using it to support hetergeneous workloads, smptimers.
My Linux kernel patches can be found here. Many of those patches are in mainline now, so they are just a historical reference. I intend to upload lot of the experimental versions of my earlier work - specially various Read-Copy Update implementations there. Hopefully, as soon as I get time to sort to piles of old patches.

I did most of the original Read-Copy Update synchronization primitive deveopment work in Linux between 2001 and 2004 along with Paul McKenney. It was included in the mainline Linux kernel in 2003 and subsequently I worked on using RCU to scale some of the cache lookups in the Linux kernel.

My current publications:

  1. P. R. Panda, M. Jain, A. Verma, D. Sarma, V. Srinivasan Power Supply Efficiency Aware Server Allocation in Data Centers 2013 26th International Conference on VLSI Design and 2013 12th International Conference on Embedded Systems IEEE Explore
  2. D. Dharwar, S. Bhat, V. Srinivasan, D. Sarma, P. K. Banerjee Approaches Towards Energy-Efficiency in the Cloud for Emerging Markets, 2012 IEEE International Conference on Cloud Computing in Emerging Markets (CCEM), IEEE Explore
  3. V. Srinivasan, D. Sarma, V. Srivatsa, G. Shenoy, S. Siddha Energy aware task and interrupt management, Proceedings of Ottawa Linux Symposium, Ottawa, July 2008. pdf
  4. P. McKenney, I. Molnar, S. Bhattacharya, D. Sarma, Extending RCU for Realtime and Embedded Workloads, Proceedings of Ottawa Linux Symposium, Ottawa, July 2006. pdf
  5. Ravikiran Thirumalai, Dipankar Sarma, Manfred Spraul, Ho Hum, Do We Need Another Dynamic Per-CPU Allocator ?, Proceedings of Ottawa Linux Symposium, Ottawa, July 2005. pdf
  6. Paul E. McKenney and Dipankar Sarma, Towards Hard Realtime Response from the Linux Kernel, Proceedings of Linux.conf.au, Canberra, April 2005. pdf
  7. Dipankar Sarma and Paul E. McKenney, Issues with Selected Scalability Features of the 2.6 Kernel, Proceedings of Ottawa Linux Symposium, Ottawa, July 2004. pdf
  8. Dipankar Sarma and Paul E. McKenney, Making RCU Safe for Deep Sub-Millisecond Response Realtime Applications, USENIX, Boston, June 2004. pdf
  9. Andrea Arcangeli, Mingming Cao, Paul E. McKenney and Dipankar Sarma, Using Read-Copy-Update Techniques for System V IPC in the Linux 2.5 Kernel, USENIX, San Antonio, June 2003. pdf
  10. Paul E. McKenney, Dipankar Sarma, Andrea Arcangeli, Andi Kleen, Orran Krieger, Rusty Russell, Read Copy Update , Proceedings of Ottawa Linux Symposium, Ottawa, June 2002. pdf
  11. Hanna Linder, Dipankar Sarma and Maneesh Soni, Scalability of the Directory Entry Cache, Proceedings of Ottawa Linux Symposium, Ottawa, June 2002. pdf
  12. Paul E. McKenney, Jonathan Appavoo, Andi Kleen, Orran Krieger, Rusty Russell, Dipankar Sarma and Maneesh Soni, Read-Copy Update, Proceedings of Ottawa Linux Symposium, Ottawa, July 2001. pdf



My Other Interests:

Disclaimer:

Opinions here are solely mine and not necessarily of my employer.