Dipankar's Home




My Current Work:

I am working on energy management in servers - primarily on the ability to actively manage energy consumption.
  1. Trending and control of energy consumption in servers
  2. Save energy through both fine grain and coarse grain consolidation

Right now I am working on primarily platform-level capabilities, but I am also working with a number of people to improve utilization of resources that consume power (CPU, memory, I/O) in future systems. Some of the initial discussions around these happened at Ottawa Linux Symposium 2008 - Power Management Summit. At the moment, we are pushing towards efficienty consolidating work into small number CPU packages through scheduer changes and letting other packages go to deep sleep longer.

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 Many of those patches are in mainline now, so they are just a historical reference.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.

My Earlier Works:

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. Some of my earlier work from a couple of years ago are - Lock-free file descriptor management patchset which is a rewrite of how we maintain the information about open files of a task in the Linux kernel. The new model keeps file information in a separate fdtable structure which is replaced by a new one when file information expands beyond its capacity. This allows atomic update and there by use RCU for lock-free look-up of file information. This eliminates the current overhead that posix threads incur (by sharing the file descriptor table and bouncing its lock cache line) on I/O compared to processes.

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.