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Revision 6 as of 2015-03-09 00:21:15
KernelNewbies:
  • Preeti_U_Murthy

About Me

I am a Linux Kernel Developer working at IBM, Linux Technology Center, India. I work in the area of CPU Power Management, specifically enabling deep CPU Idle states and improving the CPU Frequency subsystem on IBM POWER platforms. I have been involved in the discussions around Power Aware Scheduling in the kernel community where we are trying to improve the power efficiency of the kernel. Of late I have been reviewing patches around Dynamic Ticks and am keenly interested in the Full Dynamic Ticks Infrastructure.

Project Details

References

  1. The chapter on "Time Management" at http://www.e-reading.link/bookreader.php/142109/Professional_Linux_kernel_architecture.pdf

  2. https://www.kernel.org/doc/Documentation/timers/NO_HZ.txt

  3. Status of Linux Dynamic Ticks: http://ertl.jp/~shinpei/conf/ospert13/slides/FredericWeisbecker.pdf

Tasks

The following tasks are listed in the increasing order of complexity.

Please note that the same task can be claimed by more than one intern

To begin with, download the vanilla kernel.

Challenge Problem 1

Configure two different kernels, one with NO_HZ_IDLE=y and another with NO_HZ_IDLE=n. Boot each of these kernels and perform the following test on each.

Download the ebizzy benchmark from http://sourceforge.net/projects/ebizzy/. Compile and run this benchmark a few times. You must see consistent results. Record the number of records read. Download the powertop utility and run it while running the benchmark. Record the %time spent in different idle states.

Now compare the records read and %time spent in different idle states in both the above kernels and conclude as to which of the two has a better power efficiency.

Challenge Problem 2

git://git.kernel.org/pub/scm/linux/kernel/git/frederic/dynticks-testing.git. Clone this archive.

Run this on two different kernels. The first kernel should be compiled with CONFIG_NO_HZ_IDLE = y in the config file and the second kernel compiled with CONFIG_NO_HZ_FULL = y.

This page will be updated with more tasks soon.

Contact Info

You can email me at: preeti@linux.vnet.ibm.com

My IRC handle is preeti

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