#format wiki
#language en
== 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
 1. https://www.kernel.org/doc/Documentation/timers/NO_HZ.txt
 1. 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:

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 the test on two different kernels. Boot the first kernel, compiled with CONFIG_NO_HZ_IDLE = y in the config file, while boot the second kernel 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