Blog from a standalone client

I am giving a shot at posting this blog entry from a standalone client. Like it very much, quite cool and awesome.

I also like that I can bold, italicize, underline, increase font size,

1. number items
2. Who is number two?

• bullet them
• bullets, like sub-bullets

So much more easily. There is also tables, pictures, etc, but I’ll get to them slowly.

Open source blows my mind again

I wrote the configuration parser for libcg sometime back. Dhaval helped make significant improvements to it as well. At the time we wrote it, I had imagined we would probably create about 20 or so groups, but I planned ahead and "hard coded" the limit to create 1024 groups. How forward thinking of me :)

This morning I got a message in my inbox that said

"I'm using cgroups for lots and lots of users per server (2.000 or more).The problem is, I'm using one cgroup per user (for memory reasons)." See http://permalink.gmane.org/gmane.comp.lib.libcg.devel/1737

I was surprised to see that someone wanted to create so many cgroups, my first reaction was "Oh! my god" I hope we don't have a major bug in functionality or scalability.

I looked at the code and asked for counter that controls maximum number of groups to be scaled to something like 2048, hoping that the code would work, here is what I heard back.

"Yes!!! Thank you very much.. Its working now.. 37 thousand lines, 1400users (one cgroup for each user) :D Server is up and running now :D". See http://permalink.gmane.org/gmane.comp.lib.libcg.devel/1744

They use memory cgroups in their setup both hard and soft limits, so kudos for testing the whole solution. I never expected that we would be able to parse those many lines and support that sort of a configuration. This is where open source wins, I was able to provide a solution in seconds and I am hoping more feedback from the end users will help drive all the technology they use and I develop in the right direction. Had our software not worked well, we would have fixed it to enable the end user at the earliest.

Open Source blows my mind again and again!

Published an article in Linux For you

You can see the abstract below

Developers Introducing Kernel Samepage Merging The motivation of KSM comes from the observation that on a large machine running several virtual machines (potentially running the same OS), there are a number of duplicate pages, each consuming a page of memory in the hypervisor.

The URL for the magazine is http://lfymag.com/currentissue.asp?id=13

Go rush and get the January 2010 copy, comments, feedback, criticism always appreciated!

FOSS.IN 2009 was great

I am delinquent in reporting about my FOSS.IN experience this year. Nevertheless, better late than never! My summary goes, the good, the awesome, the excellent and the let-downs. For the photo stream check out "foss.in/2009" tag on flickr

The let-downs

1. There were very good talks, I spoke as well (see http://foss.in/2009/schedules/talkdetailspub.php?talkid=15), but I was surprised to see people who had never contributed code, presenting, even though that is something that FOSS.IN was trying to move away from.
2. Atul stepped down as the organizer or key-organizer of FOSS.IN. We've had some interesting discussions on the mailing list, I'll certainly miss those
3. Stalls - the stalls from Nokia and some of the student stalls were awesome, I was hoping to see some key innovative work happening
4. Goody bag - I did not get my goody bag, I asked early and I was told to come at the end, but I was told they ran out :( I missed out on the mug I admire soooooo much
5. FOSS.IN almost seeming like FOSS.DE (we need a stronger rotation policy :), just kidding on this one)

The good

1. I loved the spirit of FOSS.IN
2. Loved the environment and speaking to the volunteers
3. Pulseaudio, I typically and still to some extent don't like Pulseaudio, but the technology and the architecture I learnt from the learned, seem very impressive
4. The hobby electronics group and their project

The excellent

1. The workouts were excellent, the BoFS and many workouts had more focus
2. The rock music by the Raghu Dixit Project
3. Met some free lancers using Linux, they did not have stalls, but their projects sounded very exciting
4. The participants were serious about what they wanted to work on, which is very exciting to see
5. Networking and spending time with people

The awesome

1. The food arrangement, Hallimane

Hmmm.. Did I just put my neck out and at the same time be lazy? BTW, I wrote my Linux For You article while attending the conference :)

Some photos from FOSS.IN 2009 (more to come)

I've not yet had the time to sit down and write a report and my experience, but here are some photos

From James Morris at Flickr

From Kishore Bhargava at Flickr

The entire set that Kishore has can be accessed here

Thought for the day in Hindi

जो याद नहीं उसे भोल गए हम
जिसे भूल गए उसका नहीं गम!

Gops views on Mumbai 26/11

Well worth a read! We've had lot of heros, lets remember and pray for them, the victims and their families and that such things don't repeat themselves anywhere in the world.

Smooth upgrade to F12

My first post after the upgrade. The upgrade sailed through smoothly and I got back the packages I had to uninstall. The first issue I faced was the nomodeset issue. X would not recognize any resolution beyond "800x600", I had to pass nomodeset as kernel boot parameter to get my original resolution back.

I was also happy to see my back for resource counter scalability included in F12
(run rpm -q --changelog kernel | less)
* Mon Oct 12 2009 Kyle McMartin 2.6.31.4-75.rc2
- improve-resource-counter-scalability.patch: Fix scalability issues
on big machines, requested by prarit.

I am all set to sail, kudos to those who helped make Fedora and especially the upgrade path so smooth.

Upgrade Journey to Fedora 12

After reading the ever so useful YumUpgradeFaq, I've started upgrading my system from F11 to F12. I had some scarifies to make along the way, I had to remove about 100 of my favourite RPMS, so that the upgrade starts

yum finally told me...

Transaction Summary

=======================

Install 238 Package(s)

Upgrade 4512 Package(s)

Remove 4 Package(s)

Reinstall 0 Package(s)

Downgrade 0 Package(s)

Total download size: 5.0 G

Is this ok [y/N]:

Wish me luck!

Fedora 12 is out

I use Fedora on my desktop, now more than ever. I am currently well setup on Fedora 11, with 3D graphics (yeah, I can get Secondlife, google earth, etc to work with great speed) setup. Setting up 3D graphics was not easy (but that should be another blog entry. I also have my favourite sound system ALSA setup. I could never get used to Pulseaudio or get it to work the way I like. I am still trying to get webgl to work on my browser. The features in Fedora 12 are too tempting and of course I am already using some of the latest features via rawhide.

I guess its time to plunge into Fedora 12! Do take a look at the release tour of Fedora 12.

Thought for the day (Hindi)

मैं अकेला ही चला था जानिब-ऐ-मंजिल मगर, लोग साथ आते गए और कारवाँ बंता गया

मजरूह सुल्तानपुरी

Great Knock Dravid!

(From: cricket.yahoo.com)

Todays knock by Dravid's got to be the best I've remembered from anyone in a long long time. I've witnessed the record breaking knock with Laxman to help India win against Australia in India, the 200 odd to help India win against Australia in Australia.

I loved this one because of the determination and absolutely wonderful confident stroke play. This knock also got Dravid in the 11,000+ squad (only the 5th cricketer to have that honour). Bravo on the six, the quality of shots and the confidence. Keep the aggression coming Dravid! I love it!

Interesting memory cgroup controller links

Here are some interesting links on memory cgroup that I found online (NOTE: I've not referred to my own papers)

1. http://www.dmtf.org/svm09/presentation/Corset_Service-oriented_Resource_Management_System_Linux.ppt
2. http://www.socallinuxexpo.org/scale7x/sites/scale7x.socallinuxexpo.org/files/openvz-scale7x-resource-management_0.ppt
3. http://en.opensuse.org/Cgroup
4. http://elinux.org/Memory_Management
5. http://tree.celinuxforum.org/CelfPubWik/ELC2009Presentations?action=AttachFile&do=get&target=celf_mem_notify.pdf
6. http://www.xtreemos.eu/publications/project-deliverables/d2-1-7.pdf
7. http://siena.linux.it/linuxday09/presentazioni/andrea-righi-linux-kernel-hacking-process-containers.pdf
8. http://www.linux-foundation.jp/uploads/seminar20081119/CgroupMemcgMaster.pdf
9. linuxplumbersconf.org/2009/slides/Dave-Hansen-oom-v3.pdf

NOTE: This is just a partial list of references.

Bangalore book fair 2009

The Bangalore Book Fair has started today at Palace grounds and I happened to visit today. With close to 330 stalls, I was awed by all the books and publications present. I had two clear priorities

• Technical books
• Childrens books

On the technical front, I purchased





It was really nice to see a good number of exciting books for children, I even managed to find some interesting gifts for children I know.

I'd highly recommend visiting the fair, the last day is November 15th

Thought for the day

Happiness is when what we think, what we say and what we do are in complete harmony

Mahatma Gandhi

Arguing about OS'es

Gopal and I argued about Linux, Windows and browsing (nothing out of the ordinary though, we kill time in arguments and we've mastered that art). I thought I'd share what the stats look like for visitors on my blog. If you are worried about being profiled, don't worry, no personal information is stored by me! The data is from sitemeter and blogspot (If you are too concerned, you can start using the "Private browsing" or Incognito Windows)

Browser Share

Operating system share

FOSS.IN first shortlist

The shortlisted talks, workouts, project of the day, etc are announced. This year seems to be quite interesting with several kernel talks selected. I am looking forward to the Pulseaudio, security, S.M.A.R.T., kernel, gnome, GSM/Telecom, Haskell talks. I wish to attend them all assuming there will be no conflicts :)

Exponentiation

There are several well known exponentiation algorithms, but this one caught my eye, specifically due to its application in the Rabin-Miller primality test. Here is the math, the algorithm will follow later

Let the problem be rewritten as raise x to the power n. Let us convert n to binary


Where b0, b1, b2.. bk is the binary representation. Now lets rewrite x to the power n as

This in turn is equal to


The trick is to note that we need to compute even powers of x and determine b0, b1, .. bk. A simple trick is to, check if b0 is odd or even, if it is odd, multiply the current temporary value with x, if it is even, skip b0, but keep squaring the current exponent. Note we keep shifting n right, so that b1, b2,.. ,bk move to position b0 eventually.

Here is the algorithm from Sahni's textbook

def exponent(x, n):
 m = n
 expx = x
 power = 1

 while (m > 0):
     while ((m % 2) == 0):
         expx = expx * expx
         m = m >> 1

     m = m - 1
     power = power * expx

 return power

FOSS.IN posters are out

This is some of the best creative work I've seen (in terms of conference posters and getting the message out). All of this is released under CC. Excellent work guys! I am reproducing them below, the original post is at Posters! Posters! We need them, crave them

A consumer complains

I recently bought a new laptop and the display went bad in less than 15 days. I eventually got it back with the LCD replaced, but my experience at the customer service was horrible and I complained. Here is the letter I wrote, I am hoping that [company] will wake up and take notice. Customer service offered elsewhere (outside India) seems to be much more superior with value for customers.

My experience with [company] today was one of the worst I've had with any product support. I visited [service center] to repair my 15 day old laptop, the display had stopped working. I found that the front desk person opened my laptop without using any static protection mechanism, which I escalated all the way to [somename] (Customer Service Head). I asked for a letter of apology for not following prescribed procedure. [somename] told me it is a human error and I need to ignore it and stop interfering with how [company] service people work (I as a customer was going beyond my boundaries and interfering with their day to day work). After my complaint, the other people started doing the right thing, the local manager said that his employees were tired and just had lunch (hence the error). If [company] can void my warranty (even for opening my laptop, even though I did not (just hypothetically)), why is it OK for [company] service people to *NOT HANDLE* my laptop carefully.

Clearly I am very disappointed and want to see justice done in this matter. All I want so far is a letter of apology for not handling my product and a guarantee that their action has not damaged my laptop

Do you have any experiences to share? Consumer rights are taken for granted and I wish we could be more empowered to take stronger action.