Tue, 01 Dec 2009

Linux Next Graphing

A while back Rusty posted about graphing the size of the daily linux-next patches.

Since we are heading towards the merge window for 2.6.33 and hence sfr has been getting home later and later, I thought I'd take another look at it.

The dodgy script I've been using to create this is out here. This also creates the raw data file which is here.

You can see some periods where there was no linux-next release, like around the 2.6.27 release. You can also see that linux-next is never zero size. Either Linus doesn't take everything in linux-next, or new stuff for the following release is coming in before the last release is done with. sfr mentioned that there is some stuff in linux-next that's been in there for ages and hasn't been merged up to Linus.

There is a difference between how Rusty got his data and how I did. Rusty used the size of the bz2 patch out on kernel.org. These patches are against the release and release candidates (ie. against 2.6.30, 2.6.30-rc1, 2.6.30-rc2, etc). I'm using the linux-next git tree to determine how big linux-next is for that day. Since sfr bases linux-next off Linus' git origin each day, I take the difference between Linus' git origin and the linux-next release to determine the size. Since Linus' origin is at least as new as the RCs, my size is never larger than Rusty's. This is especially noticeable in the merge window (the ~2 weeks between the release and rc1). In the merge window, Rusty's size continues to grow until rc1 is released, but mine starts to go down almost immediately after the main release as Linus starts merging trees into his git origin and making life easier for sfr. Also, Rusty is using patch size (bz2 compressed) and I'm using the number of lines changed (insertions + deletions).

It seems that maintainers are working/merging new code constantly throughout the cycle. Ideally (yeah, coz I'm is the authority on this!), we wouldn't see a lot of new code hit linux-next just before the merge window opens as new code should hopefully be being tested at this point. If the rate of new code was slowing down before the merge window, we'd see the line flatten to horizontally before the release. I guess we're hacking until the last minute, who would have thought!?!? ;-)

The peaks of linux-next seem to be a reasonable predictor of the relative size of the following kernel release. ie. if linux-next is bigger, so is the following release, although it's not perfect (ie. 2.6.29 vs 32)
Release Actual line changes linux-next changes linux-next/Actual %
2.6.29 1879345 1222635 (peak at 2.6.28) 65%
2.6.30 1547035 1168031 (peak at 2.6.29) 76%
2.6.31 1419059 1118892 (peak at 2.6.30) 79%
2.6.32 (-rc8) 1618369 1247456 (peak at 2.6.31) 77%

These last two ideas are interesting to combine. When a release is delayed, it's resulting in more code for the following release, since code is being developed right up until the merge window opens. So delaying a release is double edged sword. It improves the current release (more testing/debugging), but makes the follow release bigger. If we were developing earlier in the cycle and then just testing as the merge window approached, we wouldn't have this phenomenon. I suspect this is already known, but hopefully this backs it up a bit.

I haven't attempted to confirm what Rusty noticed about hackers working more on weekends but if someone wants to analyse the raw data....

Since I've got this scripted up, so I'll endeavour to keep this graph updated out here.

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Wed, 30 Jan 2008

linux.conf.au 2008 Hackfest

Get your coding pants on because it's time for the linux.conf.au 2008 Hackfest.

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Fri, 18 Jan 2008

Source Control Rulage/Suckage Ratio

It's time to bring some real science into the source control debate. Google Rulage/Suckage ratio!

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Thu, 15 Mar 2007

FuckWits 1.0

People! Stop adding 2.0 to the end of names... Please!
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Wed, 22 Nov 2006


I've been helping jk with the simple but wonderful bitfield (me helping mostly equated to telling him what features I wanted, followed by him telling me he'd already implemented them and then laughing at me).
We now have bash completion, vim modes and Debian/Ubuntu packages which can be grabbed from here:
deb http://neuling.org/devel/bitfield/ ./
We are looking to improved the register database, so if you have any register definitions you'd like added, email jk or even better, grab the Mecurial tree and submit it as a patch.

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Wed, 25 Oct 2006

Telstra's Next G Questions

I got some responses to the Next G competition:

Did you know competition in telecommunications has been linked to cancer?

[ ] No

[ ] Yes, and I heard buying T3 shares can prevent it!

[ ] No, please tell me more.

Have you ever seen a grown man naked?

[ ] Yes

[ ] No

[ ] No, and stop calling me Shirly.

You are a large telecommunications wholesaler, a large telecommunications retailer of your own services, and have your origins in the regulatory authority designed to make sure you do the right thing. Most of your money comes from overcharging your customers for piddlingly small data comms services and denying wholesalers to the prices you charge your own retail outfit. The entire nation wants faster broadband access but you stand only to lose big gobs of money if you make it easier for people to move data around. What do you do?

[ ] Claim that installing faster broadband access would hurt shareholder value.

[ ] Pretend to be on the ball by talking about something completely different.

[ ] Try to sell the public another high-priced, low-bandwidth service.

[ ] All of the above.

[ ] Work with everyone else in the telecomms industry to give the public what they want, and stiff the Federal Government for the money.

N.B. Please only tick options with one letter.

How do you see life?

[ ] Like a movie.

[ ] Like a TV series.

[ ] Like a play.

[ ] Like a seance.

What is your ideal start to the day?

[ ] Finding out you've won a million dollars through your Next-G Mobile's new high-speed internet browsing capability.

[ ] Meeting your life partner through your Next-G Mobile's new high-speed internet browsing capability.

[ ] Making all your friends envious by showing them your Next-G Mobile, with it's new high-speed internet browsing capability.

[ ] Going for a forty-kilometer ride in driving rain and then eating a bowl of cold gruel.

What is your star sign?

[ ] The rutabaga.

[ ] The mump.

[ ] The hurdy-gurdy.

[ ] The quilt.

How many shares in Telstra do you already own?

[ ] 10,000 -> 39,999

[ ] 40,000 -> 87,624

[ ] 87,625 -> 274,999

[ ] Greater than 275,000

N.B. In order to proceed, you must own enough shares to qualify for this question.

Is the number of flavours to your liking?

[ ] Yes

[ ] No

[ ] I trust the computer implicitly.

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Telstra's Next G

Being the geek I am, I was interested in finding out what the hell this Next G stuff from Telstra was all about. So I search and find http://www.nextg.com.au.
Looks like a pretty simple page, with one obvious link to:
Ok, sounds good hopefully there'll be something in there...
To find out how Next G will benefit you, just answer a few simple questions (between 1 and 5). Hit the 'NEXT' button to proceed.
Bad sign, but let's persist... It's only 5 questions after all.

Question 1.

What best describes your needs today?

[ ] Personal

[ ] Business

Not too bad and I guess this may be useful technical information. I click Personal.

Question 2.

How young are you?

[ ] 18-24

[ ] 25-29

[ ] 30-34

[ ] 35-39

[ ] 40-44

[ ] 45-49

[ ] 50-54

[ ] 55-59

[ ] 60+

Humm, kinda wierd but ok. I click 30-34.

Question 3.

Please insert your postcode [ ]

Arrh, definitely useful technical information so they can work out coverage. Maybe this isn't going to be too bad

Question 4.

Which best describes you?

[ ] My friends' opinions are important to me

[ ] My main aim in life is to be a good parent and provide for my family

[ ] Both

[ ] Neither

Err... what the fuck?!?! I just want wireless broadband! I close my eyes, think of home and click Neither.

Question 5.

What do you seek in life?

[ ] Comfort and prosperity

[ ] Happiness and inner peace

[ ] Both

[ ] Neither

Err, ok... How about.. I seek Wireless broadbad!!!! Sounds crazy, I know!

Question 6.

Are you?

[ ] Male

[ ] Female

Err ok.. so this is question 6 of 5.. interesting, very interesting.

So, Rusty suggested it's time to run the Telstra Next G Stupid Question competition. Email me your suggestions for the questions Telstra should have asked, and I'll post them online. eg:

You are standing in a watch tower and Dubbya enters your gun sight. Do you:

[ ] Take out the Leader Of The Free World

[ ] Buy T3 shares

[ ] Buy T3 shares

[ ] All of the above

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Tue, 12 Sep 2006

Puzzle time..

I've not done a puzzle for a while and I heard this the other day. Apparently a common Google job interview question.

You have 8 balls, all of which are identical expect 1 slightly lighter than the other 7. You also have a balancing scales. Using the scales only twice, determine which of the 8 balls is the light one.

Email me if you have a solution/question. I'll post the solution in about a week.

Update: I got lots of responses to this puzzle. The solution is (I stole the best worded response, thanks Ian):

Keep two balls aside. Weigh three each in the scales. If the scales balance, it's one of the two spares. Balance them, and pick the lighter one. If the scales don't balance, compare two of the three balls from the lighter side. If those balance, it's the third ball.

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Sat, 02 Sep 2006

This is fun, but a big time sink...

Google Image Labeler. Cool idea. Reasonably simple and accurate way to categorize images. I wonder if they'll release the collected results for others to use as training data.

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Tue, 06 Jun 2006

Chinese Whispers

  • Sony presentation:
    Cell read bandwidth from GPU local memory is 16MBps
  • Inquirer:
    Cell read bandwidth from local memory is 16MBps
  • Slashdot:
    Cell read bandwidth from local memory is 16Mbps
  • IT industry:
    Cell is purple monkey dishwasher

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    Mon, 02 Jan 2006

    CControl Debain

    CControl has been Debianised. I'm hosting an apt repository at neuling.org. If you want to use it, add the following line to you sources.list (x86 only at this stage):
    deb http://neuling.org/ccontrol/ ./
    You'll then need to run ccontrol-init to create a default configuration file and then add /usr/lib/ccontrol to the start of your PATH to pick up the new gcc, cc, ld, make etc. (eg. export PATH=/usr/lib/ccontrol:$PATH)

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    Thu, 22 Dec 2005

    Why use ccontrol..

    ccontrol is great! Here are some reasons why (in dot points, 'coz everything is better in dot points!):
  • It's very easy to setup. It even does auto probing of your network to find distcc hosts.
  • You can use it to compile any package without the need to screw around with Makefiles etc. Just type make everywhere you want to compile
  • It's been tuned it so that interactive performance on your local machine is not compromised during compiles.
  • I used crosstool to install the 64 POWERPC GCC cross compiler on my x86 laptop. I didn't need to do anything special to get it to work under ccontrol, just downloaded crosstool and build as usual.
  • I can now build 64bit POWER Linux kernel on my laptop without playing with Makefiles or even having to specify any parameters to make (even ARCH=). This also uses distcc as you'd want. ccontrol works out what you want based on the directory name.
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