Session:The Kernel Report ELC 2012

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Session Details

ELC 2012
February 15, 2012
Jonathan Corbet
The Kernel Report ELC 2012
here (linux foundation) and here (free-electrons)
58 minutes


The Linux kernel is at the core of any Linux system; the performance and capabilities of the kernel will, in the end, place an upper bound on what the system as a whole can do. This talk will review recent events in the kernel development community, discuss the current state of the kernel and the challenges it faces, and look forward to how the kernel may address those challenges. Attendees of any technical ability should gain a better understanding of how the kernel got to its current state and what can be expected in the near future.


Jonathan Corbet got his first look at the BSD Unix source back in 1981, when an instructor at the University of Colorado let him "fix" the paging algorithm. He has been digging around inside every system he could get his hands on ever since, working on drivers for VAX, Sun, Ardent, and x86 systems on the way. He got his first Linux system in 1993, and has never looked back. Mr. Corbet is currently the co-founder and executive editor of Linux Weekly News; he lives in Boulder, Colorado with his wife and two children.



Transcribed by
Chris Dudding

0:00 - 1:00:

[ELC Slide - Thank you to our sponsors]

>> INTRODUCER: So, I'd like to welcome you all out to this year's Embedded Linux conference. Very happy to see you all here and I hope you're as anxious as I am.

We're.. well erm. anxious is not the right word but excited as I am about the great sessions we've got planned for this week. Um..

This is always erm.. the best part of getting ready for a conference is when you actually get the thing under way and there's been a lot of prep work behind the scenes and we're very excited to have you here and excited about the programme we've got.

[ELC Slide - Mobile App]

I've got just a couple of quick announcements I'd like to make:

First, about the mobile application so in the guide it talks about a mobile app um.. the actual name you look for in the marketplace is wrong in the guide

1:00 - 2:00:

You need to look under Linux Foundation conference. And that's available on the Android Market. There's actually a kind of a funny story why its not available for iPhone and that was because when it was first submitted to the iPhone erm. I don't know what they call their..

>> AUDIENCE: App Store

[Laughter] Well, so. Yes, thank you. It actually it was for.. It had Android listed in the description because it covers both conferences: Android Developers.. [rephrases] Android Builders Submit and ELC and they rejected it because of the word Android. So, go figure!

So, not for lack of trying. I'm sorry we don't have an iPhone app for you. Get yourself a more open phone! [Laughter]

[ELC Slide - Intel Atom Processor Giveaway]

Anyway, also I'd like to talk about this. So this um.. [holds Intel Atom development board] Ignore the antennas. Inside is a little development board

2:00 - 3:00:

that is being manufactured by Intel and it contains an Atom processor. Its actually called the.. I love Intel code names.. the board is called a Fish River Island 2 and its erm. E6XX Tunnel Creek Processor and they will be manufacturing these.. these are not available yet. They will be manufacturing 'em and sending them out to attendees. If you are interested in getting one.. we have.. unfortunately we don't have enough for everyone but what they are doing is they are taking proposals you can register at the Intel desk just outside in the lobby. And kind of just give an idea what you would plan to do with the board and the first 120 good ideas will get one shipped to you sometime in April or May. So, that's pretty nice. Let's thank Intel for that. [Claps] So that's pretty nice. Um.. So that's pretty cool

3:00 - 4:00:

Nice little development board for you [inaudible comment from audience] [laughs] No, too low.

and let's see I want to mention the YOCTO reception, hosted by YOCTO and Intel is reception tonight. Should be a lot of fun. Its over at the hiller aviation museum and there's a little.. cute little boarding pass thing you got talking about that also we've got little stickers done by jambe that you can get if you want to proudly proclaim that you came to ELC

and the last thing to do is to introduce our keynote speaker for this morning. So, I've known Jon Corbet for a number of years. He's kind of.. I don't know if this is the right term because he has no beard.. he's one of the grey beards in the Linux industry and an incredible incredible asset

4:00 - 5:00:

At these events it is very customary for us to put in a plug for and this event is no exception. In my opinion one of the premier sources for information about Linux, the Linux kernel and the industry and open source.

If you are not a subscribing member of, you should be one.. shame on you.. because this is an asset. Really a community asset that we should support and Jon very graciously accepted to give our kernel report and he'll tell us all about what's going on with the kernel in the last little bit and maybe a little bit about what's coming up in the future

So without further ado, let me introduce Jon Corbet.

5:00 - 6:00: [Slide 1 - The kernel report]

>> JON CORBET: Hi. Thanks a lot. Good morning everybody. How many of you have seen me give one of these talks before? [Laughter] A fair number.

[Slide 2 - The plan]

Well you'll be glad to hear I've reorganised it.

The plan remains the same, which is to look back over a years worth of kernel developments with an eye towards what's going on in the future. I've changed the way things are done. Hopefully it will work out well.

[Slide 3 - Starting off 2011]

We're actually going to start just over a year ago with.. at the beginning of 2011 we saw the release of the 2.6.37 kernel.

What better to start a new year than with a new kernel? This was a fairly big release with well over 11,000 changesets in it.

This kernel brought in the first of a set of scalability patches for the virtual filesystem layer which added a fair amount to the complexity of that layer but also if you had the right kind of workload brought about something of the order of 30% performance improvement if you were doing lots of opens and closes that sort of thing. So that was good to have.

Block I/O bandwidth controller.. its actually a second bandwidth controller working at a higher level in the I/O scheduler stack allowing

6:00 - 7:00:

the placement of absolute limits on block I/O bandwidth

Finally got some support for the point to point tunnelling protocol in the mainline kernel.

Basic support for the parallel NFS protocol and

Wakeup sources which is an interesting.. on its own wakeup sources is just an accounting mechanism for tracking devices in the system that can wake the system from a sleep state but its part of a bigger effort to replicate the android opportunistic suspend mechanism and provide an implementation of that mechanism that works well within the mainline kernel. So we are still seeing pieces of that going in and pieces of it under discussion but at some point we may have a solution for that

So that was 2.6.37 - a lot went in there.

[Slide 4 - What have we done since then?]

And a lot has happened since then. So what has gone on since 2.6.37?

We've made 5 more kernel releases. I can call them out as i come to them going on the year.

We've merged almost 60,000 change sets it was over the course of the last year. These have come from over 3000 developers and at this point we have over 400 companies that we can identify that have contributed to the kernel

7:00 - 8:00:

So, I've put up numbers like this before. We've seen them before.

We know at this point that the kernel is a very active, very fast moving project. Perhaps the biggest on the planet, hard to say and it continues to move on and it shows no real signs of slowing down

[Slide 5- February]

So February of 2011

[Slide 6 - Greg K-H quote]

One of the things that happened early on in february was a little note from Greg Kroah-Hartman congratulating ralink saying as you can see ralink has stopped dumping drivers on us and instead is now working on patching the driver that we already have in the upstream kernel and trying to make that driver support their new hardware this he said shows a huge willingness to learn how to work with the kernel community and they need to be praised for this change in attitude

This is..i mean its a nice note but there is nothing all that special in a way its something that we go through with a lot of companies they take a little while to figure out how to work with us and then they do

8:00 - 9:00:

and so we see a lot of progress as companies figure out how does mainline kernel process work, how can we get our code in there, why is it in our interest to do so and then they figure how to do it and they become part of the machine. And we see this happening over and over again

[Slide 7 - Employer Contributions]

So this seems a good as time as any to put up this slide. This is a variant of a slide that i've been putting up for a while showing the top contributors to the kernel over the course of the last year from the beginning of the 2.6.38 development cycle through the 3.2 release

So, we see as always, volunteers top of the list at just under 14%. The percentage of changes coming in from people working on their own time has actually slowly fallen over the years and why that is is hard to say. One could take a pessimistic view and say that the kernel is getting too big and too complex, the easy projects are done and so we are putting off our volunteers that way. On the other hand, one could look at this and one could say well anybody who has shown any ability to actually get code into the kernel in any kind of reliable way

9:00 - 10:00:

tends not to stay a volunteer for very long unless they really really want to because they tend to get buried in job offers.

so that of course is not going to be a bad thing.

other than that we see a lot of the same companies that we've been seeing for quite a long time

we can see companies that are not only competing fiercely in other areas of the market but in fact at this point they all seem to be suing each other elsewhere [Laughter] but they are still working together quite well at this level and um.. the situation hasn't changed a whole lot

but here's one change I want to call out

this is.. was.. alright.. we'll do it the old fashioned way. no we won't..

[Slide 9 - Kernel changeset contributions by employer]

speak to me.. come on.. um.. alright. well. this is the one i was going to get to eventually. um.. what is going on here.. alright.. we'll get there

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