LJ Archive


diff -u: What's New in Kernel Development

Zack Brown

Issue #136, August 2005

Linux kernel development was thrown into chaos recently, when Larry McVoy finally decided to pull the free-of-charge BitKeeper license as he has threatened many times to do. But within days of the event, Linus Torvalds and a horde of contributors had written an acceptable alternative, entirely from scratch. The git filesystem is Linus' brainchild, a low-level, extremely fast content tracker that appears to be almost completely alien to existing version-control ideas. Virtually opaque, it is intended to exist beneath a layer of scripts that make use of its various services. Anyone can script a new git user layer on top of the basic system. In fact, Petr Baudis has been working with tons of folks on Cogito, a git front end that looks to be Linus' choice for ongoing kernel development. Many Web interfaces and other auxiliary tools also are springing into existence at a rapid rate.

H. Peter Anvin has been keeping kernel.org up to date with all the latest git repositories, arranging for hosting services and generally tending house. Recently, however, kernel.org began yet again to bog down with the tremendous bandwidth demands from all over the world. This time, Hewlett-Packard was the one to charge to the rescue, donating two powerful computers. kernel.org will now operate as a DNS round-robin between both. This has reduced site latency significantly, and it drastically sped up upload time for site contributors as well. At last report, nary a glitch remained, although the round-robin does make it more difficult to derive network traffic statistics.

Joel Becker has created ConfigFS, another interface into kernel internals. The goal this time is to create something scriptable and completely readable. But with SysFS already in existence and performing a similar function, it's unclear whether ConfigFS will represent a true advance or just another addition to the mess. All of these filesystem-based interfaces have been born out of a desire to recover somehow from the ProcFS, /dev, ioctl nightmares Linux inherited from its great progenitors. But if these new alternatives themselves are not sufficient, SysFS, udev and now ConfigFS become only more legacy cruft to be hated by kernel developers for years to come.

The FUSE (Filesystem in USErspace) developers either are cleaning house or making a new mess. Miklos Szeredi posted some patches to make the user interface compatible between 32-bit and 64-bit modes of operation, on systems that supported both modes. Among its various benefits, the patch breaks the backward compatibility of the user interface. With FUSE already in Andrew Morton's -mm kernel tree, this patch may be one painful yet required step along the bridge into the official kernel; or it may be a descent into breakage, on the way out of Andrew's tree altogether. Time will tell. At the last previous report, the FUSE developers were making good progress toward answering some of Linus' harsher objections, and he was no longer so completely dead set against even the idea of a user-space filesystem.

After a public discussion between the two groups of developers on the open-iscsi and linux-iscsi projects, they have decided to merge into a single project. For technical reasons, both groups have agreed to start from the open-iscsi codebase, because of that project's optimized input/output paths and the well tested iscsi-sfnet components for the control plane and user-space components. The open-iscsi Subversion repository will continue to be used, at least for now. This unification of two projects working toward the same goal is excellent. Hopefully most of the linux-iscsi group will remain and continue to contribute; and their previous accomplishments will continue to be recognized, in spite of the migration to a new codebase.

Randy Dunlap is leading the charge to reorganize the kernel's networking configuration options. This has been an ugly task to consider, because in many cases it is not at all clear how best to organize the hierarchy. Is something a driver, or is it a protocol? Should all drivers be grouped together, or is it all right to group some drivers with a specific related subsystem? Randy bit the bullet and made a first pass at answering some of these questions and was quickly joined by several other folks. With much wrangling, soul-searching and a little guesswork, an entirely new landscape of network configuration seems to be forming gradually. We should expect to see portions of this landscape with periodic minor earthquakes in upcoming 2.6 releases.

Graphviz: www.graphviz.org

Don Marti

Issue #136, August 2005

I don't know about the rest of you, but I think best when I'm in front of a whiteboard drawing boxes and arrows. However, when it's time to put the idea up on a Web site, it's either upload huge photos of the whiteboard or spend hours dragging little boxes and arrows around in some GUI application. Graphviz to the rescue. I made this diagram in 15 lines of easy markup (yes, -> makes a line with an arrow) and converted it with one command. Multicolored boxes and lines take just a little more time with the on-line docs.

Graphviz really shines when it's time to generate big graphs from your own software. No matter how complicated a structure your program spits out, Graphviz turns it into a readable layout. See the Web site for examples.

Inside Talk

Doc Searls

Issue #136, August 2005

The best cases for Linux and open source in business often come from the resourceful people who put it to use there. What they provide are patches of wisdom that add to everyone's understanding. Eventually, resistance becomes futile because the advantages are understood too well. Here are three such “patches” from comments to just one Linux Journal on-line article:

With GNU/BSD licensed software at least, the receiver of the codebase is left in complete control. Even Microsoft could grab a copy of the code and configure/support it the same as with the Windows codebase. There's no corporate competition from OSS/Free software, just service companies that sell packages including it. —Chris Bergeron of pcburn.com.

In my experience, the main reason for buying into open-source projects goes far beyond “wanting something the market doesn't offer”. It's more about servicing business needs quickly. Who can wait for a vendor to respond to a request, when it's so much easier to take pre-existing OSS systems or code and improve them slightly to solve your particular problem? With ever-decreasing time frames, OSS makes the impossible possible. —Dave Moskovitz of www.thinktank.co.nz/dave.

For an IT professional, it often takes less time to install and configure an open-source package than to get approval to “buy” (actually, enter into a license for) a proprietary one. Transaction costs aren't just between vendor organization and customer organization—they're within organizations. —Anonymous

Source: “Getting Flat, Part I”: www.linuxjournal.com/article/8251.

LinuxFest 2005

Steve Hastings

Issue #136, August 2005

LinuxFest Northwest, the largest users group conference in the Pacific Northwest, was held again in Bellingham, Washington, 20 miles south of the Canadian border. Among the presenters was Google's Chris DiBona, shown here updating the audience on code.google.com, the portal site for the company's open-source projects.

LinuxFest Northwest was put on by the Bellingham Linux Users Group and six other groups, and hosted by Bellingham Technical College (BTC). As in previous years, LinuxFest was free of charge and open to all; an estimated 1,000 people attended.

More than 40 presentations covered topics from general interest to advanced systems administration. Presenters included people from IBM, Novell, RealNetworks, the Linux Professional Institute, the X.org Foundation and the Ubuntu Project.

The BTC Chefs Club served a grilled salmon lunch and espresso drinks.

The exhibits room included Google recruiters, some users groups, some free software projects, such as Ubuntu Linux and MySQL, and even the Seattle BSD users group.

For the second year, Chuck Wolber hosted the “Alpha Geek” trivia contest, which was a great deal of fun. The day finished with the annual fund-raising raffle. Several thousand dollars' worth of donated prizes included server hosting services for up to a year.

On the Web

Cast Your Final Votes in the 2005 Readers' Choice Awards

As you all know by now, we've made some changes to how we're running the Readers' Choice Awards this year so that our readers are more involved every step of the way. By the time you read this, the final ballot—determined by your write-in nominations and first-round voting results— will be available on the LJ Web site (www.linuxjournal.com/article/8272). Final votes will be accepted during the entire month of July, and the winners will be announced in the November 2005 issue of Linux Journal. As the name says, these are the Readers' Choice Awards, so get on over to the Web site, check out the final ballot and send us your votes!

For complete information, details and dates regarding the 2005 Readers' Choice Awards, read “New Procedures for 2005 Readers' Choice Awards” (www.linuxjournal.com/article/8192).

As you'll see in this month's article “Porting LinuxBIOS to the AMD SC520”, the port itself is an ongoing job. Author Ronald G. Minnich says, “The Porting article in issue 136 doesn't tell the whole story! Join us on the Web as we finish the port to the AMD SC520, dodging hardware glitches and software bugs as we go.” To follow along as the Cluster Research Team at Los Alamos National Laboratory continues its port project, head on over to the LJ Web site and read “Porting LinuxBIOS to the AMD SC520: A Follow-up Report” (www.linuxjournal.com/article/8310).

Whether you've built your Ultimate Linux Box, or if you're trying to get maximum speed out of a lesser machine, it's time to set it up for optimum speed for desktop applications. In a series of articles on “Optimizing Desktop Performance”, Tom Adelstein covers desktop performance tweaks from simple tools such as hdparm all the way up to a script that will make OpenOffice.org stay in memory and start more quickly when you open a document. Follow along with the comments and get some ideas there too (www.linuxjournal.com/article/8308 and www.linuxjournal.com/article/8317).

DIY Swapfest On-line

Doc Searls

Issue #136, August 2005

DIYparts.org is what Christian Einfeldt calls “a bazaar where people can develop connoisseurship around putting open-source software on old but useful boxes, thereby keeping them out of landfill”. Christian is the filmmaker behind the Digital Tipping Point documentary, and he co-created DIYparts.org with Adam Doxtater of Mad Penguin. Think of DIYparts.org as a swapfest for used gear of all kinds—from cases and motherboards to drives, monitors, racks, controllers, video cards, interface cards, PDAs and much more. See diyparts.org, www.digitaltippingpoint.com and madpenguin.org.

They Said It

But how many people pay attention at conferences any more anyway? I'm thinking about submitting “Live Demo of a Microwave Oven Modified To Run With The Door Off: The Conference Talk That You Wi-Fi Addicts Will Actually Pay Attention To”.

—Don Marti, on the linux-elitists mailing list

In fact, the business population was as likely as the prison and psychiatric populations to demonstrate the traits associated with narcissistic personality disorder: grandiosity, lack of empathy, exploitativeness and independence. They were also as likely to have traits associated with compulsive personality disorder: stubbornness, dictatorial tendencies, perfectionism and an excessive devotion to work.

—Belinda Board, in the New York Times, May 11, 2005 (www.nytimes.com/2005/05/11/opinion/11board.html)

We have a wonderful environment of friendly and collaborative competition, and have avoided unnecessary bitterness for a long time. Please don't mess with it lightly.

—Jeff Waugh, on “GNOME vs. KDE” stories

If I, as an individual, go to a Web site, I don't want the identity I use there to be shared between that Web site and other Web sites. So, if I go to Amazon and then I go to a government Web site and then later I go to a Web site that sells music or something, I don't want all of those sites to develop a marketing practice of putting together a generalized biography of me, Kim Cameron, the consumer.

—Kim Cameron, chief identity architect and strategist, Microsoft

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