LJ Archive


diff -u: What's New in Kernel Development

Zack Brown

Issue #159, July 2007

The DevFS entry in the MAINTAINERS file is no longer marked obsolete. It has now been completely removed from that file, and the last vestige of the old DevFS code is gone. An interesting facet of this history is that udev, which has replaced DevFS, is now subject to its own brand of controversy, albeit completely different from what surrounded DevFS. Some vendors are finding that they can't make good use of udev without using MODULE_LICENSE() to release their code under the GPL. With such fundamental parts of the kernel insisting on the GPL for third-party modules, it soon may be difficult for any binary-only kernel drivers to exist at all.

JFFS is gone. The code has been removed from the kernel, and the maintainer entry has been removed from the MAINTAINERS file. This is all well and good, because JFFS2 has superseded JFFS for a long time, and any lingering JFFS users out there really should switch over to JFFS2.

The parallel port code, once such a key part of many users' systems, is now unmaintained. David Brownell had been unsuccessful at contacting any of the four folks listed in the MAINTAINERS file under that entry, and finally, he posted a patch marking the code unmaintained. Jean Delvare and Randy Dunlap both support the change, and Andrew Morton seems likely to accept it. If you're interested in seeing the parallel port code stay in the kernel, now's your chance to speak up and take it over.

As Vassili Karpov has discovered to his dismay, CPU stats are not accurately reported in /proc/stat on the PC architecture. On that architecture, CPU usage is examined only during the timer interrupt, so regular programs can seem to use much more or much less of the CPU, just because they happen to be either very active or idle at those particular intervals. This also explains why users might see a difference in CPU usage when switching their kernel from running at 100Hz to 1,000Hz. In fact, the usage is unchanged, while only the accounting is different. Programs like top, which get their CPU stats from /proc/stat, will suffer from this kind of discrepancy. Vassili and his friends wasted quite a bit of time trying to optimize some code they were working on, until they discovered that they were optimizing toward an inaccurate and ever-changing goal.

The kbuild system is likely to get some new maturity indicators to go along with “Experimental”. It's been suggested that “Deprecated” and “Obsolete” would be some nice additions. The only problem is that folks currently seem unable to agree on the meaning of those terms. To some folks, “Obsolete” means a replacement is available; although to others, it means the code is completely dead and unsupported. It's very likely that these disagreements will resolve themselves in the relatively near term; everyone seems to agree that kbuild will be improved by having some kind of additional maturity indicators.

The kernel.org folks have forked gitweb, because the gitweb maintainers were not responsive enough to their bug reports. However, it turns out that the kernel.org folks don't have the time to maintain gitweb themselves, so they are missing out on important improvements being made to the upstream tree. At the same time, the gitweb maintainers did seem to be gathering up bug fixes eventually. It seems as though this particular code fork may be short-lived.

Deepak Saxena has modified the kernel to make sure it can build under a Cygwin environment. Some people may wonder why the kernel developers would bother supporting a kernel development environment under Windows, but as Deepak puts it, this environment “is unfortunately used by more people than one would think in the embedded world”. His patch, it turns out, is a bit hacky, and H. Peter Anvin has asked him to include various appropriate comments to make sure anyone touching the code doesn't break Cygwin support.

LJ Index, July 2007

Doc Searls

Issue #159, July 2007

1. Number of keystrokes required to bring up a document at the FBI: 13

2. Cost in millions of dollars of the FBI's scrapped Virtual Case File (VCF) system: 170

3. Number of IT managers on the VCF system in 40 months: 15

4. Estimated cost in millions of dollars of VCF's replacement, Sentinel: 425

5. Expected years until Sentinel is due to be finished: 2

6. Daily petabytes of Internet Protocol traffic carried by Level 3: 3.7

7. Percentage of Hollywood films that show tobacco use: 75

8. Number of actresses in the Linux-hosted Female Celebrity Smoking List: 6,409

9. Percentage of spam sites among .info domains: 68

10. Percentage of spam sites among .biz domains: 53

11. Percentage of Blogspot.com blogs that are fake spam blogs or splogs: 77

12. Percentage of hometown.aol.com blogs that are splogs: 91

13. Percentage of home.aol.com blogs that are splogs: 95

14. Peak number of splogs created every day, in thousands: 11

15. Thousands of splogs removed from Technorati in early December 2006: 341

16. Position of Japanese among the top blogging languages: 1

17. Position of English among the top blogging languages: 2

18. Position of Chinese among the top blogging languages: 3

19. Position of Italian among the top blogging languages: 4

20. Percentage of blog posts that used tags in February 2007: 35


2–5: Fast Company

6: Level 3

7: TIME Magazine

8: Smoking From All Sides (smokingsides.com)

9–13: Infoniac.com

14–20: Technorati

lighttpd Is in the House

Doc Searls

Issue #159, July 2007

In April 2007, Netcraft's monthly survey (news.netcraft.com/archives/2007/04/02/april_2007_web_server_survey.html) showed a new entry in its top five Web servers: lighttpd (www.lighttpd.net). At that point, Lighty (or lighttpd) clocked in at 1.4 million sites, not including the reported Apache sites hosted by OpenSourceParking (opensourceparking.com) that Netcraft claims may actually have been running lighttpd. Says Netcraft, “The opensourceparking.com headers say Apache, but have the Date & Server headers last, a pattern which is identical to the lighttpd response and entirely unlike a typical Apache response. The etag is also not in Apache format, and matches the lighttpd format” (news.netcraft.com/archives/2007/04/04/open_source_parking_spoofing_headers_to_benefit_apache.html).

Jan Kneschke began work on lighttpd in 2003, when he wanted to develop a fast and lightweight alternative to Apache. Since then, a community has grown around lighttpd, which has its own home (with a blog, a wiki and a forum) at lighttpd.net. The description there goes:

lighttpd is a secure, fast, compliant and very flexible Webserver that has been optimized for high-performance environments. It has a very low memory footprint compared to other Webservers and takes care of CPU load. Its advanced feature set (FastCGI, CGI, Auth, Output-Compression, URL-Rewriting and many more) makes lighttpd the perfect Webserver-software for every server that suffers load problems.

Meanwhile, Apache (in April 2007) stood at a 58.63% share of the Netcraft surveyed sites, running roughly flat month to month after it dropped about the same 5% that Microsoft servers gained in April of last year. Don't be surprised to see lighttpd and Apache combine to increase open-source server market shares, while also increasing choice. Watch Netcraft (news.netcraft.com) for more developments.

Palming Linux

Doc Searls

Issue #159, July 2007

The term PDA (personal digital assistant) was coined in 1992 by Apple CEO John Sculley to name a category for a new class of handheld devices, inaugurated by Apple's Newton. Sculley moved on and Newton flopped, but the category stayed. Starting with the Palm Pilot in 1996, the Palm brand has been synonymous with the PDA category, even as the company called Palm has gone through multiple incarnations and the most familiar PDAs are also cell phones.

From the beginning, Palm has had its own operating system, called PalmOS (Garnet). In recent years, the company has added Windows Mobile for use in some of its cell-phone PDAs. (For example, the Palm Treo 700 comes in Palm and Windows versions.)

Then, at its Analyst and Investor Day in April 2007, Palm announced plans to moosh its PalmOS development together with development atop the Linux kernel, along with plans to come out with Linux-based Palm products before the end of this year. We don't have more specifics at press time, but we do have a copy of a visual used by Palm at the announcement (Figure 1).

Figure 1. Palm Planning Linux-Based Products

Looks like another example of World Domination at work. Resistance is futile.

They Said It

San Diego is skilled at the use of computers to include setting up e-mail services and using the programming language Linux. He is also skilled at sailing, particularly small sailboats. San Diego has traveled internationally.

—From an FBI Wanted notice for Daniel Andreas San Diego. Later “operating system” was substituted for “programming language”. Original source: www.digg.com/linux_unix/FBI_Linux_is_a_programming_language; current source: www.fbi.gov/wanted/fugitives/dt/sandiego_da.htm.

Linux is not about free software, it is about community....It's not like Novell; it isn't going to run out of money—it started off bankrupt, in a way.

All the computer people use Macs or Linux now. Windows is for grandmas, like Macs used to be in the 90s. So not only does the desktop no longer matter, no one who cares about computers uses Microsoft's anyway.

Scarcity models are by definition not scale-free; a hit culture prevails. Open source, given the lower barriers to entry, allows someone to build left-handed credit derivatives juicer because he felt like it. There's a long-tail effect. You are more likely to find esoteric tools in an open-source world than in a closed-source one. Open-source people don't go around asking, “Is there a market for this?” They solve problems and see if others have similar problems to solve.

I can't help but wonder what would have happened if John D. Rockefeller had patented a system for transferring gasoline from a fixed source to a mobile device using a hose that fit into an cylindrical pipe.

GOOGLE'S WORST NIGHTMARE: Wikipedia's JIMMY WALES Has His Sights Set on the Search Business—Cover headline of the April 2007 edition of Fast Company.

In the current issue of Fast Company, right below my face it says, “Google's Worst Nightmare”. And I think, God, I should really get to work on that search engine.

LJ Archive