Alan Cox hails 64-bit Linux

The advent of affordable 64-bit computing could be the best thing to happen to Linux in a long time, opening up a new market potentially as important as the original PC market, according to Linux "kernel hacker" Alan Cox. He also criticised new guidelines suggested by the Internet Engineering Task Force (IETF) covering the reporting of software security holes.

Click here for part one of ZDNet UK's exclusive interview with Alan Cox

New processors emerging from AMD and Intel -- whose main focus has until now been desktop chips -- will allow many companies currently locked into expensive computer systems to switch to mainstream chips and open software like Linux, Cox said. The new Itanium line from Intel and the upcoming Hammer range from AMD offer similar performance to the RISC processors made by the likes of IBM and Sun Microsystems, but aim to achieve desktop-level prices.

"Large numbers of people will be able to dump a lot of expensive hardware," said Cox in an interview with ZDNet UK. "It will effectively extend the PC into a whole new market area. It could be as big as the 386." The 386 was an Intel processor introduced in the late 1980s, known to Linux developers as the first consumer processor powerful enough to run industrial-strength software like the Unix operating system.

The 386 was instrumental to the early growth of Linux, a Unix-like operating system that many say could replace Windows as the dominant software on PCs. Once reasonably powerful hardware was available for a low cost, a large number of programmers began installing and improving Linux -- Cox, then a student at the University of South Wales, among them. The result, more than ten years later, is the software that runs a good number of the servers on the Web and many of the protocols that make the Internet work.

AMD's Hammer is particularly promising, Cox said, because it will run on both consumer and server platforms right away. Unlike Itanium, Hammer is optimised to run software based on the current x86 instruction set as well as 64-bit software. Itanium places the emphasis on 64-bit code, leaving the consumer market to the Pentium 4 for the near term.

Cox, an employee of Linux vendor Red Hat, is now one of the chief developers on the Linux core -- or kernel -- and is largely responsible for coordinating and integrating the contributions of hundreds of developers around the world. Linus Torvalds, who initiated the Linux project as a student in Finland, still has the final say on modifications to the kernel.

A controversy arose recently over whether the job of applying "patches" was getting to be too big for one person, but Cox says he feels the solution that emerged, involving automating the kernel changes, is ultimately satisfactory. "The free software community has a way of self-correcting when problems arise," he said.

Linux is based on the "free", or open-source, development model which requires developers to make the original programming code of their software improvements freely available to other developers.

Communal debugging is central to open-source development, and Cox bridles at recent attempts to change the way bugs are reported to software vendors. A recent draft protocol from the Internet Engineering Task Force (IETF), for example, has been criticised for stigmatising those who report security holes before the software vendor has had a chance to create a patch, and Cox tends to agree with some of the criticisms.

"It's too prone to let things run and run and run," he said. "If the vendor hasn't fixed the bug in 28 days, then tough -- after that you're not reporting bugs, you're covering up for a company's incompetence, and there's a very big difference."

The immediate challenges for Linux developers include extending its capabilities for both power users and grandmothers, Cox believes. On the high-end, scalability is becoming an increasingly important issue, while it's also crucial to make Linux accessible through simple interfaces, he said.

The emerging use of hyperthreading within Intel's Pentium 4 processor means that Linux must scale even within the chip. Hyperthreading is designed to improve performance by allowing the chip to behave like a two-processor system. It is present in all Pentium 4s but is only made use of so far in the new server P4, called Xeon.

Progress was made in this direction last year, said Cox. "The 2.4 kernel is coming of age," he said. "It is getting more scalable, especially with four- and eight-way machines. That's the direction the market is going."

On the other hand, simplicity is more important than power if Linux is to penetrate certain markets, like small businesses and the home, Cox argues. He applauded the advances last year made by organisations focused on user interfaces, such as GNOME and KDE.

The home market is the toughest market to crack in many ways, he said, because of the particular needs of consumers. Ultimately, though, the all-purpose PC as championed by Microsoft may prove to be less attractive to home users than a simpler, less expensive machine specialised for applications like Web use and productivity tools. Linux is ideal for such machines because of its low cost, reliability and flexibility.

"You could question whether the consumer PC market will survive in its current form," he said.

The shift to specialised, Web-centric devices is made easier by the fact that the new applications users want no longer require a monolithic, standard operating system, but simply a standards-compliant Web browser, Cox said. Microsoft argues that users will always want a uniform operating system so that everyone can run the same applications; it also says its operating system monopoly makes things easier for developers by providing them with a huge, homogenous market.

Cox's views, not surprisingly, tend in the opposite direction. "There shouldn't be one worldwide operating system," he said. "Peoples' needs are all very different."

One Linux innovation last year that was less than a complete success was last year's "Kernel Summit", where many of Linux's main contributors, including Torvalds and Cox, met face to face to coordinate their plans. The official part of the programme wasn't very productive, although things picked up after hours.

"The amount of work that got done over beer at 3 am cannot possibly be calculated," he added.

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