Tech Industry

Linux kernel release falls behind schedule

The next version of the heart of Linux likely will appear as late as September, not in July as originally expected, the leader of the Linux movement says.

The next version of the heart of Linux likely will appear later than expected, the leader of the Linux movement said today.

The new Linux kernel, version 2.4, likely will be released in August or September, said Linus Torvalds, founder and leader of the Linux movement. Torvalds initially had hoped 2.4 would be released in 1999, but in February he amended his prediction to July, 18 months after the current 2.2 kernel was released.

However, Alan Cox, the second in command of Linux, still hopes for a July release. Although he said in an interview today that he was unhappy with the delay, he added that "I'd rather be frustrated by the delay than have users frustrated by unreliable code."

The 2.4 kernel includes major improvements, most notably enhanced ability to take advantage of servers with multiple processors. This is a key area as Linux expands for use on ever more powerful servers.

There are few hard-and-fast deadlines in the loosely organized programming community that collectively develops Linux, the now established alternative to Windows and Unix. But with many companies relying on Linux and more serious competition, Linux developers now carry a much heavier responsibility.

Linux is the key product on which companies such as Red Hat, TurboLinux, Caldera Systems and VA Linux Systems depend. IBM has aggressively embraced it, and all other major server makers offer Linux models as well. At the same time, Microsoft's Windows 2000 has finally emerged and is recognized to be much more stable than its predecessor, Windows NT, while Sun Microsystems has made its Solaris operating system nearly free.

Torvalds takes responsibility for much of the delay, pinning the blame on his preference to fix errors sooner rather than later. "The main problem is 'just one more' kind of thing, whether it be a new feature or just an 'obvious cleanup,'" Torvalds told CNET in an interview today.

To watchers of the kernel mailing lists, the slipping schedule is no surprise. Torvalds released the 2.3.0 kernel, the first version of the odd-numbered kernels meant only for development, not use in production. The kernels have been creeping up to 2.4, with the most recent release being 2.3.99.

In February, Torvalds exhorted programmers to spend time on the comparatively mundane bug-fixing instead of the more exciting work of adding new features. He predicted the arrival of programming help from businesses would help with the bug-fixing.

Torvalds and Cox both are excited by the improvements to Linux's ability to take advantage of symmetrical multiprocessing (SMP), computers with more than one CPU. The core improvement to 2.4 is that a given CPU won't hog access for as long to a shared resource--a communication channel to a hard disk, for example.

The results are "quite stunning in many areas," Torvalds said. "It's actually quite visible. You can tell the difference under load just by the feel of the system."

With the 2.2 kernel, released in January 1999, Linux became better able to work on two-processor and four-processor machines. Many Linux developers hope the 2.4 kernel will let Linux "scale" to computers with eight or more processors. CNET's Linux Center

"We don't have any third party benchmarks on this, but the current benching seems to indicate we have most of the SMP scaling problems in the file and network area comprehensively squashed," Cox said. "I don't know if we will scale to the 64 processors on a top-end (Sun E10000 server) yet, but we are getting better."

Improving Linux for multiprocessor machines isn't as easy as some of the earlier improvements. Among other things, amateur programmers aren't as likely to buy two-processor machines, much less those with eight.