Torvalds originally wanted to release the 2.4.0 version of the Linux "kernel" in 1999, but cramming in a host of new features took longer than expected. The 2.4 kernel improves Linux's ability to run on high-end servers with several CPUs and adds support for desktop features such as universal serial bus.
Torvalds, who began the Linux project in 1991 and still decides when to post new versions of the kernel, put up the 10th test version of the 2.4 kernel Tuesday. In a posting to the Linux kernel mailing list, he named it "test10-final."
"This has no known bugs that I consider show-stoppers, for what it's worth," Torvalds said. "And when I don't know of a bug, it doesn't exist."
Torvalds said he was optimistic the final 2.4.0 would arrive soon. "In traditional kernel-naming tradition, this kernel hereby gets anointed as one of the 'greased weasel' kernel series, one of the final steps in a stable release," he said.
In a later posting, Torvalds acknowledged a flaw with a new feature called Raw I/O that improves the speed of a computer's communications with storage systems. The flaw "will have to be fixed before anybody starts doing Raw I/O in a major way," he said, "but it's not on my list of 'I cannot release a 2.4.0 before this is done.'"
But just including the word "final" in the latest test version of the kernel doesn't guarantee immediate results. In May, Torvalds released the first of the 2.4.0-test series of kernels, hoping that using the "2.4" nomenclature would focus programmers' attention on producing software usable by companies instead of just an interesting prototype.
Red Hat, the top seller of Linux, predicted a production-ready version of Linux 2.4 would be done late this year or in early 2001.
The 2.4 kernel's improvements for multiprocessor servers have led the Linux-Sparc programming team and Linuxcare to declare that the new kernel can efficiently use all the processors in the 24-CPU Sun E10000 server. And programmer Clay McClure was able to get Linux running on a 48-processor E10000, he said.
However, Sun Microsystems, which prefers its own Solaris operating system to its cousin Linux, said Linux is several years behind other versions of Unix.
Sun moved to the System V version of Unix when it introduced Solaris, dropping the Berkeley distribution software that was at the heart of Solaris' predecessor, SunOS. In the process, Sun made major changes so Solaris could work on multiprocessor systems, said Andy Ingram, head of Solaris marketing.
"SunOS looks a lot like Linux today. It looks the same, it reacts the same, it has the same scaling challenges," Ingram said. "We moved away from that to a new and modern kernel. It created all sorts of pain when we did it."