It's The Superman Kernel

by Pamela Jones

December 18 2003

With the release of 2.6 kernel [ ], Joseph Pranevich has updated his wonderful article [ ], "The Wonderful World of Linux 2.6", which details all the new features. This is the Superman kernel. It's the kernel that can get very, very small for a PDA or scale to the enterprise heights. As you read over the new features, perhaps you will form the same impression I did: nobody seems intimidated by SCO.

This is truly an enterprise kernel, scaling up, up and away. Internet Week [ ] quotes Linus:

"'With the new kernel, I think we're getting closer to Linux for everyone,' Torvalds said Thursday. 'I think this is the best yet and I had a lot of fun working on it,' he said in a statement."

Ah, dear Linus. Beating the proprietary types is a byproduct. He's having fun.      

This is a kernel business folks will love. Streamlined and improved SMP, improved support for 64-bit computing, hyperthreading, performance improvements for database applications, full support for the XFS filesystem, and new support for NUMA servers, which the article explains means this:

"NUMA (or "Non-Uniform Memory Access") is a step beyond SMP in the multi-processing world and is a major leap forward for efficiency on systems that have many processors. Current multiprocessing systems were designed with many of the same limitations as their uniprocessor counterparts, especially as only a single pool of memory is expected to serve all processors. On a many-processor system, there is a major performance bottleneck due to the extremely high contention rate between the multiple cpus onto the single memory bus. NUMA servers get around that difficulty by introducing the concept that, for a specific processor, some memory is closer than others."

That's not all this new kernel can do. Look at this paragraph:

"In addition to just supporting new hardware features, internal limits have been also increased when possible. For example, the number of unique users and groups on a Linux system has been bumped from 65,000 to over 4 billion. (16-bit to 32-bit), making Linux more practical on large file and authentication servers. Similarly, The number of PIDs (Process IDs) before wraparound has been bumped up from 32,000 to 1 billion, improving application starting performance on very busy or very long-lived systems. Although the maximum number of open files has not been increased, Linux with the 2.6 kernel will no longer require you to set what the limit is in advance; this number will self-scale. And finally, Linux 2.6 will include improved 64-bit support on block devices that support it, even on 32-bit platforms such as i386. This allows for filesystems up to 16TB on common hardware."

It's also faster, for desktop users too, and has better support for laptops and plugin devices like Firewire and USB devices and enhanced Plug and Play functionality. Touch screens are now supported. Audio is now "completely thread and SMP-safe" and the kernel has built-in support for Digital Video Broadcasting (DVB) hardware. Here is something nice for Novell:

"Although not as commonly seen today, Linux has not completely forgotten about the Novell NetWare users. Linux 2.6 now allows Linux clients to mount up to the maximum of 256 shares on a single NetWare volume using its built in NCP ('NetWare Core Protocol') filesystem driver."

The new kernel also supports the Tieman Voyager braille TTY device for blind users of Linux. As the article puts it, "Like previous releases, the new additions to Linux 2.6 demonstrate the importance of playing well with others and reinforces Linux's position as a 'Swiss Army Knife' operating system." This information about new file systems is interesting too:

"Linux 2.6 also includes improved support for the relatively new domain of distributed network filesystems, systems where files on a single logical volume can be scattered across multiple nodes. In addition to the CODA filesystem introduced in Linux 2.4, Linux now includes some support for two other distributed filesystems: AFS and InterMezzo. AFS, the Andrew filesystem (so named because it was originally developed at CMU), is presently very limited and restricted to read-only operations. (A more feature complete version of AFS is available outside the kernel-proper.) The second newly supported filesystem, InterMezzo (also developed at CMU), is also newly supported under Linux 2.6 and it allows for more advanced features such as disconnect operation (so you work on locally cached files) and is suitable for high-availability applications where you need to guarantee that storage is never unavailable (or faked, when down). It also has applications for keeping data in sync between multiple computers, such as a laptop or PDA and a desktop computer. Many of the projects providing support for these new types of filesystems are initially developed on Linux, putting Linux well ahead of the curve in support for these new features."

At this point, it might be easier to ask: is there anything this kernel can't do? I'm sure it would be a shorter list. There are many more intriguing details in the article. Of all the new features, here's my personal favorite, the security-related changes:

"Most fundamentally, the entirety of kernel-based security (powers of the super user under a UNIX-like operating system) has been modularized out to be one out of a potential number of alternate security modules. (At present however, the only offered security model is the default one and an example how to make your own.) As part of this change, all parts of the kernel have now been updated to use "capabilities" as the basis of fine-grained user access, rather than the old "superuser" system. Nearly all Linux systems will continue to have a "root" account which has complete access, but this allows for a Linux-like system to be created which does not have this underlying assumption. Another security-related change is that binary modules (for example, drivers shipped by a hardware manufacturer) can no longer "overload" system calls with their own and can no longer see and modify the system call table. This significantly restricts the amount of access that non-open source modules can do in the kernel and possibly closes some legal loopholes around the GPL. The final change that is somewhat security-related is that Linux with the new kernel is now able to use hardware random number generators (such as those present in some new processors), rather than relying on a (admittedly quite good) entropy pool based on random hardware fluctuations."

Just think what this means for a business that needs security, like HIPAA entities, for example. DRM restricts everyone and requires even the author to give up privacy. Here you have security without blockages and that kind of annoyance. Hint to Microsoft: you may wish to try to keep up with Linux on security. Otherwise, you will be losing a lot of business, I fear. And as for SCO, for those of us, including me, who wondered if the SCO threats would have any impact, the answer is in: Linux just keeps developing onward and upward, leaping over buildings in a single bound.

Note that the Linux Kernel Archives [ ] page has this advice if you are new to Linux:

"New to Linux?

"If you're new to Linux, you don't want to download the kernel, which is just a component in a working Linux system. Instead, you want what is called a distribution of Linux, which is a complete Linux system. There are numerous distributions available for download on the Internet as well as for purchase from various vendors; some are general-purpose, and some are optimized for specific uses. We currently have mirrors of the Debian [ ] and RedHat [ ] general-purpose distributions available at, as well as a small collection of special-purpose distributions at

Note, however, that most distributions are very large, so unless you have a very fast Internet link you may want to save yourself some hassle and purchase a CD-ROM with a distribution; such CD-ROMs are available from a number of vendors."

Eric Raymond has a Linux Installation How To here [ ]. And last but not least, here [ ] is the list of some folks we can say thank you to. Of course, patches for bugs are already being worked on, as the story continues.

ComputerWorld [,10801,88374,00.html ] quotes what it finds to be a cryptic statement from Linus:

"The beaver is out of detox."

Anybody here find that hard to decode? This is just the internal, silly name of this version of the kernel. Nothing cryptic there.

According to ITWorld [ ] Microsoft is rearranging itself, creating a new central engineering division to work on the core of the Windows operating system:

"To a certain extent, Microsoft's decision to form a division focused on the OS core was driven by its main rival, Linux, said Rob Enderle, principal analyst at Enderle Group, a consulting firm specializing on emerging technologies, in San Jose, California.

"'They have been studying Linux extensively. Part of their study has been on how Linux has been able to maintain a high level of consistency in the kernel while groups around it maintain maximum flexibility,' Enderle said."

02:25 PM EST

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