The Linux Letter for December 27, 1999

After a three week hiatus, it's time to get back to work! The last time we met, I told you all about the projects that were on the front burner here at the computer ranch. Almost everything is well underway. So now we can look ahead to what's coming for Linux next year!

Linux 2.4 is just around the corner, coming very soon into 2000. If you remember the ballyhooed introduction of Linux 2.2, you know that there were some huge improvements over the old 2.0 kernel. Don't expect the same sort of advances from 2.2 to 2.4. According to Joe Pranevich's Wonderful World of Linux 2.4, new kernels will come at a greater clip than before and that means fewer significant improvements, but more rapid incremental changes.

Most of the changes won't be visible to the average user. High end systems that run many processes will benefit by an increase in the number of simultaneous threads...from 1024 to a potential of 16,000. Intel systems will be able to support up to 4GB of physical memory.

Linux 2.2 supported the Intel memory type range registers (MTRR) and the support will be improved in 2.4. AMD K7 processors have two of them and Cyrix processors implement a variation called MCR. Linux 2.4 will support them. If your system has multiple processors, you know that Linux 2.2 improved the support for the advanced programmable interrupt controller (IO-APIC) that spreads interrupts across processors. Kernel 2.4 takes this a step further and supports high-end system that have multiple IO-APICs, which means that Linux will scale even better on systems with many processors.

If you're like me, you probably have a system with the Universal Serial Bus. USB support will be available in Linux 2.4. While individual device support is slowly growing, many hardworking programmers are readying drivers for popular devices right now. PnP for ISA devices will be included in the kernel, so no external utilities or drivers will be necessary. Just don't count on installing that Winmodem anytime soon.

IDE device support will also improve. The total number of IDE controllers allowed will be 10 in Linux 2.4, up from a maximum of 4 in 2.2. That allows for a potential of 20 IDE devices in a single system. UDMA support will be a new feature.

The same array of file systems in Linux 2.2 will be present in 2.4. OS/2 users will be able to write as well as read from their partitions. Also, those of us who mount Windows drives using SMB won't have to enable the workaround for the broken Windows 9x systems. The kernel will be able to detect the system and implement the fixes on the fly. An even more anticipated improvement is the upgrade of the network file system (NFS) to be NFS3 compatible. 

USB keyboards and mice will work! They behave just like their standard serial or PS/2 counterparts that we're used to.

Parallel port performance has been improved to allow for Plug and Play devices and DMA support. Printers and other parallel devices that support them will show a noticeable speed increase.

The networking layer has been completely rewritten to scale much better than before. It has been optimized to allow it to work with odd networking stacks (including Windows). Linux 2.4 will be the first operating system to be fully compatible with Ipv4.

PPP has been rewritten to modularize the code which combines the PPP layers from ISDN with those of serial devices.

If you can't wait for Linux 2.4 to be released, you can sample much of it by downloading and installing the latest development kernel (2.3.33 as of this writing). The usual warnings about running developmental beta software applies.

Wonderful World of Linux 2.4: http://linuxtoday.com/stories/10698.html

Linux Kernels: http://www.kernel.org

 

So you're done using your CD-ROM drive and you've tried to unmount it, but mount tells you that it's busy. Don't give up...find out what process is using it! Just issue this command:

fuser -l /dev/cdrom

The command will list the processes using the CD-ROM's file system. Or, if you're feeling adventurous and don't care what processes are using the CD-ROM, try:

fuser -k /dev/cdrom

This will kill all of the processes that are using the CD-ROM.

Happy computing!

Drew Dunn