Introduction to the Linux Kernel 2.6 For The Fraser Valley Linux Users Group By Alan Bailward

Overview What is a “kernel” What does this release mean Nifty new things Back-end changes Upgrading Question Time Resources

What is a Kernel ● Core of the OS ● Controls all input and output ● In development since 1991 ● Works in conjunction with your shell, tools and applications

What 2.6 Means ● The 2.6 designation means that this is a stable kernel ● Almost ● Currently (12/7/2003) at test11 ● Linus is anticipating the full release by the end of the year ● Already very stable and many are using it ● More “industry strength” features ● Improved user experience

Nifty New Things ● New menu systems (gtk and qt)

Nifty New Things Cont... ● New build system – No more compile messages! (unless you use V=1)

Back-end Changes ● Hardware Support – better embedded support – better NUMA (non-uniform memory access... think SMP++) support – Hyperthreading ● Scalability – PAE (physical address extension to allow x86 to access up to 64G of ram) – higher limits on PIDs and device major and minor numbers

Back-end Changes 2 ● Interactivity – preemptible ● kernel operations can be interrupted ● improves responsiveness ● “feels faster” ● supposedly better than the 2.4 preempt patches – threading ● start and stop 100,000 threads in 2 seconds (vs 14:58 before)

Back-end Changes 3 ● Modules renamed to.ko ● Stability improvements to the module subsystem ● ISA, EISA, PCI systems are modules ● Hotplug improvements ● New filesystem sysfs – /sys – joins /proc, /dev (devfs) and devpts – has all known attributes of the device (irq, dma, power status, etc)

Back-end Changes 4 ● Better PnP ● USB 2.0 (“high speed”) ● Wireless support merged into single subsystem – amateur radio AX.25 – wireless ● Infrared updates ● Bluetooth updates ● IDE updates and scalability improvements ● No more ide-scsi for CD writing! ● New Serial ATA drivers ● SCSI updates

Back-end Changes 5 ● Ext2/3 extended attributes – meta-data and finer grained permissions – catching up to windows in this respect! ● XFS added ● NFS improvements, r/w better but still experimental ● Quota support more scalable

Back-end Changes 6 ● Human Interface layer – create a completely headless system – complete modularity for video, keyboard, mouse, and all things human (ph34r the machines!) ● Touch screens ● Strange mice ● Braille devices ● Magic sysrq key now not only from a console ● ALSA (advanced linux sound architecture) merged

Back-end Changes 7 (last one!) ● Networking updates – many small changes here and there – IPSEC support ● allows for transparent cryptography through ipv4 and ipv6 – VLAN (for routers) support no longer experimental ● Network filesystem updates – NFSv4 support – CIFS (streamlined SMB) ● Many security updates – alternate security modules begun ● User mode Linux ● APM/ACPI improvements

The “Gotchas” ● Not all non-open source packages are updated yet ● May need patches for – vmware – nvidia ● My own personal experience: – mouse speed changed – mouse buttons stopped working – vga=791 frame-buffer no longer worked ● have heard of problems with CD burning ● some apps aren't updated yet ● Gentoo changes with devfs and ptyfs

Upgrading ● module-init-tools ● mkdir /sys ● ensure keyboard and video are loaded in ● pty filesystem

Questions?

Resources ● ● ● ● ● ● ●