19 December 2008, 12:45

Kernel Log: What's coming in 2.6.28 - Part 9: Fastboot and other remainders

Kernel Log logo The previous eight parts of the kernel log's "What's coming in 2.6.28" series discussed some of the most important changes to the Linux kernel incorporated with 2.6.28. Quite a few of the commits for the main development branch, however, don't really belong to any of the topics discussed in the series so far and as a result, haven't yet been mentioned. In other cases, the kernel developers have made minor, but significant changes to some kernel areas, after we had covered them.

For example, we haven't mentioned some of the changes introduced by Intel developer Arjan van de Ven to speed up hardware initialisation and booting (see 1, 2, 3, 4). Van de Ven used these and several other changes rejected by Linus Torvalds on a netbook that only required five seconds for starting Linux in a demonstration at the Linux Plumbers Conference. With the majority of systems, however, Linux 2.6.28 will start up only marginally faster, despite the fastboot patches, as the popular mainstream distributions waste most of their time initialising userspace services and loading the log-in manager and desktop environment. Those who want to analyse the required kernel initialisation time for optimisation regardless, now have access to a new tracing infrastructure specifically designed for this purpose.

Apart from the heise Kernel Log, several other kernel developers and numerous online media have taken a closer look at the changes incorporated with Linux 2.6.28. The overview at kernelnewbies.org, for example, offers its usual detailed review, while LWN.net founder and executive editor Jonathan Corbet, keeps his summary brief in the Linux Foundation's Linux Weather Forecast and in a relevant blog entry. However, Corbet discusses the changes in more detail in three articles on LWN.net, which also include mention of the changes to the kernel's programming interfaces that are important for developers (1, 2, 3). The developers of the WLAN subsystem have summarised the most important developments in the WLAN area in their wiki. The wiki of the FireWire developers divulges that some, seemingly inconspicuous, commits in the FireWire subsystem are designed to make this subsystem more resilient against connection terminations.

Linux 2.6.28 will probably be out in the next few days, as Linus Torvalds made the kernel's ninth release candidate available a few hours ago, announcing that 2.6.28 will be a "Christmas release". ("And btw, I do think that I'll make 2.6.28 be a Christmas release (or Hanukkah, Kwanzaa, Solstice, Insert-Favorite-Holiday, whatever). Because quite frankly, this kind of boredom won't help anything and I'll go stir crazy if I have to do this for another two weeks.") Torvalds wants to extend the next kernel version's merge window, which is usually open for the two weeks directly after a new release, to give the kernel hackers that are taking time off during the holidays, enough time to prepare and submit their changes for the next kernel version.

Numerous other important, but not quite as relevant changes in 2.6.28 we haven't discussed so far:

ACPI:

Networks:

File Systems:

Storage:

Graphics:

Documentation:

Miscellaneous infrastructure and architecture support:

Various drivers:

Further background and information about developments in the Linux kernel and its environment can also be found in previous issues of the kernel log at heise open: