GIF>I8DD@E> Kernel News Q8:BËJB

DX`ekX`e\ij_`gLg[Xk\j Alessandro Rubini has abandoned Kristoffer Ericson created a MAIN- scheduler/ userspace chain of events maintainership of the “Mouse and misc TAINERS entry for the Epson within the running kernel. In fact, the devices (general)” code, which actually S1D13XXXFB driver and listed himself as whole package has been so useful that it hasn’t existed for a long time. The the official maintainer, “… since I have 2 is now included in the official kernel generic mouse interface has been part platforms currently using it,” he said. tree, which is something Thomas had of the input subsystem maintained by This controller is used for various LCD never envisioned when he first created Dmitry Torokhov, and miscellaneous screens, typically embedded as display Cyclictest. drivers are handled individually. Both panels in other devices such as printers, Kentaro Takeda has posted a patch the maintainer and the project itself car dashboards, and whatnot. listing himself and Tetsuo Handa as co- were out of date in the MAINTAINERS Theodore (Ted) Y. Ts’o has updated maintainers of the Tomoyo security file, and Jiri Kosina posted a patch to re- the MAINTAINERS file, listing himself as module. This GPL’d project was devel- move it. the ext4 filesystem maintainer instead of oped by the NTT Data Corporation and Rodolfo Giometti has added an entry Andrew Morton and Stephen Tweedie, implements MAC (mandatory access to the MAINTAINERS file, listing himself although this doesn’t represent an actual control) security policies on files, net- as the official PPS (pulse per second) shift in maintainership. According to works, and other system resources. maintainer. PPS provides an API for pre- Ted, the entry was originally just copied Peter Oruba removed himself as main- cise time measurements that can be used from the ext3 entry and never had been tainer of AMD Microcode Update Sup- to synchronize clocks on disparate com- accurate. Ted’s patch just corrects the in- port and listed Andreas Herrmann in- puters. Although several implementa- accuracy. stead. This code handles the insertion tions are available for PPS in Linux, this An interesting detail is that, although of new updates into the microcode that one is Rodolfo’s. Its benefits are that it Andreas Dilger is not included in his controls how the AMD CPU functions. makes it easy to add and manage new patch as a co-maintainer, the list of ap- In July 2008, Peter originally introduced sources of timing information into a propriate email addresses for patch sub- this code into the kernel and has main- pool, with a consistent interface for each missions, bug reports, and so forth in- tained it since then. source. cludes Andreas’ email address alongside Mike Frysinger posted a patch to the Ted’s. Andreas’ email was also listed MAINTAINERS file listing himself and The Linux kernel alongside Andrew’s and Stephen’s in the Subrata Modak as co-maintainers of LTP mailing list com- original mistaken entry. Typically, this (Linux Test Project). This project, spon- prises the core of would mean that he puts a lot of work sored by SGI and IBM, provides a suite Linux development into the project and can act as a lieuten- of about 3,000 tests addressing reliabil- activities. Traffic vol- ant to Ted, in the same way that Linus ity, robustness, and stability of the Linux umes are immense, Torvalds has trusted lieutenants who operating system. often reaching ten have an easier time getting code into his Phillip Lougher has added an entry to thousand messages tree than other folks. the MAINTAINERS file, listing himself as in a given week, and Len Brown posted a patch removing the official SquashFS maintainer. keeping up to date Kristen Carlson Accardi as the main- SquashFS is a read-only compressed file- with the entire scope of development is tainer of the Docking Station driver and system, intended for embedded systems a virtually impossible task for one per- listing Shaohua Li as the replacement. and other small Linux utilizations – or son. One of the few brave souls to take Both Kristen and Shaohua work for really anywhere else. Currently it sup- on this task is Zack Brown. Intel, so we can assume some internal ports gzip compression because that’s Our regular monthly column keeps you shuffling is going on there. Kristen had the only form of compression available abreast of the latest discussions and de- cisions, selected and summarized by been the official maintainer since July natively in the Linux kernel, but patches Zack. Zack has been publishing a weekly 2006, according to another patch Len are available at http://www. online digest, the Kernel Traffic news- posted at that time. squashfs-lzma. org/ for anyone who letter for over five years now. Even Thomas Gleixner has given maintain- wants to try LZMA compression. reading Kernel Traffic alone can be a ership of rt-tests to Clark Williams. The Michal Januszewski added an entry to time consuming task. rt-tests code contains various test pro- the MAINTAINERS file for the uvesafb Linux Magazine now provides you with grams for the kernel’s real-time support. driver, listing himself as the official the quintessence of Linux Kernel activi- Cyclictest, the original test program that maintainer. Uvesafb is a generic frame- ties, straight from the horse’s mouth. spawned rt-tests, is still included in the buffer driver with a variable refresh rate package and tests the interrupt/ wakeup/ that replaces vesafb-tng.

70 ISSUE 98 JANUARY 2009

070-071_kernel.indd 70 13.11.2008 15:46:58 Uhr Kernel News GIF>I8DD@E>

9`^CfZbLinus Torvalds Greg Kroah-Hartman, the main advo- I\[\]`e`e^CfX[8m\iX^\ has pushed to get rid of the BKL and re- cate of changing the current system, sug- Sena Seneviratne and David Levy have place it with simpler locking structures. gested using year numbers, followed by been cooking up some changes to the However, not all situations can be re- the number of each release done in that load average calculation in Linux. solved with a generic lock, and the lock- year, followed by the number of stable Their idea is that instead of just calcul- ing code has been scattered throughout versions of that release. Thus, 2009.3.5 ating a single number representing the the kernel, making any kind of concerted would be the fifth stable release of the entire load average on the system, multi- effort problematic. One attempt has been third version released in 2009. This, he ple statistics should be available. For to “push” all BKL code into its own part said, would prevent the version numbers one, they want to separate disk I/ O load of the source tree to centralized it so it from getting too large (e.g., 2.6.25). from the rest of the load average calcul- can potentially be dealt with all at once. Given the opposition to the change ation so it can be viewed independently. Developers across the spectrum of kernel among big-time developers and the Also, they want to enable per-user load development have been engaging in a plethora of well-meaning suggestions, average calculation, so each user could search and destroy mission against the the system probably won’t change any- see their effect on the system. Arjan van BKL for months now, but a lot of work time soon. However, the original com- de Ven exhorted them to add statistics remains. Frederic’s tool might help de- plaint came from Linus Torvalds, and only and not to change the behavior of velopers focus their attention on the Greg started the discussion as a way to any numbers that the system already areas that would benefit the most. come up with a recommendation for produces.

C`eloDX^Xq`e\

JANUARY 2009 ISSUE 98 71

070-071_kernel.indd 71 13.11.2008 15:47:00 Uhr