Data and statistics on the latest versions of the Linux kernel
| Linux version |
Number of files¹ |
Lines of source text² |
development period |
Number of commits³ |
Diffstat4 |
| 2.6.20 | 21280 | 8102486 (7400843) |
66 days | 4768 | 5825 files changed, 262475 insertions(+), 136162 deletions(-) |
| 2.6.21 | 21614 | 8246470 (7522286) |
80 days | 5016 | 6568 files changed, 319232 insertions(+), 175247 deletions(-) |
| 2.6.22 | 22411 | 8499363 (7744727) |
74 days | 6526 | 7620 files changed, 519591 insertions(+), 266699 deletions(-) |
| 2.6.23 | 22530 | 8566554 (7818168) |
93 days | 6662 | 7203 files changed, 406268 insertions(+), 339071 deletions(-) |
| 2.6.24 | 23062 | 8859629 (8082358) |
107 days | 9836 | 10209 files changed, 776107 insertions(+), 483031 deletions(-) |
| 2.6.25 | 23810 | 9232484 (8396250) |
83 days | 12243 | 9738 files changed, 777371 insertions(+), 404514 deletions(-) |
| 2.6.26 | 24270 | 9411724 (8535933) |
88 days | 9941 | 8676 files changed, 595393 insertions(+), 416143 deletions(-) |
| ¹[VERBATIM1] ²[VERBATIM2] ³[VERBATIM3] 4[VERBATIM4] |
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Summa summarum 2.6.26
| Downloading the Linux kernel The new Linux versions are available from servers located in the USA and Europe under kernel.org; numerous mirror servers, also host their content. Linux users, however, should not attempt to install the Linux drivers and kernels themselves, but rather they should wait until the Linux distributors have a chance to do their work. |
Once again, 2.6.26 has a whole range of improvements. However, there are somewhat fewer changes in this version that will directly benefit Linux users who do not deal with the kernel itself than there have been in the previous four or five versions. For this circle of users, the new kernel version will benefit notebook users the most, since improvements to WiFi and power management techniques are tangible benefits.
Development speed has not slowed much since the record setting releases, 2.6.24 and 2.6.25, since the number of commits and the number of changed lines of source code in 2.6.26 is also significantly greater than it was in typical versions of the kernel a year or two ago. This is due in no small part to the Git source code administration system, initiated by Linus Torvalds himself and used by Torvalds and many other kernel hackers. The father of Linux has been using this system now for as long as the Bitkeeper proprietary software he used previously.
Kernel trends: What's new in 2.6.27
Immediately following the 2.6.26 release, the first, approximately two week long phase of the Linux kernel development cycle usually begins, in which Torvalds integrates more comprehensive changes into the next version of the main development branch that he maintains. Now that the linux-next developer branch, started in February, has spent the past three months getting a head start, merging practically all of the important subsystems, the patches of various developers ought to be better coordinated this time than in previous versions.
A closer look at linux-next and the subsystem developer branches integrated there provides a rather complete picture of what to expect in 2.6.27. The biggest change to be found there at the writing of this article was the elimination of the arch/ppc/ directory. The files in that directory are obsolete, since the code in arch/powerpc/ now handles the currently supported Power and PowerPC architectures. Significant adjustments are also in store in the source code for KVM, which means that the 2.6.27 patch is likely to be rather comprehensive.
David Woodhouse has prepared a huge number of patches for 2.6.27 which allow drivers in the kernel to use firmware loaders rather than embedding firmware directly into the kernel or the corresponding kernel module. This will allow Linux distributors in the long run to distribute firmware files independently of the kernel and to distribute newer versions of the firmware on request. Woodhouse even wanted to distribute firmware independently of the kernel sources â some of the kernel maintainers, however, were not especially enthusiastic about this plan.
| The Linux kernel development cycle The open development process (and a deep gaze into the tea leaves) makes it possible for Heise Online, like the Linux Weather Forecast , a "radar screen" maintained by the Linux Foundation, to make an educated guess about what new features are in store in the next kernel version. |
There is also a new file system,UBIFS, in linux-next. It is based on UBI and not intended for hard drives, but rather tailored to the special characteristics of simple flash memory media that do not employ hardware wear levelling. Also, a patch for 2.6.27 will complete the currently partial support for wireless USB.
Following the discussions and performance problems with the Big Kernel Lock (BKL) mentioned above, numerous developers have called for its elimination (see also 1, 2). Accomplishing that will take some time -- there is an array of patches in linux-next, which will in all likelihood be integrated into 2.6.27, that will help to take the first big steps in that direction.
The chances are not bad for the integration of an overhauled version of the Rfkill framework, which supports switches and function buttons used for switching WiFi, Bluetooth, and other wireless services on and off in notebooks. But it is more likely that these updates, like the big changes in the virtual memory subsystem, will not be added until version 2.6.28 appears.
Much discussed, but still not on the way in 2.6.27, are changes that allow the kernel to deactivate unused SATA ports on AHCI controllers to save power. According to Intel developers, this should save 0.75Â W on "most" notebooks, but kernel developers are not exactly of the same mind on the best approach to this issue. It is also not yet clear whether the developers will accept the patch supporting the Intel management engine interface (HECI/Host Embedded Controller Interface).
Various kernel and X developers are working on patches, initially discussed on the LKML during 2.6.22 development, that give the Linux kernel central tasks related to graphics card initialisation and monitor controlling the (kernel-based modesetting). It is still unclear after so many delays whether these extensions will be integrated into 2.6.27, but right now it looks a bit like the patches may not make the final cut.
As usual, Heise Online UK will report in the coming weeks on the most important new features integrated into the Linux main development line and other developments in the Linux kernel. Among these are the new versions of the (2.6.x.y) stable kernel series, which usually correct some error or other that kernel hackers and testers failed to catch in developing 2.6.26.
Linux version 2.6.27 should be released roughly in the middle or end of of September.
Attachment: More changes to drivers and infrastructure
![Kernel Log: Coming in 3.10 (Part 3) [--] Infrastructure](/imgs/43/1/0/4/2/6/7/2/comingin310_4_kicker-4977194bfb0de0d7.png)
![Kernel Log: Coming in 3.10 (Part 3) [--] Infrastructure](/imgs/43/1/0/4/2/3/2/3/comingin310_3_kicker-151cd7b9e9660f05.png)
