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In brief

  • Asynchronous Notification (AN), which reports media changes in ATAPI devices, is now disabled by default and can be enabled via the new "atapi_an" driver parameter.
  • The kernel's RAID10 support is no longer classified as experimental. The MD subsystem's code now offers numerous further conversion options: Raid0->Raid5, Raid0->Raid10, Raid5->Raid4, Raid4->Raid0 as well as Raid5->Raid0 and Raid10->Raid0.
  • The new "nconfig" make target in 2.6.35 gives access to a ncurses-based text interface for kernel configuration said to offer a slightly more modern operating concept than "menuconfig".
  • To improve scalability, the kernel developers have further reduced the need for the Big Kernel Lock (BKL) (for instance 1, 2, 3, 4, 5).
  • The xHCI USB driver has supported data transmission since 2.6.35 for the "Bulk Endpoint Streams" implemented in USB 3.0. They are required for some of the patches still being developed to add support for the USB Attached SCSI protocol (UASP) to the kernel's USB storage driver so it can improve traffic rates for USB 3.0 drives.
  • Version 2.6.35 provides the Linux kernel with the i7core_edac driver, which adds support for EDAC (Error Detection And Correction) for Intel‘s Nehalem processors – in other words, processors like the Core i7 and Xeon CPUs from the 35xx and 55xx series.

Which of the drivers were changed

Information about the changes to individual Linux kernel files can be found through the Git web front end at Kernel.org – this, for example, allows users to find out whether there have been changes to the drivers used on their own systems. To do this, however, users need to know where in the Linux kernel's source code tree the driver files are located. For the heavily modular distribution kernels the modinfo program is often helpful when searching:

$ /sbin/modinfo e100 e1000 | grep filename:
filename: /lib/modules/[...]/kernel/drivers/net/e100.ko
filename: /lib/modules/[...]/kernel/drivers/net/e1000/e1000.k

If a compiled module is, for example, located at [...]/kernel/drivers/net/e100.ko, its source code in the Linux source code archive can usually be found in a file with a similar name in the drivers/net/ directory – for example e100.c for the e100 driver for Intel 100 MBit networking hardware. Other modules like the e1000 driver for Intel's PCI Gigabit LAN chips, on the other hand, have a whole directory to themselves. If the approximate location of the driver source code is known, users can navigate to the respective source code files in the tree view of the Git web interface and can then retrieve an overview of the latest file or directory changes via the history link. In the network driver directory, changes to the driver code of e100 (drivers/net/e100.c) and e1000 (drivers/net/e1000/), for example, can be displayed and examined in this way.

Facts and figures for the latest versions of the Linux kernel

Linux version No. of files1 Rows of source2 (Without documentation) Days No. of commits3 Changes4
2.6.29 26668 11010647
(9871260)
89 11718 10933 files changed
1347290 insertions(+)
532055 deletions(-)
2.6.30 27879 11637173
(10419567)
78 11989 10259 files changed
1086737 insertions(+)
460298 deletions(-)
2.6.31 29111 12046317
(10778469)
92 10883 8938 files changed
914135 insertions(+)
504980 deletions(-)
2.6.32 30485 12606910
(11242136)
84 10998 10315 files changed
1092987 insertions(+)
530428 deletions(-)
2.6.33 31565 12990041
(11564768)
83 10871 9673 files changed
859458 insertions(+)
479452 deletions(-)
2.6.34 32297 13320934
(11861616)
82 9443 11154 files changed
609584 insertions(+)
278958 deletions(-)
2.6.35 33316 13545604
(12250679)
77 9801 8889 files changed
691927 insertions(+)
467252 deletions(-)
¹ find . -type f -not -regex '\./\.git/.*' | wc -l
² find . -type f -not -regex '\./\.git.*' | xargs cat | wc -l (find . -name *.[hcS] -not -regex '\./\.git.*' | xargs cat | wc -l)
³ git-log --no-merges --pretty=oneline v2.6.(x-1)..v2.6.(x) | wc -l
⁴ git diff --shortstat v2.6.(x-1)..v2.6.(x)

Which developers and vendors contributed what and various other statistics about the changes in 2.6.35 are documented in the article "Kernel development statistics for 2.6.35" at LWN.net.

Next: Overview of 2.6.35 and the 2.6.36 outlook

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