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In brief

  • The kernel hackers have further reduced the use of the Big Kernel Lock (BKL) in the infrastructure code and in numerous drivers. This brings the developers another step closer to their aim of making the kernel work without this bulky locking mechanism that decreases scalability, and therefore system performance, on standard systems.
  • In certain circumstances, the process scheduler now reduces the competition between kernel threads that are trying to gain exclusive control of a resource which is in use. This causes fewer disruptions to the active process and can considerably improve data throughput (commit, article on LWN.net).
  • Almost a month after the closing of the merge window, the kernel hackers have made a change to the process scheduler to reduce maximum latencies, for instance when other parallel processes are claiming CPU time, especially on desktop systems – this promises to improve response times and is said to make systems appear faster. The discussion preceding the changes and the commit comment provide background information as well as some values measured in a test scenario that show the maximum latency as reduced to almost half of the original amount.
  • With 2.6.36, the kernel hackers hope to have fixed the problem that existed under 2.6.35 and several previous kernels, that in certain circumstances, caused systems to appear extremely slow or occasionally cease to respond altogether while the kernel wrote large amounts of data to a slow storage medium (such as a USB Flash drive) (for instance 1).
  • The new interfaces in 2.6.36 display which PCI / PCIe devices use the power-saving modes of I/O devices and to what extent during runtime; the recently released version 1.13 of PowerTop can already read out, process, and output this data.
  • The ideapad driver for the Lenovo netbooks of the same name has been added to the platform subsystem.
  • The new scroll acceleration in the driver for Magic Mouse, which sometimes confuses users, is now disabled in standard settings and has to be enabled via a module parameter.

Facts and figures for the latest versions of the Linux kernel

Linux
Version
Files1 Source lines2 Days 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(-)
2.6.36 34301 13499457
(12539782)
80 9501 9202 files changed
582139 insertions(+)
628362 deletions(-)
¹ find . -type f -not -regex '\./\.git/.*' | wc -l
² (Without documentation): 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)

Next: Overview of 2.6.36 & the 2.6.37 outlook

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