Linux Kernel News - January and February 2014
I am reporting the Linux project activity for the past two months in this article. Blame it on me being heads down to get some development work done. Without further ado, let's get started on catching up.
Mainline Release (Linus's tree) News
Linux 3.13 was released on Sunday January 19th 2014. Please read What is in Linux 3.13. 3.14-rc5 was released on March 2 2014. Based on the rc release progress so far, it is looking very likely that the Linux 3.14 release will be out before the end of March 2014. Summary of selected git pull requests for 3.14 that made it into 3.14-rc1 are:
- turbostat updates from Len Brown:
A new command line option -s to dump counters
Enhancement to run on Haswell Xeon [HSX]. HSX has a slightly different RAPL support than client HSW, which prevented the previous version of turbostat from running on HSX.
- ARM SoC fixes from Olof Johansson:
Enable new drivers in the defconfigs for platforms that have such devices
Increase coverage of the multi-platform defconfig and some DTS changes that plumbs up some of the devices that now have bindings and driver support.
- ARM64 patches from Catalin Marinas:
Introduction of PTE_WRITE to distinguish between writable but clean and truly read-only pages
- ACPI and power management updates from Rafael Wysocki:
ACPI core changes to make it create a struct acpi_device object for every device represented in the ACPI tables during all namespace scans regardless of the current status of that device. This change prevents, ACPI hot-plug operations from erroneously deleting those objects, unless the underlying ACPI tables go away.
A new tool for suspend/resume performance optimization from Todd E Brandt
Init code change to move up early ACPI initialization which should allow the kernel to use ACPI during the time-keeping initialization and possibly simplify the EFI initialization as well - From Chun-Yi Lee
apm-emulation: add hibernation APM events to support suspend2disk - Enhancement to improve hibernation on embedded systems that use hibernation for fast boot. With this change, software components will be notified with APM events to get ready for hibernation and restore the state afterwards. Capturing the apm status about these pm events is necessary help use fast boot while maintaining system state for hibernation and restore. This change adds apm support for suspend to disk.
- Thermal management updates from Zhang Rui:
Representing hardware thermal properties in device tree infrastructure - This work includes the introduction of a device tree bindings for describing the hardware thermal behavior and limits, a parser to read and interpret the data, and build thermal zones and thermal binding parameters. In addition to that three drivers (TI SoC thermal and two hwmon drivers) are converted to use the new representation on sensor devices to serve as an initial validation for the API. This is the first step towards completing the work to identify and convert drivers to use the proposed API and validate it.
Stable release News
Jiri Slaby is taking over the longterm maintenance of the 3.12 stable tree. Greg KH will continue to do the final release to kernel.org. Jiri Slaby is responsible for collecting patches, sending out release candidate announcements. Please read the details 3.12-stable kernel tree being taken over by Jiri Slaby. As of this writing the latest stable releases are as follows:Latest Stable and Extended releases
|Stable 3.13||3.13.6||Not announced|
|Stable 3.12||3.12.14||Not announced|
|Stable 3.11||3.11.10||EOL November 29 2013|
|Longterm 3.10||3.10.33||September 2015|
|Longterm 3.4||3.4.82||October 2014|
|Longterm 3.0||3.0.101||EOL October 22 2013|
|Longterm 2.6.34||126.96.36.199||EOL February 10 2014|
|Extended stable 3.11.y.z||188.8.131.52||Extended Stable|
|Extended stable 3.8.y.z||184.108.40.206||Extended Stable|
|Extended stable 3.5.y.z||220.127.116.11||Extended Stable|
If you ever wondered how these stable releases are managed and how often a new release comes out, here is more detail: Active kernel releases
Linux RT stable releases_ are numerous. Please checkout linux-stable-rt.git for their latest versions.
Where can you find all git trees for Linux releases?
|Stable releases (all)||git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git|
|Linux RT releases||git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git|
|Extended stable releases||git://kernel.ubuntu.com/ubuntu/linux.git|
|Bleeding edge linux-next||git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git|
TCP Fast Open in 3.13 makes establishing a TCP connection much faster by elimination of one round time trip from certain kinds of TCP conversation, which can improve the load speed of web pages.
ARM changes are significant in 3.14-rc1 merge. Several new devices can now be enabled and increased coverage of the multi-platform defconfig and some DTS changes that plumbs up some of the devices that now have bindings and driver support. Multi-platform configurations coupled with DTS changes help support on multiple platforms with the a common driver code as opposed to requiring device tree device enumeration and special handling for platform to platform variations in how devices are enumerated. This is good news for ARM evolution as it is beginning to add support for PCI devices.
Enhancement to improve hibernation on embedded systems that use hibernation for fast boot is good for mobile and embedded space. Who would want their mobiles coming out of hibernation behaving weird?
In Linux 3.14-rc5 announcement, Linus Torvalds said "Another week, another rc. Things were fairly calm, and fairly normal.". Based on that, barring any last minutes nasty surprises, Linux 3.14 should come out in the next 2-3 weeks. After that as usual the next merge window will open for 3.15-rc1.
If anybody is wondering, what is changing with Jiri Slaby taking over the longterm maintenance of 3.12, please rest assured that it will be maintained the same way it is done today. Jiri Slaby will collect patches and send out release candidates. I volunteered to keep testing the 3.12 release candidates, and Guenter Roeck has volunteered to keep running his build tests on the patch queue for 3.12. Greg KH will do the final release to kernel.org.
Shuah Khan is a Senior Linux Kernel Developer at Samsung's Open Source Group.
|Red Hat Enterprise Linux 7.1 beta available on IBM Power Platform||Jan 23, 2015|
|Designing with Linux||Jan 22, 2015|
|Wondershaper—QOS in a Pinch||Jan 21, 2015|
|Ideal Backups with zbackup||Jan 19, 2015|
|Non-Linux FOSS: Animation Made Easy||Jan 14, 2015|
|Internet of Things Blows Away CES, and it May Be Hunting for YOU Next||Jan 12, 2015|
- Designing with Linux
- Wondershaper—QOS in a Pinch
- Red Hat Enterprise Linux 7.1 beta available on IBM Power Platform
- Internet of Things Blows Away CES, and it May Be Hunting for YOU Next
- Ideal Backups with zbackup
- Slow System? iotop Is Your Friend
- New Products
- 2014 Book Roundup
- Hats Off to Mozilla
- January 2015 Issue of Linux Journal: Security
Editorial Advisory Panel
Thank you to our 2014 Editorial Advisors!
- Jeff Parent
- Brad Baillio
- Nick Baronian
- Steve Case
- Chadalavada Kalyana
- Caleb Cullen
- Keir Davis
- Michael Eager
- Nick Faltys
- Dennis Frey
- Philip Jacob
- Jay Kruizenga
- Steve Marquez
- Dave McAllister
- Craig Oda
- Mike Roberts
- Chris Stark
- Patrick Swartz
- David Lynch
- Alicia Gibb
- Thomas Quinlan
- Carson McDonald
- Kristen Shoemaker
- Charnell Luchich
- James Walker
- Victor Gregorio
- Hari Boukis
- Brian Conner
- David Lane