This page is an attempt to track ongoing developments in the Linux development community that have a good chance of appearing in a mainline kernel and/or major distributions sometime in the near future. Your "chief meteorologist" is Jonathan Corbet, Executive Editor at LWN.net. If you have suggestions on improving the forecast (and particularly if you have a project or patchset that you think should be tracked), please add your comments to the Discussion page. There's a blog that reports on the main changes to the forecast. You can view it directly or use a feed reader to subscribe to the blog feed. You can also subscribe directly to the changes feed for this page to see feed all forecast edits.
Current conditions:¬† the 2.6.31 kernel was released on September 9.¬† The 2.6.31 development cycle, lasting exactly three months,¬† saw the addition of almost 11,000 individual changes from over 1100 developers representing almost 200 different companies.¬† 2.6.31 has¬† 408,000 more lines of code than 2.6.30.
Some of the more interesting changes in 2.6.31 include:
- Performance counter support for the x86 and PowerPC architectures.¬† Performance counters have long been an out-of-tree feature; 2.6.31 will finally make this important hardware capability available in the mainline kernel.
- Support for char devices in user space.¬† The immediate application of this feature may be to provide support for the legacy Open Sound System driver architecture.
- Kmemleak, a development tool capable of finding memory leaks in kernel code.¬† Support for profiling the kernel with gcov has also been added.
- fsnotify, a new infrastructure for handling notification of filesystem events.¬† In 2.6.31, fsnotify will provide a unified implementation underlying the inotify and dnotify APIs.¬† In the future, it is intended to support the addition of an API¬†so support malware scanning applications under Linux.
- New support for ATI¬†Radeon graphics chipsets, using kernel mode setting and the (also merged)¬†TTM¬†memory manager.¬† These components should bring much better support for Radeon hardware, but this code remains a work in progress for 2.6.31.
- Storage topology support, which will help Linux provide high-performance support for future storage devices, has been merged.
See this article for more information on where code for the 2.6.31 development cycle came from.
Near-term forecast:¬† the 2.6.32 kernel should be released sometime in late November or (more likely)¬†early December.¬† The merge window for this cycle was closed with the release of 2.6.32-rc1 on September 27.¬† Some features which will appear in 2.6.32 include:
- devtmpfs - an automatic device filesystem designed to improve boot times and reliability.¬† This addition is controversial, so there is a small possibility that it could be reverted.
- Per-BDI¬†writeback threads - a significant scalability improvement for systems with multiple disk drives.
- Quite a few scheduler changes aimed at improving performance and interactivity.
- Intel's TXT¬†integrity management mechanism.
- A¬†new power management core, which will eventually support finer-grained runtime power management (and more efficient power use) on a wide range of systems.
- The HWPOISON¬†subsystem, which makes use of hardware support to add fault tolerance in the face of memory errors.
- Intel graphics chipsets can now perform framebuffer compression.¬† If the contents of the frame buffer compress well, compression can significantly reduce the amount of memory scanning required to keep the display current.¬† That, in turn, can lead to up to 0.5W¬†of saved power.
- Support for a number of new diagnostic tools, including timechart and scheduler latency tracing.
- The kernel shared memory (KSM)¬†subsystem; KSM¬†scans memory for pages with identical content. Duplicate pages are replaced with copy-on-write links, resulting in significant reductions in memory use.
The current development release, as of this writing, is 2.6.32-rc6, released on November 3 (note that, as the result of a silly mistake, the 2.6.32-rc2 release never happened).¬† 2.6.32 is now in the stabilization phase.
The forecast has been divided into a number of specific subject areas.
- Core Kernel Developments: schedulers, real-time support, event management, and memory management.
- Virtualization and containers: Xen, KVM, control groups, etc.
- Filesystems: ext4, btrfs, and other ways of storing data.
- Security: technologies and enhancements for keeping Linux systems secure.
- Networking: Network channels and other technologies for connecting systems together.
- Hardware Support: Topics of interest in hardware support.
- Miscellaneous: Topics which do not fit under any other heading.
- User Space: user-space code which forms an important part of the low-level platform.
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Updated November 11, 2009