last week's summary
As of this writing, almost 8,800 non-merge changesets have been pulled into
the mainline kernel for the 3.3 development cycle - 2,900 since
. The pace of the merge
window clearly slowed in its second week, but there were still a number of
interesting changes merged.
User-visible changes merged since last week include:
- The kernel has gained the ability to verify RSA digital signatures.
The extended verification module (EVM) makes use of this capability.
- The slab allocator supports a new slab_max_order= boot
parameter controlling the maximum size of a slab. Setting it to a
larger number may increase memory efficiency at the cost of increasing
the probability of allocation failures.
- The ALSA core has gained support for compressed audio on devices that
are able to handle it.
- There have been some significant changes made to the memory compaction
code to avoid the lengthy stalls experienced by some users when
writing data to slow devices (USB keys, for example). This problem
was described in this article, but the
solution has evolved considerably. By making a number of changes to
how compaction works, the memory management hackers (and Mel Gorman in
particular) were able to avoid disabling synchronous compaction, which
had the unfortunate effect of reducing huge page usage. See this
commit for a lot of information on how this problem was addressed.
- There is a new "charger manager" subsystem intended for use with
batteries that must be monitored occasionally, even when the system is
suspended. The charger manager can partially resume the system as
needed to poll the battery, then immediately re-suspend afterward.
for more information.
- The Btrfs balancing/restriping code has been reworked to allow a lot
more flexibility in how a volume is rearranged. Restriping operations
can now be paused, canceled, or resumed after a crash.
- The audit subsystem is now supported on the ARM architecture.
- New device drivers include:
- Systems and processors:
Renesas R8A7740 CPUs,
R-Car H1 (R8A77790) processors,
NetLogic DB1300 boards,
Ubiquiti Networks XM (rev 1.0) boards,
Atheros AP121 reference boards, and
Netlogic XLP SoC and systems.
- Audio: Realtek ALC5632 codecs and
Cirrus Logic CS42L73 codecs.
- Block: Micron PCIe SSD cards and solid-state drives
supporting the NVM Express standard.
TI TWL4030 battery chargers,
Dialog DA9052 battery chargers,
Maxim MAX8997 MUIC devices,
Samsung Electronics S5M multifunction devices, and
CSR SiRFprimaII DMA engines.
- Video4Linux: Samsung S5P and EXYNOS4 G2D 2d graphics
remote controls using the Sanyo protocol,
Austria Microsystems AS3645A and LM3555 flash controllers,
Microtune MT2063 silicon IF tuners,
Jellin JL2005B, JL2005C, or JL2005D-based cameras,
HDIC HD29L2 demodulators, and
Samsung S5P/Exynos4 JPEG codecs.
Changes visible to kernel developers include:
- The memory control group naturalization
patches have been merged. These patches eliminate the
double-tracking of memory and, thus, substantially reduce the overhead
associated with the memory controller.
- The framebuffer device subsystem has a new FOURCC-based configuration
API; see Documentation/fb/api.txt for
- The Btrfs filesystem has gained an integrity checking tool that
monitors traffic to the storage device and looks for operations that
could leave the filesystem corrupted if the system fails at the wrong
time. See the comments at the top of fs/btrfs/check-integrity.c for
The 3.3-rc1 release can be expected at almost any point; after that, the
stabilization process begins for the 3.3 development
cycle. If the usual timing holds (and it almost always does anymore), the
final 3.3 kernel release can be expected in the second half of March.
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