The end of the 4.9 merge window
- The XFS filesystem has gained support for shared extents — ranges of
file data that can be shared between multiple owners — and a
copy-on-write mechanism to manage modifications to those extents.
That, in turn, allows XFS to support copy_file_range() along with
other nice features like data deduplication.
- The NFS server now supports the NFS4.2 COPY operation, allowing file
data to be copied without traveling to the client and back.
- The watchdog subsystem has a new "pretimeout" mechanism to allow the
system to respond just prior to the expiration of a timer. Two new
"governors" are provided; one simply prints a log message, while the
other will panic the system in the hope of generating more useful
information for debugging the problem.
- A set of EXPORT_SYMBOL()
improvements has been merged. It is now possible to place export
directives into assembly code, and the handling of exported symbols in
library objects has been improved. One immediate practical result is
that it is now possible to place all EXPORT_SYMBOL()
directives next to the definition of the symbol that is being
exported. At the moment, checksums (for use with
CONFIG_MODVERSIONS) for assembly symbols are not generated;
that should be fixed in the near future.
- The build system can now use "thin archives" for the creation of
intermediate objects, rather than linking them with
ld -r. A thin archive contains symbol information, but
simply points to the component object files rather than making
copies. The main purpose here seems to be to make the PowerPC build
work more smoothly; see this
commit for some more information.
- The build system can also perform dead code and data elimination.
This option is potentially hazardous, since, without some extra
effort, the linker may see some needed code as being dead, but it can
also reduce the resulting image size considerably.
- There is a new GCC plugin called "latent_entropy", which comes
from the grsecurity/PaX patch set. It will instrument
the kernel in an attempt to collect randomness, especially during the
early bootstrap process.
- New hardware support includes: Loongson 1C processors, Freescale "data patch acceleration architecture" hardware buffer and queue-management subsystems, and Imagination Technologies ASCII LCD displays.
At this point the feature work is done; all that remains is to stabilize
all that new code for the final 4.9 release. If all goes according to the
usual schedule, that release can be expected on December 4 or 11.
| Index entries for this article | |
|---|---|
| Kernel | Releases/4.9 |
Posted Oct 20, 2016 0:32 UTC (Thu)
by zlynx (guest, #2285)
[Link] (1 responses)
Posted Oct 20, 2016 18:23 UTC (Thu)
by bfields (subscriber, #19510)
[Link]
Hopefully it should be an improvement even when it falls back on a read-write loop, as at least the data doesn't have to travel to the client and back.
The end of the 4.9 merge window
The end of the 4.9 merge window