2.6.39 merge window, part 2
last week's 2.6.39 merge
As of this writing, some 5,500 non-merge changesets have been merged into
the mainline since
. A wide-ranging set of new features, cleanups, and
performance improvements has been added to the kernel. Some of the more
significant user-visible changes include:
Changes visible to kernel developers include:
- After many years of work by a large number of developers, the big
kernel lock has
been removed from the kernel.
- The dynamic debug mechanism has some
new control flags allowing for
control over whether the function name, line number, module name, and
current thread ID are printed.
- The kernel can export raw DMI table data via sysfs, making it
available in user space without needing to go through
- Network drivers can now enable hardware support for receive flow
steering via the new ndo_rx_flow_steer() method.
- The "pstore" filesystem provides access to platform-specific
persistent storage which can be used to carry information across
- The EXTRA_CFLAGS and EXTRA_AFLAGS makefile variables
have been replaced with ccflags-y, ccflags-m,
asflags-y, and asflags-m.
- kmem_cache_name(), which returned the name of a slab cache,
has been removed from the kernel.
- The SLUB memory allocator now has a lockless fast path for
allocations, speeding performance considerably. "Sadly this
does nothing for the slowpath which is where the main issues with
performance in slub are but the best case performance rises
- Kernel threads can be created on a specific NUMA node with the new
- The new function delete_from_page_cache() does what its name
implies; unlike remove_from_page_cache() (which has now been
deleted), it also decrements
the page's reference count. It thus more closely mirrors
- There is a whole new set of functions which are the preferred way to
convert strings to integer values; see this article for details.
- The new "hwspinlock" framework allows the implementation of
synchronization primitives on systems where different cores are
running different operating systems. See Documentation/hwspinlock.txt for more
If the usual two-weeks rule holds, the 2.6.39 merge window can be expected
to close on March 28. Watch this space next week for a summary of the
final changes merged for this development cycle.
to post comments)