Add new lockref infrastructure reference implementation
This introduces a new "lockref" structure that supports the concept of
lockless updates of reference counts that still honor an attached
spinlock.
NOTE! This reference implementation is not the optimized lockless
version, rather it is the fallback implementation using standard
spinlocks. The actual optimized versions will be merged into 3.12, but
I wanted to get the infrastructure in place and document the new
interfaces.
[ Also note that this particular commit is drastically cut-down minimal
version of the original patch by Waiman. In order to properly credit
the original author I'm marking Waiman as the author here, but in the
end this patch bears little resemblance to the patch by Waiman. So
blame any errors on me editing things down to the point where I can
introduce the infrastructure before the merge window for 3.12 actually
opens. - Linus ]
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 file changed