K 10
svn:author
V 4
jeff
K 8
svn:date
V 27
2015-10-14T02:10:07.313066Z
K 7
svn:log
V 799
Parallelize the buffer cache and rewrite getnewbuf().  This results in a
8x performance improvement in a micro benchmark on a 4 socket machine.

 - Get buffer headers from a per-cpu uma cache that sits in from of the
   free queue.
 - Use a per-cpu quantum cache in vmem to eliminate contention for kva.
 - Use multiple clean queues according to buffer cache size to eliminate
   clean queue lock contention.
 - Introduce a bufspace daemon that attempts to prevent getnewbuf() callers
   from blocking or doing direct recycling.
 - Close some bufspace allocation races that could lead to endless
   recycling.
 - Further the transition to a more modern style of small functions grouped
   by prefix in order to improve growing complexity.

Sponsored by:	EMC / Isilon
Reviewed by:	kib
Tested by:	pho

END