Searching for a free block in the range manager may in some situations be a lenghty operation, and we want to avoid holding the global lru lock during that time. Instead use a per-manager spinlock. This leaves the global lru lock for quick lru list and swap list manipulation only, including list manipulation associated with reserving buffer objects. Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com> Signed-off-by: Dave Airlie <airlied@redhat.com>