On Sat, Jun 25, 2022 at 08:12:09AM +0900, Akira Yokosawa wrote: > Hi Paul, > > I find the analogy of Figure 7.11 hard to grasp. > > Whether a lock is global or per-instance, the cost of locking > (saw kerf) is observed only when a CPU/thread does the locking > operation. > > In this figure, does each board represent data elements, not a > CPU/thread? If this is the case, what does the waste of "saw kerf" > mean? > > What am I missing? > > (I hope I am clear enough on what I don't get...) It might well be that I am getting too excited about this one. ;-) Maybe I need to drop it. At the very least, I need to much more clearly explain it. But... Each board represents one lock. The "saw kerf" is the time lost when releasing that lock and someone else immediately acquiring it. Does that help? Thanx, Paul
