On Thu, Apr 13, 2017 at 11:19:26AM -0700, Paul E. McKenney wrote: > First get me some system-level data showing that the current layout is > causing a real problem. RCU's fastpath code doesn't come anywhere near > the rcu_node tree, so in the absence of such data, I of course remain > quite doubtful that there is a real need. And painfully aware of the > required increase in complexity. > > But if there is a real need demonstrated by real system-level data, > I will of course make the needed changes, as I have done many times in > the past in response to other requests.
I read what you wrote here: > > > Increasing it reduces the number of rcu_node structures, and thus the > > > number of cache misses during grace-period initialization and cleanup. > > > This has proven necessary in the past on large machines having long > > > memory latencies. And there are starting to be some pretty big machines > > > running in production, and even for typical commerical workloads. to mean you had exactly that pain. Or am I now totally not understanding you?
