On Mon, 14 May 2018 09:09:07 -0700 "Paul E. McKenney" <[email protected]> wrote:
> On Mon, May 14, 2018 at 04:42:33PM +1000, Nicholas Piggin wrote: > > On Sun, 22 Apr 2018 20:02:58 -0700 > > "Paul E. McKenney" <[email protected]> wrote: > > > > > Hello! > > > > > > This series reduces lock contention on the root rcu_node > > > structure, and is also the first precursor to TBD changes to > > > consolidate the three RCU flavors (RCU-bh, RCU-preempt, and > > > RCU-sched) into one. > > > > Hi Paul, > > > > I've been running your rcu/dev branch and haven't noticed any > > problems yet. The irqsoff latency improvement is a little hard to > > measure because the scheduler, but I've tried turning balancing > > parameters right down and I'm yet to see any sign of RCU in traces > > (down to about 100us on a 176 CPU machine), so that's great. > > Good to hear!!! Yep, as in, various other latencies are down to 100us, and still no sign of RCU, so RCU must be sitting somewhere below that. > > (Not that RCU was ever the worst contributor to latency as I said, > > just that I noticed those couple of traces where it showed up.) > > > > Thanks very much for the fast response, sorry I've taken a while to > > test. > > Would you be willing to give me a Tested-by on that series of patches? Yes of course, for your rcu/dev series Tested-by: Nicholas Piggin <[email protected]> Let me know if you make any other changes you'd like me to test before merge. Thanks, Nick
