Messages in this thread | | | Date | Fri, 11 Sep 2015 16:13:55 -0700 | From | Davidlohr Bueso <> | Subject | Re: [PATCH v6 4/6] locking/pvqspinlock: Collect slowpath lock statistics |
| |
On Fri, 11 Sep 2015, Waiman Long wrote:
>A sample of statistics counts after system bootup (with vCPU >overcommit) was: > >hash_hops_count=9001 >kick_latencies=138047878 >kick_unlock_count=9001 >kick_wait_count=9000 >spurious_wakeup=3 >wait_again_count=2 >wait_head_count=10 >wait_node_count=8994 >wake_latencies=713195944
Any reason you chose not to make the stats per-cpu? The locking numbers don't have to be exact, so you can easily get away with it and suffer from much less overhead that resorting to atomics. Obviously assuming that reading/collecting the stats is done infrequently, such as between workloads or at bootup as you did.
Thanks, Davidlohr
| |