On Thu, May 04, 2017 at 10:49:51AM +0100, Dietmar Eggemann wrote: > On 04/05/17 07:21, Peter Zijlstra wrote: > > On Thu, May 04, 2017 at 07:51:29AM +0200, Peter Zijlstra wrote: > > > >> Urgh, and my numbers were so pretty :/ > > > > Just to clarify on how to run schbench, I limited to a single socket (as > > that is what you have) and set -t to the number of cores in the socket > > (not the number of threads). > > > > Furthermore, my machine is _idle_, if I don't do anything, it doesn't do > > _anything_. > > > > I can't recreate this problem running 'numactl -N 0 ./schbench -m 2 -t > 10 -s 10000 -c 15000 -r 30' on my E5-2690 v2 (IVB-EP, 2 sockets, 10 > cores / socket, 2 threads / core) > > I tried tip/sched/core comparing running in 'cpu:/' and 'cpu:/foo' and
I'm running tip/master (I think, possibly with the numa topology fixes in, which should be no-op on the EP). Also, I run debian sysvinit, so nobody creating cgroups I don't know about. > using your patch on top with all the combinations of {NO_}FUDGE, > {NO_}FUDGE2 with prop_type=shares_avg or prop_type_runnable. > > Where you able to see the issue on tip/sched/core w/o your patch on your > machine? I see the 99.5th percentile shoot up when I run it in a cgroup. With FUDGE2 its all good again like not using cgroups. But yes, last time I played with schbench (when prodding at select_idle_sibling) the thing was finicky too, I never quite got the same numbers Chris did. But in the end we found something that worked at both ends.