On Thu, Jul 18, 2019 at 04:27:19PM -0700, Tim Chen wrote: > > > On 7/18/19 3:07 AM, Aaron Lu wrote: > > On Wed, Jun 19, 2019 at 02:33:02PM -0400, Julien Desfossez wrote: > > > > > With the below patch on top of v3 that makes use of util_avg to decide > > which task win, I can do all 8 steps and the final scores of the 2 > > workloads are: 1796191 and 2199586. The score number are not close, > > suggesting some unfairness, but I can finish the test now... > > Aaron, > > Do you still see high variance in terms of workload throughput that > was a problem with the previous version?
Any suggestion how to measure this? It's not clear how Aubrey did his test, will need to take a look at sysbench. > > > > > > } > > + > > +bool cfs_prio_less(struct task_struct *a, struct task_struct *b) > > +{ > > + struct sched_entity *sea = &a->se; > > + struct sched_entity *seb = &b->se; > > + bool samecore = task_cpu(a) == task_cpu(b); > > > Probably "samecpu" instead of "samecore" will be more accurate. > I think task_cpu(a) and task_cpu(b) > can be different, but still belong to the same cpu core. Right, definitely, guess I'm brain damaged. > > > + struct task_struct *p; > > + s64 delta; > > + > > + if (samecore) { > > + /* vruntime is per cfs_rq */ > > + while (!is_same_group(sea, seb)) { > > + int sea_depth = sea->depth; > > + int seb_depth = seb->depth; > > + > > + if (sea_depth >= seb_depth) > > Should this be strictly ">" instead of ">=" ? Same depth doesn't necessarily mean same group while the purpose here is to make sure they are in the same cfs_rq. When they are of the same depth but in different cfs_rqs, we will continue to go up till we reach rq->cfs. > > > + sea = parent_entity(sea); > > + if (sea_depth <= seb_depth) > > Should use "<" ? Ditto here. When they are of the same depth but no in the same cfs_rq, both se will move up. > > + seb = parent_entity(seb); > > + } > > + > > + delta = (s64)(sea->vruntime - seb->vruntime); > > + } > > + Thanks.