On 01/05/2021 16:41, Odin Ugedal wrote:

Hi,

quoted

I think what I see on my Juno running the unfairness_missing_load_decay.sh script is
in sync which what you discussed here:

Thanks for taking a look!

quoted

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 794c2cb945f8..7214e6e89820 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c

@@ -10854,6 +10854,8 @@ static void propagate_entity_cfs_rq(struct sched_entity *se)
                        break;

                update_load_avg(cfs_rq, se, UPDATE_TG);
+               if (!cfs_rq_is_decayed(cfs_rq))
+                       list_add_leaf_cfs_rq(cfs_rq);
        }

}

This might however lead to "loss" at /slice/cg-2/sub and
slice/cg-1/sub in this particular case tho, since
propagate_entity_cfs_rq skips one cfs_rq
by taking the parent of the provided se. The loss in that case would
however not be equally big, but will still often contribute to some
unfairness.

Yeah, that's true.

By moving stopped `stress` tasks into

 /sys/fs/cgroup/cpu/slice/cg-{1,2}/sub

and then into

 /sys/fs/cgroup/cpuset/A

which has a cpuset.cpus {0-1,4-5} not containing the cpus the `stress`
tasks attached {2,3} to and then restart the `stress` tasks again I get:

cfs_rq[1]:/slice/cg-1/sub
  .load_avg                      : 1024
  .removed.load_avg              : 0
  .tg_load_avg_contrib           : 1024  <---
  .tg_load_avg                   : 2047  <---
  .se->avg.load_avg              : 511
cfs_rq[1]:/slice/cg-1
  .load_avg                      : 512
  .removed.load_avg              : 0
  .tg_load_avg_contrib           : 512  <---
  .tg_load_avg                   : 1022 <---
  .se->avg.load_avg              : 512
cfs_rq[1]:/slice
  .load_avg                      : 513
  .removed.load_avg              : 0
  .tg_load_avg_contrib           : 513
  .tg_load_avg                   : 1024
  .se->avg.load_avg              : 512
cfs_rq[5]:/slice/cg-1/sub
  .load_avg                      : 1024
  .removed.load_avg              : 0
  .tg_load_avg_contrib           : 1023 <---
  .tg_load_avg                   : 2047 <---
  .se->avg.load_avg              : 511
cfs_rq[5]:/slice/cg-1
  .load_avg                      : 512
  .removed.load_avg              : 0
  .tg_load_avg_contrib           : 510  <---
  .tg_load_avg                   : 1022 <---
  .se->avg.load_avg              : 511
cfs_rq[5]:/slice
  .load_avg                      : 512
  .removed.load_avg              : 0
  .tg_load_avg_contrib           : 511
  .tg_load_avg                   : 1024
  .se->avg.load_avg              : 510

I saw that your v2 patch takes care of that.