On Thu, Dec 12, 2019 at 11:10:31AM +0100, Peter Zijlstra wrote: > @@ -4156,13 +4159,13 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) > if (delta_exec < sysctl_sched_min_granularity) > return; > > - se = __pick_first_entity(cfs_rq); > + se = __pick_next_entity(cfs_rq, NULL); > delta = curr->vruntime - se->vruntime; > > if (delta < 0) > return; What I mean with the below comment is, when this isn't enough, try something like: if (se == cfs_rq->next) ideal_runtime /= 2; to make it yield sooner to 'next' buddies. Sadly, due to the whole cgroup mess, we can't say what actual task is on the end of it (without doing a full hierarchy pick, which is more expensive still). > - if (delta > ideal_runtime) > + if (delta > ideal_runtime) // maybe frob this too ? > resched_curr(rq_of(cfs_rq)); > }