Hi Steve, On 06/12/2018 21:28, Steve Sistare wrote: [...] > @@ -3724,6 +3725,28 @@ static inline void update_misfit_status(struct > task_struct *p, struct rq *rq) > rq->misfit_task_load = task_h_load(p); > } > > +static void overload_clear(struct rq *rq)
Nitpicky nit: cfs_overload_{clear, set} might be a bit better, just to explicitly differentiate this from rq->rd->overload. Although I suppose the naming problem will show up again if/when you try to expand this to other classes... > +{ > + struct sparsemask *overload_cpus; > + > + rcu_read_lock(); > + overload_cpus = rcu_dereference(rq->cfs_overload_cpus); > + if (overload_cpus) > + sparsemask_clear_elem(overload_cpus, rq->cpu); > + rcu_read_unlock(); > +} > + > +static void overload_set(struct rq *rq) > +{ > + struct sparsemask *overload_cpus; > + > + rcu_read_lock(); > + overload_cpus = rcu_dereference(rq->cfs_overload_cpus); > + if (overload_cpus) > + sparsemask_set_elem(overload_cpus, rq->cpu); > + rcu_read_unlock(); > +} > + > #else /* CONFIG_SMP */ > > #define UPDATE_TG 0x0 [...] > @@ -4468,8 +4495,12 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq) > dequeue = 0; > } > > - if (!se) > + if (!se) { > sub_nr_running(rq, task_delta); > + if (prev_nr >= 2 && prev_nr - task_delta < 2) > + overload_clear(rq); > + > + } Eventually it'd be nice to squash those into {add, sub}_nr_running(), but you already mentioned wanting to stick to CFS for now, so I don't think it's *too* much of a big deal. > > cfs_rq->throttled = 1; > cfs_rq->throttled_clock = rq_clock(rq); > @@ -4499,6 +4530,7 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq) [...]