Re: [patch] sched: fix inconsistency when redistribute per-cpu tg->cfs_rq shares.

> diff --git a/kernel/sched.c b/kernel/sched.c > index 9b1e793..1ff78b6 100644 > --- a/kernel/sched.c > +++ b/kernel/sched.c > @@ -1473,27 +1473,13 @@ static void > update_group_shares_cpu(struct task_group *tg, int cpu, > unsigned long sd_shares, unsigned long sd_rq_weight) > { > - int boost = 0; > unsigned long shares; > unsigned long rq_weight; > > if (!tg->se[cpu]) > return; > > - rq_weight = tg->cfs_rq[cpu]->load.weight; > - > - /* > - * If there are currently no tasks on the cpu pretend there is one of > - * average load so that when a new task gets to run here it will not > - * get delayed by group starvation. > - */ > - if (!rq_weight) { > - boost = 1; > - rq_weight = NICE_0_LOAD; > - } > - > - if (unlikely(rq_weight > sd_rq_weight)) > - rq_weight = sd_rq_weight; > + rq_weight = tg->cfs_rq[cpu]->rq_weight; > > /* > * \Sum shares * rq_weight > @@ -1501,7 +1487,7 @@ update_group_shares_cpu > * \Sum rq_weight > * > */ > - shares = (sd_shares * rq_weight) / (sd_rq_weight + 1); > + shares = (sd_shares * rq_weight) / sd_rq_weight; > shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); > > if (abs(shares - tg->se[cpu]->load.weight) > > @@ -1510,11 +1496,7 @@ update_group_shares_cpu > unsigned long flags; > > spin_lock_irqsave(&rq->lock, flags); > - /* > - * record the actual number of shares, not the boosted amount. > - */ > - tg->cfs_rq[cpu]->shares = boost ? 0 : shares; > - tg->cfs_rq[cpu]->rq_weight = rq_weight; > + tg->cfs_rq[cpu]->shares = shares; > > __set_se_shares(tg->se[cpu], shares); > spin_unlock_irqrestore(&rq->lock, flags); > @@ -1528,13 +1510,23 @@ update_group_shares_cpu > */ > static int tg_shares_up(struct task_group *tg, void *data) > { > - unsigned long rq_weight = 0; > + unsigned long weight, rq_weight = 0; > unsigned long shares = 0; > struct sched_domain *sd = data; > int i; > > for_each_cpu_mask(i, sd->span) { > - rq_weight += tg->cfs_rq[i]->load.weight; > + /* > + * If there are currently no tasks on the cpu pretend there > + * is one of average load so that when a new task gets to > + * run here it will not get delayed by group starvation. > + */ > + weight = tg->cfs_rq[i]->load.weight; > + if (!weight) > + weight = NICE_0_LOAD; > + > + tg->cfs_rq[i]->rq_weight = weight; > + rq_weight += weight; > shares += tg->cfs_rq[i]->shares; > } > > @@ -1544,9 +1536,6 @@ static int tg_shares_up > if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) > shares = tg->shares; > > - if (!rq_weight) > - rq_weight = cpus_weight(sd->span) * NICE_0_LOAD; > - > for_each_cpu_mask(i, sd->span) > update_group_shares_cpu(tg, i, shares, rq_weight);