15 Sep
2016
15 Sep
'16
1:01 p.m.
On 15 September 2016 at 14:55, Peter Zijlstra peterz@infradead.org wrote:
On Mon, Sep 12, 2016 at 09:47:49AM +0200, Vincent Guittot wrote: +/* Take into account change of utilization of a child task group */
+static inline void +update_tg_cfs_util(struct cfs_rq *cfs_rq, struct sched_entity *se) +{
struct cfs_rq *gcfs_rq = group_cfs_rq(se);long delta = gcfs_rq->avg.util_avg - se->avg.util_avg;/* Nothing to update */if (!delta)return;/* Set new sched_entity's utilizaton */se->avg.util_avg = gcfs_rq->avg.util_avg;se->avg.util_sum = se->avg.util_avg * LOAD_AVG_MAX;/* Update parent cfs_rq utilization */cfs_rq->avg.util_avg = max_t(long, cfs_rq->avg.util_avg + delta, 0);This..
cfs_rq->avg.util_sum = cfs_rq->avg.util_avg * LOAD_AVG_MAX;+}
+/* Take into account change of load of a child task group */ +static inline void +update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se) +{
struct cfs_rq *gcfs_rq = group_cfs_rq(se);long delta, load = gcfs_rq->avg.load_avg;/* If the load of group cfs_rq is null, the load of the* sched_entity will also be null so we can skip the formula*/if (load) {long tg_load;/* Get tg's load and ensure tg_load > 0 */tg_load = atomic_long_read(&gcfs_rq->tg->load_avg) + 1;/* Ensure tg_load >= load and updated with current load*/tg_load -= gcfs_rq->tg_load_avg_contrib;tg_load += load;/* scale gcfs_rq's load into tg's shares*/load *= scale_load_down(gcfs_rq->tg->shares);load /= tg_load;/** we need to compute a correction term in the case that the* task group is consuming <1 cpu so that we would contribute* the same load as a task of equal weight.*/if (tg_load < scale_load_down(gcfs_rq->tg->shares)) {load *= tg_load;load /= scale_load_down(gcfs_rq->tg->shares);}}delta = load - se->avg.load_avg;/* Nothing to update */if (!delta)return;/* Set new sched_entity's load */se->avg.load_avg = load;se->avg.load_sum = se->avg.load_avg * LOAD_AVG_MAX;/* Update parent cfs_rq load */cfs_rq->avg.load_avg = max_t(long, cfs_rq->avg.load_avg + delta, 0);And this..
cfs_rq->avg.load_sum = cfs_rq->avg.load_avg * LOAD_AVG_MAX;+}
Re-introduce the issue from: 897418922215 ("sched/fair: Fix cfs_rq avg tracking underflow").
Yes sorry, i forgot this point. I will use sub_positive instead