Commit 7c7ad626 authored by Vincent Guittot's avatar Vincent Guittot Committed by Peter Zijlstra
Browse files

sched/fair: Keep load_avg and load_sum synced 



when removing a cfs_rq from the list we only check _sum value so we must
ensure that _avg and _sum stay synced so load_sum can't be null whereas
load_avg is not after propagating load in the cgroup hierarchy.

Use load_avg to compute load_sum similarly to what is done for util_sum
and runnable_sum.

Fixes: 0e2d2aaa ("sched/fair: Rewrite PELT migration propagation")
Reported-by: default avatarOdin Ugedal <odin@uged.al>
Signed-off-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarOdin Ugedal <odin@uged.al>
Link: https://lkml.kernel.org/r/20210527122916.27683-2-vincent.guittot@linaro.org
parent 8124c8a6

kernel/sched/fair.c

+5 −6
Original line number Diff line number Diff line
@@ -3499,10 +3499,9 @@ update_tg_cfs_runnable(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cf 
static inline void

update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq *gcfs_rq)

{

	long delta_avg, running_sum, runnable_sum = gcfs_rq->prop_runnable_sum;

	long delta, running_sum, runnable_sum = gcfs_rq->prop_runnable_sum;

	unsigned long load_avg;

	u64 load_sum = 0;

	s64 delta_sum;

	u32 divider;



	if (!runnable_sum)
@@ -3549,13 +3548,13 @@ update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cfs_rq 
	load_sum = (s64)se_weight(se) * runnable_sum;

	load_avg = div_s64(load_sum, divider);



	delta_sum = load_sum - (s64)se_weight(se) * se->avg.load_sum;

	delta_avg = load_avg - se->avg.load_avg;

	delta = load_avg - se->avg.load_avg;



	se->avg.load_sum = runnable_sum;

	se->avg.load_avg = load_avg;

	add_positive(&cfs_rq->avg.load_avg, delta_avg);

	add_positive(&cfs_rq->avg.load_sum, delta_sum);



	add_positive(&cfs_rq->avg.load_avg, delta);

	cfs_rq->avg.load_sum = cfs_rq->avg.load_avg * divider;

}



static inline void add_tg_cfs_propagate(struct cfs_rq *cfs_rq, long runnable_sum)