sched/fair: Remove rq->load

The CFS class is the only one maintaining and using the CPU wide load
(rq->load(.weight)). The last use case of the CPU wide load in CFS's
set_next_entity() can be replaced by using the load of the CFS class
(rq->cfs.load(.weight)) instead.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190424084556.604-1-dietmar.eggemann@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/debug.c

@@ -656,8 +656,6 @@ do {									\
 	SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))
 
 	P(nr_running);
-	SEQ_printf(m, "  .%-30s: %lu\n", "load",
-		   rq->load.weight);
 	P(nr_switches);
 	P(nr_load_updates);
 	P(nr_uninterruptible);

kernel/sched/fair.c

@@ -2686,8 +2686,6 @@ static void
 account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
 	update_load_add(&cfs_rq->load, se->load.weight);
-	if (!parent_entity(se))
-		update_load_add(&rq_of(cfs_rq)->load, se->load.weight);
 #ifdef CONFIG_SMP
 	if (entity_is_task(se)) {
 		struct rq *rq = rq_of(cfs_rq);
@@ -2703,8 +2701,6 @@ static void
 account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
 	update_load_sub(&cfs_rq->load, se->load.weight);
-	if (!parent_entity(se))
-		update_load_sub(&rq_of(cfs_rq)->load, se->load.weight);
 #ifdef CONFIG_SMP
 	if (entity_is_task(se)) {
 		account_numa_dequeue(rq_of(cfs_rq), task_of(se));
@@ -4100,7 +4096,8 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
 	 * least twice that of our own weight (i.e. dont track it
 	 * when there are only lesser-weight tasks around):
 	 */
-	if (schedstat_enabled() && rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
+	if (schedstat_enabled() &&
+	    rq_of(cfs_rq)->cfs.load.weight >= 2*se->load.weight) {
 		schedstat_set(se->statistics.slice_max,
 			max((u64)schedstat_val(se->statistics.slice_max),
 			    se->sum_exec_runtime - se->prev_sum_exec_runtime));

kernel/sched/sched.h

@@ -830,8 +830,6 @@ struct rq {
 	atomic_t nohz_flags;
 #endif /* CONFIG_NO_HZ_COMMON */
 
-	/* capture load from *all* tasks on this CPU: */
-	struct load_weight	load;
 	unsigned long		nr_load_updates;
 	u64			nr_switches;