[PATCH v2 2/5] sched/eevdf: Share the slice protection calculation

[Christian Loehle]

set_protect_slice() and update_protect_slice() duplicate the slice
selection and vprot limiting rules. Merge the calculation into
set_protect_slice().

No functional change intended.

Suggested-by: Elif Topuz <elif.topuz@xxxxxxx>
Signed-off-by: Christian Loehle <christian.loehle@xxxxxxx>
---
 kernel/sched/fair.c | 39 +++++++++++++++------------------------
 1 file changed, 15 insertions(+), 24 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 85bf02570473..3f881ded5457 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1119,43 +1119,34 @@ struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq)
  * When run to parity is disabled, we give a minimum quantum to the running
  * entity to ensure progress.
  */
-static inline void set_protect_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
+static inline void set_protect_slice(struct cfs_rq *cfs_rq, struct sched_entity *se,
+				     bool update)
 {
 	u64 slice = normalized_sysctl_sched_base_slice;
+	u64 vruntime = se->vruntime;
 	u64 vprot = se->deadline;
 
+	if (update) {
+		vruntime = min_vruntime(se->vruntime, avg_vruntime(cfs_rq));
+		vprot = se->vprot;
+	}
+
 	if (sched_feat(RUN_TO_PARITY))
 		slice = cfs_rq_min_slice(cfs_rq);
 
-	slice = min(slice, se->slice);
+	if (!update)
+		slice = min(slice, se->slice);
 
 	/* If there are shorter slices than se's one */
-	if (slice != se->slice) {
-		vprot = min_vruntime(vprot, se->vruntime + calc_delta_fair(slice, se));
-		if (sched_feat(PREEMPT_SHORT))
+	if (update || slice != se->slice) {
+		vprot = min_vruntime(vprot, vruntime + calc_delta_fair(slice, se));
+		if (sched_feat(PREEMPT_SHORT) && slice != se->slice)
 			vprot = min_vruntime(vprot, ineligible_vruntime(cfs_rq));
 	}
 
 	se->vprot = vprot;
 }
 
-static inline void update_protect_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
-	u64 vruntime = min_vruntime(se->vruntime, avg_vruntime(cfs_rq));
-	u64 slice = normalized_sysctl_sched_base_slice;
-	u64 vprot;
-
-	if (sched_feat(RUN_TO_PARITY))
-		slice = cfs_rq_min_slice(cfs_rq);
-
-	vprot = min_vruntime(se->vprot, vruntime + calc_delta_fair(slice, se));
-
-	if (sched_feat(PREEMPT_SHORT) && slice != se->slice)
-		vprot = min_vruntime(vprot, ineligible_vruntime(cfs_rq));
-
-	se->vprot = vprot;
-}
-
 static inline bool protect_slice(struct sched_entity *se)
 {
 	return vruntime_cmp(se->vruntime, "<", se->vprot);
@@ -10268,7 +10259,7 @@ static void wakeup_preempt_fair(struct rq *rq, struct task_struct *p, int wake_f
 	if (sched_feat(RUN_TO_PARITY)) {
 		u64 old_vprot = se->vprot;
 
-		update_protect_slice(cfs_rq, se);
+		set_protect_slice(cfs_rq, se, true);
 		if (hrtick_enabled_fair(rq) && se->vprot != old_vprot) {
 			/* The enqueue may have armed the timer before this update. */
 			if (protect_slice(se))
@@ -15576,7 +15567,7 @@ static void set_next_task_fair(struct rq *rq, struct task_struct *p, enum snt_e
 	if (on_rq) {
 		reweight_eevdf(cfs_rq, se, weight, se->on_rq);
 		if (first)
-			set_protect_slice(cfs_rq, se);
+			set_protect_slice(cfs_rq, se, false);
 	}
 
 	if (task_on_rq_queued(p)) {
-- 
2.34.1