[PATCH 10/15] sched/fair: Propagate enqueue flags into place_entity()

From: Peter Zijlstra
Date: Wed May 31 2023 - 08:49:19 EST


This allows place_entity() to consider ENQUEUE_WAKEUP and
ENQUEUE_MIGRATED.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
kernel/sched/fair.c | 10 +++++-----
kernel/sched/sched.h | 1 +
2 files changed, 6 insertions(+), 5 deletions(-)

--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4909,7 +4909,7 @@ static inline void update_misfit_status(
#endif /* CONFIG_SMP */

static void
-place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
+place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
{
u64 vslice = calc_delta_fair(se->slice, se);
u64 vruntime = avg_vruntime(cfs_rq);
@@ -4998,7 +4998,7 @@ place_entity(struct cfs_rq *cfs_rq, stru
* on average, halfway through their slice, as such start tasks
* off with half a slice to ease into the competition.
*/
- if (sched_feat(PLACE_DEADLINE_INITIAL) && initial)
+ if (sched_feat(PLACE_DEADLINE_INITIAL) && (flags & ENQUEUE_INITIAL))
vslice /= 2;

/*
@@ -5021,7 +5021,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, st
* update_curr().
*/
if (curr)
- place_entity(cfs_rq, se, 0);
+ place_entity(cfs_rq, se, flags);

update_curr(cfs_rq);

@@ -5048,7 +5048,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, st
* we can place the entity.
*/
if (!curr)
- place_entity(cfs_rq, se, 0);
+ place_entity(cfs_rq, se, flags);

account_entity_enqueue(cfs_rq, se);

@@ -12053,7 +12053,7 @@ static void task_fork_fair(struct task_s
curr = cfs_rq->curr;
if (curr)
update_curr(cfs_rq);
- place_entity(cfs_rq, se, 1);
+ place_entity(cfs_rq, se, ENQUEUE_INITIAL);
rq_unlock(rq, &rf);
}

--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -2174,6 +2174,7 @@ extern const u32 sched_prio_to_wmult[40
#else
#define ENQUEUE_MIGRATED 0x00
#endif
+#define ENQUEUE_INITIAL 0x80

#define RETRY_TASK ((void *)-1UL)