The following commit has been merged into the sched/core branch of tip:
Commit-ID: dae4320b29f0bbdae93f7c1f6f80b19f109ca0bc
Gitweb: https://git.kernel.org/tip/dae4320b29f0bbdae93f7c1f6f80b19f109ca0bc
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Wed, 14 Aug 2024 00:25:50 +02:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Tue, 03 Sep 2024 15:26:30 +02:00
sched: Fixup set_next_task() implementations
The rule is that:
pick_next_task() := pick_task() + set_next_task(.first = true)
Turns out, there's still a few things in pick_next_task() that are
missing from that combination.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240813224015.724111109@xxxxxxxxxxxxx
---
kernel/sched/deadline.c | 6 ++--
kernel/sched/fair.c | 62 ++++++++++++++++++++--------------------
2 files changed, 34 insertions(+), 34 deletions(-)
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 2e84037..f7ac7cf 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -2386,6 +2386,9 @@ static void set_next_task_dl(struct rq *rq, struct task_struct *p, bool first)
update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 0);
deadline_queue_push_tasks(rq);
+
+ if (hrtick_enabled(rq))
+ start_hrtick_dl(rq, &p->dl);
}
static struct sched_dl_entity *pick_next_dl_entity(struct dl_rq *dl_rq)
@@ -2452,9 +2455,6 @@ static struct task_struct *pick_next_task_dl(struct rq *rq)
if (!p->dl_server)
set_next_task_dl(rq, p, true);
- if (hrtick_enabled(rq))
- start_hrtick_dl(rq, &p->dl);
-
return p;
}
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 3a3286d..eaeb8b2 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -8760,6 +8760,9 @@ again:
return task_of(se);
}
+static void __set_next_task_fair(struct rq *rq, struct task_struct *p, bool first);
+static void set_next_task_fair(struct rq *rq, struct task_struct *p, bool first);
+
struct task_struct *
pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
{
@@ -8808,33 +8811,17 @@ again:
put_prev_entity(cfs_rq, pse);
set_next_entity(cfs_rq, se);
+
+ __set_next_task_fair(rq, p, true);
}
- goto done;
+ return p;
+
simple:
#endif
if (prev)
put_prev_task(rq, prev);
-
- for_each_sched_entity(se)
- set_next_entity(cfs_rq_of(se), se);
-
-done: __maybe_unused;
-#ifdef CONFIG_SMP
- /*
- * Move the next running task to the front of
- * the list, so our cfs_tasks list becomes MRU
- * one.
- */
- list_move(&p->se.group_node, &rq->cfs_tasks);
-#endif
-
- if (hrtick_enabled_fair(rq))
- hrtick_start_fair(rq, p);
-
- update_misfit_status(p, rq);
- sched_fair_update_stop_tick(rq, p);
-
+ set_next_task_fair(rq, p, true);
return p;
idle:
@@ -13145,12 +13132,7 @@ static void switched_to_fair(struct rq *rq, struct task_struct *p)
}
}
-/* Account for a task changing its policy or group.
- *
- * This routine is mostly called to set cfs_rq->curr field when a task
- * migrates between groups/classes.
- */
-static void set_next_task_fair(struct rq *rq, struct task_struct *p, bool first)
+static void __set_next_task_fair(struct rq *rq, struct task_struct *p, bool first)
{
struct sched_entity *se = &p->se;
@@ -13163,6 +13145,27 @@ static void set_next_task_fair(struct rq *rq, struct task_struct *p, bool first)
list_move(&se->group_node, &rq->cfs_tasks);
}
#endif
+ if (!first)
+ return;
+
+ SCHED_WARN_ON(se->sched_delayed);
+
+ if (hrtick_enabled_fair(rq))
+ hrtick_start_fair(rq, p);
+
+ update_misfit_status(p, rq);
+ sched_fair_update_stop_tick(rq, p);
+}
+
+/*
+ * Account for a task changing its policy or group.
+ *
+ * This routine is mostly called to set cfs_rq->curr field when a task
+ * migrates between groups/classes.
+ */
+static void set_next_task_fair(struct rq *rq, struct task_struct *p, bool first)
+{
+ struct sched_entity *se = &p->se;
for_each_sched_entity(se) {
struct cfs_rq *cfs_rq = cfs_rq_of(se);
@@ -13172,10 +13175,7 @@ static void set_next_task_fair(struct rq *rq, struct task_struct *p, bool first)
account_cfs_rq_runtime(cfs_rq, 0);
}
- if (!first)
- return;
-
- SCHED_WARN_ON(se->sched_delayed);
+ __set_next_task_fair(rq, p, first);
}
void init_cfs_rq(struct cfs_rq *cfs_rq)
|