[PATCH v3] sched/fair: Remove cfs_rq::nr_spread_over and cfs_rq::exec_clock

From: Chuyi Zhou
Date: Fri Jul 19 2024 - 23:19:48 EST


nr_spread_over tracks the number of instances where the difference
between a scheduling entity's virtual runtime and the minimum virtual
runtime in the runqueue exceeds three times the scheduler latency,
indicating significant disparity in task scheduling.
Commit 5e963f2bd465 ("sched/fair: Commit to EEVDF") removed its usage.

cfs_rq->exec_clock was used to account for time spent executing tasks.
Commit 5d69eca542ee ("sched: Unify runtime accounting across classes")
removed its usage.

cfs_rq::nr_spread_over and cfs_rq::exec_clock are not used anymore in
eevdf. Remove them from struct cfs_rq.

Signed-off-by: Chuyi Zhou <zhouchuyi@xxxxxxxxxxxxx>
Acked-by: Vishal Chourasia <vishalc@xxxxxxxxxxxxx>
Reviewed-by: Chengming Zhou <chengming.zhou@xxxxxxxxx>
Reviewed-by: K Prateek Nayak <kprateek.nayak@xxxxxxx>
---
Changes in v3:
Fix the commit description style suggested by Prateek.

Changes in v2:
Add more description of nr_spread_over and exec_clock
suggested by Vishal.
---
kernel/sched/debug.c | 4 ----
kernel/sched/sched.h | 6 ------
2 files changed, 10 deletions(-)

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index c1eb9a1afd13..90c4a9998377 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -641,8 +641,6 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
SEQ_printf(m, "\n");
SEQ_printf(m, "cfs_rq[%d]:\n", cpu);
#endif
- SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "exec_clock",
- SPLIT_NS(cfs_rq->exec_clock));

raw_spin_rq_lock_irqsave(rq, flags);
root = __pick_root_entity(cfs_rq);
@@ -669,8 +667,6 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
SPLIT_NS(right_vruntime));
spread = right_vruntime - left_vruntime;
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "spread", SPLIT_NS(spread));
- SEQ_printf(m, " .%-30s: %d\n", "nr_spread_over",
- cfs_rq->nr_spread_over);
SEQ_printf(m, " .%-30s: %d\n", "nr_running", cfs_rq->nr_running);
SEQ_printf(m, " .%-30s: %d\n", "h_nr_running", cfs_rq->h_nr_running);
SEQ_printf(m, " .%-30s: %d\n", "idle_nr_running",
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 4c36cc680361..8a071022bdec 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -599,7 +599,6 @@ struct cfs_rq {
s64 avg_vruntime;
u64 avg_load;

- u64 exec_clock;
u64 min_vruntime;
#ifdef CONFIG_SCHED_CORE
unsigned int forceidle_seq;
@@ -619,10 +618,6 @@ struct cfs_rq {
struct sched_entity *curr;
struct sched_entity *next;

-#ifdef CONFIG_SCHED_DEBUG
- unsigned int nr_spread_over;
-#endif
-
#ifdef CONFIG_SMP
/*
* CFS load tracking
@@ -1158,7 +1153,6 @@ struct rq {
/* latency stats */
struct sched_info rq_sched_info;
unsigned long long rq_cpu_time;
- /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */

/* sys_sched_yield() stats */
unsigned int yld_count;
--
2.20.1