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Message-ID: <20241202174606.4074512-3-vincent.guittot@linaro.org>
Date: Mon, 2 Dec 2024 18:45:57 +0100
From: Vincent Guittot <vincent.guittot@...aro.org>
To: mingo@...hat.com,
peterz@...radead.org,
juri.lelli@...hat.com,
dietmar.eggemann@....com,
rostedt@...dmis.org,
bsegall@...gle.com,
mgorman@...e.de,
vschneid@...hat.com,
linux-kernel@...r.kernel.org
Cc: kprateek.nayak@....com,
pauld@...hat.com,
efault@....de,
luis.machado@....com,
tj@...nel.org,
void@...ifault.com,
Vincent Guittot <vincent.guittot@...aro.org>
Subject: [PATCH 02/11 v3] sched/eevdf: More PELT vs DELAYED_DEQUEUE
From: Peter Zijlstra <peterz@...radead.org>
Vincent and Dietmar noted that while
commit fc1892becd56 ("sched/eevdf: Fixup PELT vs DELAYED_DEQUEUE") fixes
the entity runnable stats, it does not adjust the cfs_rq runnable stats,
which are based off of h_nr_running.
Track h_nr_delayed such that we can discount those and adjust the
signal.
Fixes: fc1892becd56 ("sched/eevdf: Fixup PELT vs DELAYED_DEQUEUE")
Reported-by: Dietmar Eggemann <dietmar.eggemann@....com>
Closes: https://lore.kernel.org/lkml/a9a45193-d0c6-4ba2-a822-464ad30b550e@arm.com/
Reported-by: Vincent Guittot <vincent.guittot@...aro.org>
Closes: https://lore.kernel.org/lkml/CAKfTPtCNUvWE_GX5LyvTF-WdxUT=ZgvZZv-4t=eWntg5uOFqiQ@mail.gmail.com/
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
[ Fixes checkpatch warnings and rebased ]
Signed-off-by: Vincent Guittot <vincent.guittot@...aro.org>
Link: https://lkml.kernel.org/r/20240906104525.GG4928@noisy.programming.kicks-ass.net
Tested-by: K Prateek Nayak <kprateek.nayak@....com>
---
kernel/sched/debug.c | 1 +
kernel/sched/fair.c | 51 +++++++++++++++++++++++++++++++++++++++-----
kernel/sched/pelt.c | 2 +-
kernel/sched/sched.h | 8 +++++--
4 files changed, 54 insertions(+), 8 deletions(-)
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index a48b2a701ec2..a1be00a988bf 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -845,6 +845,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "spread", SPLIT_NS(spread));
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", "h_nr_delayed", cfs_rq->h_nr_delayed);
SEQ_printf(m, " .%-30s: %d\n", "idle_nr_running",
cfs_rq->idle_nr_running);
SEQ_printf(m, " .%-30s: %d\n", "idle_h_nr_running",
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4283c818bbd1..fc69aab57870 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5463,9 +5463,33 @@ static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq);
-static inline void finish_delayed_dequeue_entity(struct sched_entity *se)
+static void set_delayed(struct sched_entity *se)
+{
+ se->sched_delayed = 1;
+ for_each_sched_entity(se) {
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+
+ cfs_rq->h_nr_delayed++;
+ if (cfs_rq_throttled(cfs_rq))
+ break;
+ }
+}
+
+static void clear_delayed(struct sched_entity *se)
{
se->sched_delayed = 0;
+ for_each_sched_entity(se) {
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+
+ cfs_rq->h_nr_delayed--;
+ if (cfs_rq_throttled(cfs_rq))
+ break;
+ }
+}
+
+static inline void finish_delayed_dequeue_entity(struct sched_entity *se)
+{
+ clear_delayed(se);
if (sched_feat(DELAY_ZERO) && se->vlag > 0)
se->vlag = 0;
}
@@ -5495,7 +5519,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
if (cfs_rq->next == se)
cfs_rq->next = NULL;
update_load_avg(cfs_rq, se, 0);
- se->sched_delayed = 1;
+ set_delayed(se);
return false;
}
}
@@ -5909,7 +5933,7 @@ static bool throttle_cfs_rq(struct cfs_rq *cfs_rq)
struct rq *rq = rq_of(cfs_rq);
struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
struct sched_entity *se;
- long task_delta, idle_task_delta, dequeue = 1;
+ long task_delta, idle_task_delta, delayed_delta, dequeue = 1;
long rq_h_nr_running = rq->cfs.h_nr_running;
raw_spin_lock(&cfs_b->lock);
@@ -5942,6 +5966,7 @@ static bool throttle_cfs_rq(struct cfs_rq *cfs_rq)
task_delta = cfs_rq->h_nr_running;
idle_task_delta = cfs_rq->idle_h_nr_running;
+ delayed_delta = cfs_rq->h_nr_delayed;
for_each_sched_entity(se) {
struct cfs_rq *qcfs_rq = cfs_rq_of(se);
int flags;
@@ -5965,6 +5990,7 @@ static bool throttle_cfs_rq(struct cfs_rq *cfs_rq)
qcfs_rq->h_nr_running -= task_delta;
qcfs_rq->idle_h_nr_running -= idle_task_delta;
+ qcfs_rq->h_nr_delayed -= delayed_delta;
if (qcfs_rq->load.weight) {
/* Avoid re-evaluating load for this entity: */
@@ -5987,6 +6013,7 @@ static bool throttle_cfs_rq(struct cfs_rq *cfs_rq)
qcfs_rq->h_nr_running -= task_delta;
qcfs_rq->idle_h_nr_running -= idle_task_delta;
+ qcfs_rq->h_nr_delayed -= delayed_delta;
}
/* At this point se is NULL and we are at root level*/
@@ -6012,7 +6039,7 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
struct rq *rq = rq_of(cfs_rq);
struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
struct sched_entity *se;
- long task_delta, idle_task_delta;
+ long task_delta, idle_task_delta, delayed_delta;
long rq_h_nr_running = rq->cfs.h_nr_running;
se = cfs_rq->tg->se[cpu_of(rq)];
@@ -6048,6 +6075,7 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
task_delta = cfs_rq->h_nr_running;
idle_task_delta = cfs_rq->idle_h_nr_running;
+ delayed_delta = cfs_rq->h_nr_delayed;
for_each_sched_entity(se) {
struct cfs_rq *qcfs_rq = cfs_rq_of(se);
@@ -6065,6 +6093,7 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
qcfs_rq->h_nr_running += task_delta;
qcfs_rq->idle_h_nr_running += idle_task_delta;
+ qcfs_rq->h_nr_delayed += delayed_delta;
/* end evaluation on encountering a throttled cfs_rq */
if (cfs_rq_throttled(qcfs_rq))
@@ -6082,6 +6111,7 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
qcfs_rq->h_nr_running += task_delta;
qcfs_rq->idle_h_nr_running += idle_task_delta;
+ qcfs_rq->h_nr_delayed += delayed_delta;
/* end evaluation on encountering a throttled cfs_rq */
if (cfs_rq_throttled(qcfs_rq))
@@ -6930,7 +6960,7 @@ requeue_delayed_entity(struct sched_entity *se)
}
update_load_avg(cfs_rq, se, 0);
- se->sched_delayed = 0;
+ clear_delayed(se);
}
/*
@@ -6944,6 +6974,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
struct cfs_rq *cfs_rq;
struct sched_entity *se = &p->se;
int idle_h_nr_running = task_has_idle_policy(p);
+ int h_nr_delayed = 0;
int task_new = !(flags & ENQUEUE_WAKEUP);
int rq_h_nr_running = rq->cfs.h_nr_running;
u64 slice = 0;
@@ -6970,6 +7001,9 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
if (p->in_iowait)
cpufreq_update_util(rq, SCHED_CPUFREQ_IOWAIT);
+ if (task_new)
+ h_nr_delayed = !!se->sched_delayed;
+
for_each_sched_entity(se) {
if (se->on_rq) {
if (se->sched_delayed)
@@ -6992,6 +7026,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
cfs_rq->h_nr_running++;
cfs_rq->idle_h_nr_running += idle_h_nr_running;
+ cfs_rq->h_nr_delayed += h_nr_delayed;
if (cfs_rq_is_idle(cfs_rq))
idle_h_nr_running = 1;
@@ -7015,6 +7050,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
cfs_rq->h_nr_running++;
cfs_rq->idle_h_nr_running += idle_h_nr_running;
+ cfs_rq->h_nr_delayed += h_nr_delayed;
if (cfs_rq_is_idle(cfs_rq))
idle_h_nr_running = 1;
@@ -7077,6 +7113,7 @@ static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags)
struct task_struct *p = NULL;
int idle_h_nr_running = 0;
int h_nr_running = 0;
+ int h_nr_delayed = 0;
struct cfs_rq *cfs_rq;
u64 slice = 0;
@@ -7084,6 +7121,8 @@ static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags)
p = task_of(se);
h_nr_running = 1;
idle_h_nr_running = task_has_idle_policy(p);
+ if (!task_sleep && !task_delayed)
+ h_nr_delayed = !!se->sched_delayed;
} else {
cfs_rq = group_cfs_rq(se);
slice = cfs_rq_min_slice(cfs_rq);
@@ -7101,6 +7140,7 @@ static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags)
cfs_rq->h_nr_running -= h_nr_running;
cfs_rq->idle_h_nr_running -= idle_h_nr_running;
+ cfs_rq->h_nr_delayed -= h_nr_delayed;
if (cfs_rq_is_idle(cfs_rq))
idle_h_nr_running = h_nr_running;
@@ -7139,6 +7179,7 @@ static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags)
cfs_rq->h_nr_running -= h_nr_running;
cfs_rq->idle_h_nr_running -= idle_h_nr_running;
+ cfs_rq->h_nr_delayed -= h_nr_delayed;
if (cfs_rq_is_idle(cfs_rq))
idle_h_nr_running = h_nr_running;
diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c
index fc07382361a8..fee75cc2c47b 100644
--- a/kernel/sched/pelt.c
+++ b/kernel/sched/pelt.c
@@ -321,7 +321,7 @@ int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq)
{
if (___update_load_sum(now, &cfs_rq->avg,
scale_load_down(cfs_rq->load.weight),
- cfs_rq->h_nr_running,
+ cfs_rq->h_nr_running - cfs_rq->h_nr_delayed,
cfs_rq->curr != NULL)) {
___update_load_avg(&cfs_rq->avg, 1);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 5eb2d5b9722f..99d19c605e4f 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -649,6 +649,7 @@ struct cfs_rq {
unsigned int h_nr_running; /* SCHED_{NORMAL,BATCH,IDLE} */
unsigned int idle_nr_running; /* SCHED_IDLE */
unsigned int idle_h_nr_running; /* SCHED_IDLE */
+ unsigned int h_nr_delayed;
s64 avg_vruntime;
u64 avg_load;
@@ -898,8 +899,11 @@ struct dl_rq {
static inline void se_update_runnable(struct sched_entity *se)
{
- if (!entity_is_task(se))
- se->runnable_weight = se->my_q->h_nr_running;
+ if (!entity_is_task(se)) {
+ struct cfs_rq *cfs_rq = se->my_q;
+
+ se->runnable_weight = cfs_rq->h_nr_running - cfs_rq->h_nr_delayed;
+ }
}
static inline long se_runnable(struct sched_entity *se)
--
2.43.0
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