From 214c1b7f13954559cf09d5d04b934bf32ba4d618 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 11:58:52 +0100
Subject: sched/balancing: Switch the 'DEFINE_SPINLOCK(balancing)' spinlock
 into an 'atomic_t sched_balance_running' flag

The 'balancing' spinlock added in:

  08c183f31bdb ("[PATCH] sched: add option to serialize load balancing")

... is taken when the SD_SERIALIZE flag is set in a domain, but in reality it
is a glorified global atomic flag serializing the load-balancing of
those domains.

It doesn't have any explicit locking semantics per se: we just
spin_trylock() it.

Turn it into a ... global atomic flag. This makes it more
clear what is going on here, and reduces overhead and code
size a bit:

  # kernel/sched/fair.o: [x86-64 defconfig]

     text	   data	    bss	    dec	    hex	filename
    60730	   2721	    104	  63555	   f843	fair.o.before
    60718	   2721	    104	  63543	   f837	fair.o.after

Also document the flag a bit.

No change in functionality intended.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308105901.1096078-2-mingo@kernel.org
---
 kernel/sched/fair.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 6a16129f9a5c..2ef89b36aed1 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -11633,7 +11633,20 @@ out_unlock:
 	return 0;
 }
 
-static DEFINE_SPINLOCK(balancing);
+/*
+ * This flag serializes load-balancing passes over large domains
+ * (above the NODE topology level) - only one load-balancing instance
+ * may run at a time, to reduce overhead on very large systems with
+ * lots of CPUs and large NUMA distances.
+ *
+ * - Note that load-balancing passes triggered while another one
+ *   is executing are skipped and not re-tried.
+ *
+ * - Also note that this does not serialize rebalance_domains()
+ *   execution, as non-SD_SERIALIZE domains will still be
+ *   load-balanced in parallel.
+ */
+static atomic_t sched_balance_running = ATOMIC_INIT(0);
 
 /*
  * Scale the max load_balance interval with the number of CPUs in the system.
@@ -11711,7 +11724,7 @@ static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle)
 
 		need_serialize = sd->flags & SD_SERIALIZE;
 		if (need_serialize) {
-			if (!spin_trylock(&balancing))
+			if (atomic_cmpxchg_acquire(&sched_balance_running, 0, 1))
 				goto out;
 		}
 
@@ -11729,7 +11742,7 @@ static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle)
 			interval = get_sd_balance_interval(sd, busy);
 		}
 		if (need_serialize)
-			spin_unlock(&balancing);
+			atomic_set_release(&sched_balance_running, 0);
 out:
 		if (time_after(next_balance, sd->last_balance + interval)) {
 			next_balance = sd->last_balance + interval;
-- 
cgit v1.2.3


From 02a61f325a8e62a7c76479c5f2f7ddcba16877e8 Mon Sep 17 00:00:00 2001
From: Shrikanth Hegde <sshegde@linux.ibm.com>
Date: Fri, 8 Mar 2024 11:58:53 +0100
Subject: sched/balancing: Remove reliance on 'enum cpu_idle_type' ordering
 when iterating [CPU_MAX_IDLE_TYPES] arrays in show_schedstat()

show_schedstat() output breaks and doesn't print all entries
if the ordering of the definitions in 'enum cpu_idle_type' is changed,
because show_schedstat() assumes that 'CPU_IDLE' is 0.

Fix it before we change the definition order & values.

[ mingo: Added changelog. ]

Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20240308105901.1096078-3-mingo@kernel.org
---
 kernel/sched/stats.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c
index 857f837f52cb..85277953cc72 100644
--- a/kernel/sched/stats.c
+++ b/kernel/sched/stats.c
@@ -150,8 +150,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
 
 			seq_printf(seq, "domain%d %*pb", dcount++,
 				   cpumask_pr_args(sched_domain_span(sd)));
-			for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
-					itype++) {
+			for (itype = 0; itype < CPU_MAX_IDLE_TYPES; itype++) {
 				seq_printf(seq, " %u %u %u %u %u %u %u %u",
 				    sd->lb_count[itype],
 				    sd->lb_balanced[itype],
-- 
cgit v1.2.3


From 38d707c54df4ca58cd9ceae2ddcbd6f606b99e9f Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 11:58:54 +0100
Subject: sched/balancing: Change 'enum cpu_idle_type' to have more natural
 definitions

The cpu_idle_type enum has the confusingly inverted property
that 'not idle' is 1, and 'idle' is '0'.

This resulted in a number of unnecessary complications in the code.

Reverse the order, remove the CPU_NOT_IDLE type, and convert
all code to a natural boolean form.

It's much more readable:

  -       enum cpu_idle_type idle = this_rq->idle_balance ?
  -                                               CPU_IDLE : CPU_NOT_IDLE;
  -
  +       enum cpu_idle_type idle = this_rq->idle_balance;

  --------------------------------

  -       if (env->idle == CPU_NOT_IDLE || !busiest->sum_nr_running)
  +       if (!env->idle || !busiest->sum_nr_running)

  --------------------------------

And gets rid of the double negation in these usages:

  -               if (env->idle != CPU_NOT_IDLE && env->src_rq->nr_running <= 1)
  +               if (env->idle && env->src_rq->nr_running <= 1)

Furthermore, this makes code much more obvious where there's
differentiation between CPU_IDLE and CPU_NEWLY_IDLE.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Cc: "Gautham R. Shenoy" <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/20240308105901.1096078-4-mingo@kernel.org
---
 kernel/sched/fair.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 2ef89b36aed1..3a510cf1fb00 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9070,7 +9070,7 @@ static int detach_tasks(struct lb_env *env)
 		 * We don't want to steal all, otherwise we may be treated likewise,
 		 * which could at worst lead to a livelock crash.
 		 */
-		if (env->idle != CPU_NOT_IDLE && env->src_rq->nr_running <= 1)
+		if (env->idle && env->src_rq->nr_running <= 1)
 			break;
 
 		env->loop++;
@@ -9803,7 +9803,7 @@ static inline bool smt_vs_nonsmt_groups(struct sched_group *sg1,
 static inline bool smt_balance(struct lb_env *env, struct sg_lb_stats *sgs,
 			       struct sched_group *group)
 {
-	if (env->idle == CPU_NOT_IDLE)
+	if (!env->idle)
 		return false;
 
 	/*
@@ -9827,7 +9827,7 @@ static inline long sibling_imbalance(struct lb_env *env,
 	int ncores_busiest, ncores_local;
 	long imbalance;
 
-	if (env->idle == CPU_NOT_IDLE || !busiest->sum_nr_running)
+	if (!env->idle || !busiest->sum_nr_running)
 		return 0;
 
 	ncores_busiest = sds->busiest->cores;
@@ -9927,8 +9927,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
 				sgs->group_misfit_task_load = rq->misfit_task_load;
 				*sg_status |= SG_OVERLOAD;
 			}
-		} else if ((env->idle != CPU_NOT_IDLE) &&
-			   sched_reduced_capacity(rq, env->sd)) {
+		} else if (env->idle && sched_reduced_capacity(rq, env->sd)) {
 			/* Check for a task running on a CPU with reduced capacity */
 			if (sgs->group_misfit_task_load < load)
 				sgs->group_misfit_task_load = load;
@@ -9940,7 +9939,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
 	sgs->group_weight = group->group_weight;
 
 	/* Check if dst CPU is idle and preferred to this group */
-	if (!local_group && env->idle != CPU_NOT_IDLE && sgs->sum_h_nr_running &&
+	if (!local_group && env->idle && sgs->sum_h_nr_running &&
 	    sched_group_asym(env, sgs, group))
 		sgs->group_asym_packing = 1;
 
@@ -10698,7 +10697,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
 			 * waiting task in this overloaded busiest group. Let's
 			 * try to pull it.
 			 */
-			if (env->idle != CPU_NOT_IDLE && env->imbalance == 0) {
+			if (env->idle && env->imbalance == 0) {
 				env->migration_type = migrate_task;
 				env->imbalance = 1;
 			}
@@ -10913,7 +10912,7 @@ static struct sched_group *find_busiest_group(struct lb_env *env)
 		goto force_balance;
 
 	if (busiest->group_type != group_overloaded) {
-		if (env->idle == CPU_NOT_IDLE) {
+		if (!env->idle) {
 			/*
 			 * If the busiest group is not overloaded (and as a
 			 * result the local one too) but this CPU is already
@@ -11121,7 +11120,7 @@ asym_active_balance(struct lb_env *env)
 	 * the lower priority @env::dst_cpu help it. Do not follow
 	 * CPU priority.
 	 */
-	return env->idle != CPU_NOT_IDLE && sched_use_asym_prio(env->sd, env->dst_cpu) &&
+	return env->idle && sched_use_asym_prio(env->sd, env->dst_cpu) &&
 	       (sched_asym_prefer(env->dst_cpu, env->src_cpu) ||
 		!sched_use_asym_prio(env->sd, env->src_cpu));
 }
@@ -11159,7 +11158,7 @@ static int need_active_balance(struct lb_env *env)
 	 * because of other sched_class or IRQs if more capacity stays
 	 * available on dst_cpu.
 	 */
-	if ((env->idle != CPU_NOT_IDLE) &&
+	if (env->idle &&
 	    (env->src_rq->cfs.h_nr_running == 1)) {
 		if ((check_cpu_capacity(env->src_rq, sd)) &&
 		    (capacity_of(env->src_cpu)*sd->imbalance_pct < capacity_of(env->dst_cpu)*100))
@@ -11735,8 +11734,8 @@ static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle)
 				 * env->dst_cpu, so we can't know our idle
 				 * state even if we migrated tasks. Update it.
 				 */
-				idle = idle_cpu(cpu) ? CPU_IDLE : CPU_NOT_IDLE;
-				busy = idle != CPU_IDLE && !sched_idle_cpu(cpu);
+				idle = idle_cpu(cpu);
+				busy = !idle && !sched_idle_cpu(cpu);
 			}
 			sd->last_balance = jiffies;
 			interval = get_sd_balance_interval(sd, busy);
@@ -12416,9 +12415,7 @@ out:
 static __latent_entropy void run_rebalance_domains(struct softirq_action *h)
 {
 	struct rq *this_rq = this_rq();
-	enum cpu_idle_type idle = this_rq->idle_balance ?
-						CPU_IDLE : CPU_NOT_IDLE;
-
+	enum cpu_idle_type idle = this_rq->idle_balance;
 	/*
 	 * If this CPU has a pending nohz_balance_kick, then do the
 	 * balancing on behalf of the other idle CPUs whose ticks are
-- 
cgit v1.2.3


From 11b0bfa5d463b17cac5bf6b94fea4921713530c3 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 11:58:55 +0100
Subject: sched/debug: Increase SCHEDSTAT_VERSION to 16

We changed the order of definitions within 'enum cpu_idle_type',
which changed the order of [CPU_MAX_IDLE_TYPES] columns in
show_schedstat().

Suggested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "Gautham R. Shenoy" <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/20240308105901.1096078-5-mingo@kernel.org
---
 kernel/sched/stats.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c
index 85277953cc72..78e48f5426ee 100644
--- a/kernel/sched/stats.c
+++ b/kernel/sched/stats.c
@@ -113,7 +113,7 @@ void __update_stats_enqueue_sleeper(struct rq *rq, struct task_struct *p,
  * Bump this up when changing the output format or the meaning of an existing
  * format, so that tools can adapt (or abort)
  */
-#define SCHEDSTAT_VERSION 15
+#define SCHEDSTAT_VERSION 16
 
 static int show_schedstat(struct seq_file *seq, void *v)
 {
-- 
cgit v1.2.3


From be8858dba9a2c3aec454a6b382671101fd0dc3b7 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 11:58:57 +0100
Subject: sched/balancing: Change comment formatting to not overlap Git
 conflict marker lines

So the scheduler has two such comment blocks, with '=' used as a double underline:

        /*
         * VRUNTIME
         * ========
         *

'========' also happens to be a Git conflict marker, throwing off a simple
search in an editor for this pattern.

Change them to '-------' type of underline instead - it looks just as good.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20240308105901.1096078-7-mingo@kernel.org
---
 kernel/sched/fair.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 3a510cf1fb00..84d4791cf628 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3679,7 +3679,7 @@ static void reweight_eevdf(struct cfs_rq *cfs_rq, struct sched_entity *se,
 
 	/*
 	 * VRUNTIME
-	 * ========
+	 * --------
 	 *
 	 * COROLLARY #1: The virtual runtime of the entity needs to be
 	 * adjusted if re-weight at !0-lag point.
@@ -3762,7 +3762,7 @@ static void reweight_eevdf(struct cfs_rq *cfs_rq, struct sched_entity *se,
 
 	/*
 	 * DEADLINE
-	 * ========
+	 * --------
 	 *
 	 * When the weight changes, the virtual time slope changes and
 	 * we should adjust the relative virtual deadline accordingly.
-- 
cgit v1.2.3


From 3a5fe9305719c680ccf63216781a4d4068c8e3f3 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 11:58:58 +0100
Subject: sched/balancing: Fix comments (trying to) refer to NOHZ_BALANCE_KICK

Fix two typos:

 - There's no such thing as 'nohz_balancing_kick', the
   flag is named 'BALANCE' and is capitalized:  NOHZ_BALANCE_KICK.

 - Likewise there's no such thing as a 'pending nohz_balance_kick'
   either, the NOHZ_BALANCE_KICK flag is all upper-case.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20240308105901.1096078-8-mingo@kernel.org
---
 kernel/sched/fair.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 84d4791cf628..f3c03c6db3c8 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -12409,15 +12409,16 @@ out:
 }
 
 /*
- * run_rebalance_domains is triggered when needed from the scheduler tick.
- * Also triggered for nohz idle balancing (with nohz_balancing_kick set).
+ * This softirq may be triggered from the scheduler tick, or by
+ * any of the flags in NOHZ_KICK_MASK: NOHZ_BALANCE_KICK,
+ * NOHZ_STATS_KICK or NOHZ_NEXT_KICK.
  */
 static __latent_entropy void run_rebalance_domains(struct softirq_action *h)
 {
 	struct rq *this_rq = this_rq();
 	enum cpu_idle_type idle = this_rq->idle_balance;
 	/*
-	 * If this CPU has a pending nohz_balance_kick, then do the
+	 * If this CPU has a pending NOHZ_BALANCE_KICK, then do the
 	 * balancing on behalf of the other idle CPUs whose ticks are
 	 * stopped. Do nohz_idle_balance *before* rebalance_domains to
 	 * give the idle CPUs a chance to load balance. Else we may
-- 
cgit v1.2.3


From 3dc6f6c8efe2d9148865664fffbe9dd89fb0d157 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 11:58:59 +0100
Subject: sched/balancing: Update run_rebalance_domains() comments

The first sentence of the comment explaining run_rebalance_domains()
is historic and not true anymore:

    * run_rebalance_domains is triggered when needed from the scheduler tick.

... contradicted/modified by the second sentence:

    * Also triggered for NOHZ idle balancing (with NOHZ_BALANCE_KICK set).

Avoid that kind of confusion straight away and explain from what
places sched_balance_softirq() is triggered.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/20240308105901.1096078-9-mingo@kernel.org
---
 kernel/sched/fair.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f3c03c6db3c8..b567c0790f44 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -12409,9 +12409,12 @@ out:
 }
 
 /*
- * This softirq may be triggered from the scheduler tick, or by
- * any of the flags in NOHZ_KICK_MASK: NOHZ_BALANCE_KICK,
- * NOHZ_STATS_KICK or NOHZ_NEXT_KICK.
+ * This softirq handler is triggered via SCHED_SOFTIRQ from two places:
+ *
+ * - directly from the local scheduler_tick() for periodic load balancing
+ *
+ * - indirectly from a remote scheduler_tick() for NOHZ idle balancing
+ *   through the SMP cross-call nohz_csd_func()
  */
 static __latent_entropy void run_rebalance_domains(struct softirq_action *h)
 {
-- 
cgit v1.2.3


From e492e1b0e0721f3929ef9d9708d029144b396dd7 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 11:59:00 +0100
Subject: sched/balancing: Vertically align the comments of 'struct
 sg_lb_stats' and 'struct sd_lb_stats'

Make them easier to read.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20240308105901.1096078-10-mingo@kernel.org
---
 kernel/sched/fair.c | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index b567c0790f44..40b98e43d794 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9436,19 +9436,19 @@ static void update_blocked_averages(int cpu)
  * sg_lb_stats - stats of a sched_group required for load_balancing
  */
 struct sg_lb_stats {
-	unsigned long avg_load; /*Avg load across the CPUs of the group */
-	unsigned long group_load; /* Total load over the CPUs of the group */
+	unsigned long avg_load;			/* Avg load across the CPUs of the group */
+	unsigned long group_load;		/* Total load over the CPUs of the group */
 	unsigned long group_capacity;
-	unsigned long group_util; /* Total utilization over the CPUs of the group */
-	unsigned long group_runnable; /* Total runnable time over the CPUs of the group */
-	unsigned int sum_nr_running; /* Nr of tasks running in the group */
-	unsigned int sum_h_nr_running; /* Nr of CFS tasks running in the group */
+	unsigned long group_util;		/* Total utilization over the CPUs of the group */
+	unsigned long group_runnable;		/* Total runnable time over the CPUs of the group */
+	unsigned int sum_nr_running;		/* Nr of tasks running in the group */
+	unsigned int sum_h_nr_running;		/* Nr of CFS tasks running in the group */
 	unsigned int idle_cpus;
 	unsigned int group_weight;
 	enum group_type group_type;
-	unsigned int group_asym_packing; /* Tasks should be moved to preferred CPU */
-	unsigned int group_smt_balance;  /* Task on busy SMT be moved */
-	unsigned long group_misfit_task_load; /* A CPU has a task too big for its capacity */
+	unsigned int group_asym_packing;	/* Tasks should be moved to preferred CPU */
+	unsigned int group_smt_balance;		/* Task on busy SMT be moved */
+	unsigned long group_misfit_task_load;	/* A CPU has a task too big for its capacity */
 #ifdef CONFIG_NUMA_BALANCING
 	unsigned int nr_numa_running;
 	unsigned int nr_preferred_running;
@@ -9460,15 +9460,15 @@ struct sg_lb_stats {
  *		 during load balancing.
  */
 struct sd_lb_stats {
-	struct sched_group *busiest;	/* Busiest group in this sd */
-	struct sched_group *local;	/* Local group in this sd */
-	unsigned long total_load;	/* Total load of all groups in sd */
-	unsigned long total_capacity;	/* Total capacity of all groups in sd */
-	unsigned long avg_load;	/* Average load across all groups in sd */
-	unsigned int prefer_sibling; /* tasks should go to sibling first */
-
-	struct sg_lb_stats busiest_stat;/* Statistics of the busiest group */
-	struct sg_lb_stats local_stat;	/* Statistics of the local group */
+	struct sched_group *busiest;		/* Busiest group in this sd */
+	struct sched_group *local;		/* Local group in this sd */
+	unsigned long total_load;		/* Total load of all groups in sd */
+	unsigned long total_capacity;		/* Total capacity of all groups in sd */
+	unsigned long avg_load;			/* Average load across all groups in sd */
+	unsigned int prefer_sibling;		/* tasks should go to sibling first */
+
+	struct sg_lb_stats busiest_stat;	/* Statistics of the busiest group */
+	struct sg_lb_stats local_stat;		/* Statistics of the local group */
 };
 
 static inline void init_sd_lb_stats(struct sd_lb_stats *sds)
-- 
cgit v1.2.3


From 33928ed8bde066316dc3cb6ccf7f74400073652f Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 11:59:01 +0100
Subject: sched/balancing: Update comments in 'struct sg_lb_stats' and 'struct
 sd_lb_stats'

- Align for readability
- Capitalize consistently

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20240308105901.1096078-11-mingo@kernel.org
---
 kernel/sched/fair.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 40b98e43d794..116a640534b9 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9433,17 +9433,17 @@ static void update_blocked_averages(int cpu)
 /********** Helpers for find_busiest_group ************************/
 
 /*
- * sg_lb_stats - stats of a sched_group required for load_balancing
+ * sg_lb_stats - stats of a sched_group required for load-balancing:
  */
 struct sg_lb_stats {
-	unsigned long avg_load;			/* Avg load across the CPUs of the group */
-	unsigned long group_load;		/* Total load over the CPUs of the group */
-	unsigned long group_capacity;
-	unsigned long group_util;		/* Total utilization over the CPUs of the group */
+	unsigned long avg_load;			/* Avg load            over the CPUs of the group */
+	unsigned long group_load;		/* Total load          over the CPUs of the group */
+	unsigned long group_capacity;		/* Capacity            over the CPUs of the group */
+	unsigned long group_util;		/* Total utilization   over the CPUs of the group */
 	unsigned long group_runnable;		/* Total runnable time over the CPUs of the group */
-	unsigned int sum_nr_running;		/* Nr of tasks running in the group */
+	unsigned int sum_nr_running;		/* Nr of all tasks running in the group */
 	unsigned int sum_h_nr_running;		/* Nr of CFS tasks running in the group */
-	unsigned int idle_cpus;
+	unsigned int idle_cpus;                 /* Nr of idle CPUs         in the group */
 	unsigned int group_weight;
 	enum group_type group_type;
 	unsigned int group_asym_packing;	/* Tasks should be moved to preferred CPU */
@@ -9456,8 +9456,7 @@ struct sg_lb_stats {
 };
 
 /*
- * sd_lb_stats - Structure to store the statistics of a sched_domain
- *		 during load balancing.
+ * sd_lb_stats - stats of a sched_domain required for load-balancing:
  */
 struct sd_lb_stats {
 	struct sched_group *busiest;		/* Busiest group in this sd */
@@ -9465,7 +9464,7 @@ struct sd_lb_stats {
 	unsigned long total_load;		/* Total load of all groups in sd */
 	unsigned long total_capacity;		/* Total capacity of all groups in sd */
 	unsigned long avg_load;			/* Average load across all groups in sd */
-	unsigned int prefer_sibling;		/* tasks should go to sibling first */
+	unsigned int prefer_sibling;		/* Tasks should go to sibling first */
 
 	struct sg_lb_stats busiest_stat;	/* Statistics of the busiest group */
 	struct sg_lb_stats local_stat;		/* Statistics of the local group */
-- 
cgit v1.2.3


From 70a27d6d1b19392a23bb4a41de7788fbc539f18d Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 12:18:07 +0100
Subject: sched/balancing: Rename run_rebalance_domains() =>
 sched_balance_softirq()

run_rebalance_domains() is a misnomer, as it doesn't only
run rebalance_domains(), but since the introduction of the
NOHZ code it also runs nohz_idle_balance().

Rename it to sched_balance_softirq(), reflecting its more
generic purpose and that it's a softirq handler.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-2-mingo@kernel.org
---
 kernel/sched/fair.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 116a640534b9..953f39deb68e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -12415,7 +12415,7 @@ out:
  * - indirectly from a remote scheduler_tick() for NOHZ idle balancing
  *   through the SMP cross-call nohz_csd_func()
  */
-static __latent_entropy void run_rebalance_domains(struct softirq_action *h)
+static __latent_entropy void sched_balance_softirq(struct softirq_action *h)
 {
 	struct rq *this_rq = this_rq();
 	enum cpu_idle_type idle = this_rq->idle_balance;
@@ -13216,7 +13216,7 @@ __init void init_sched_fair_class(void)
 #endif
 	}
 
-	open_softirq(SCHED_SOFTIRQ, run_rebalance_domains);
+	open_softirq(SCHED_SOFTIRQ, sched_balance_softirq);
 
 #ifdef CONFIG_NO_HZ_COMMON
 	nohz.next_balance = jiffies;
-- 
cgit v1.2.3


From 86dd6c04ef9f213e14d60c9f64bce1cc019f816e Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 12:18:08 +0100
Subject: sched/balancing: Rename scheduler_tick() => sched_tick()

- Standardize on prefixing scheduler-internal functions defined
  in <linux/sched.h> with sched_*() prefix. scheduler_tick() was
  the only function using the scheduler_ prefix. Harmonize it.

- The other reason to rename it is the NOHZ scheduler tick
  handling functions are already named sched_tick_*().
  Make the 'git grep sched_tick' more meaningful.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-3-mingo@kernel.org
---
 kernel/sched/core.c    | 4 ++--
 kernel/sched/loadavg.c | 2 +-
 kernel/time/timer.c    | 2 +-
 kernel/workqueue.c     | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d44efa0d0611..71b7a08a6502 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5662,7 +5662,7 @@ static inline u64 cpu_resched_latency(struct rq *rq) { return 0; }
  * This function gets called by the timer code, with HZ frequency.
  * We call it with interrupts disabled.
  */
-void scheduler_tick(void)
+void sched_tick(void)
 {
 	int cpu = smp_processor_id();
 	struct rq *rq = cpu_rq(cpu);
@@ -6585,7 +6585,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
  *      paths. For example, see arch/x86/entry_64.S.
  *
  *      To drive preemption between tasks, the scheduler sets the flag in timer
- *      interrupt handler scheduler_tick().
+ *      interrupt handler sched_tick().
  *
  *   3. Wakeups don't really cause entry into schedule(). They add a
  *      task to the run-queue and that's it.
diff --git a/kernel/sched/loadavg.c b/kernel/sched/loadavg.c
index 52c8f8226b0d..ca9da66cc894 100644
--- a/kernel/sched/loadavg.c
+++ b/kernel/sched/loadavg.c
@@ -379,7 +379,7 @@ void calc_global_load(void)
 }
 
 /*
- * Called from scheduler_tick() to periodically update this CPU's
+ * Called from sched_tick() to periodically update this CPU's
  * active count.
  */
 void calc_global_load_tick(struct rq *this_rq)
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index e69e75d3858c..ff49ddcc9800 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -2478,7 +2478,7 @@ void update_process_times(int user_tick)
 	if (in_irq())
 		irq_work_tick();
 #endif
-	scheduler_tick();
+	sched_tick();
 	if (IS_ENABLED(CONFIG_POSIX_TIMERS))
 		run_posix_cpu_timers();
 }
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index bf2bdac46843..8fbb0ec39079 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1464,7 +1464,7 @@ void wq_worker_sleeping(struct task_struct *task)
  * wq_worker_tick - a scheduler tick occurred while a kworker is running
  * @task: task currently running
  *
- * Called from scheduler_tick(). We're in the IRQ context and the current
+ * Called from sched_tick(). We're in the IRQ context and the current
  * worker's fields which follow the 'K' locking rule can be accessed safely.
  */
 void wq_worker_tick(struct task_struct *task)
-- 
cgit v1.2.3


From 983be0628c061989b6cc175d2f5e429b40699fbb Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 12:18:09 +0100
Subject: sched/balancing: Rename trigger_load_balance() =>
 sched_balance_trigger()

Standardize scheduler load-balancing function names on the
sched_balance_() prefix.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-4-mingo@kernel.org
---
 kernel/sched/core.c  | 2 +-
 kernel/sched/fair.c  | 2 +-
 kernel/sched/sched.h | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 71b7a08a6502..929fce69f555 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5700,7 +5700,7 @@ void sched_tick(void)
 
 #ifdef CONFIG_SMP
 	rq->idle_balance = idle_cpu(cpu);
-	trigger_load_balance(rq);
+	sched_balance_trigger(rq);
 #endif
 }
 
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 953f39deb68e..e377b675920a 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -12438,7 +12438,7 @@ static __latent_entropy void sched_balance_softirq(struct softirq_action *h)
 /*
  * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing.
  */
-void trigger_load_balance(struct rq *rq)
+void sched_balance_trigger(struct rq *rq)
 {
 	/*
 	 * Don't need to rebalance while attached to NULL domain or
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index d2242679239e..5b0ddb0e6017 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -2397,7 +2397,7 @@ extern struct task_struct *pick_next_task_idle(struct rq *rq);
 
 extern void update_group_capacity(struct sched_domain *sd, int cpu);
 
-extern void trigger_load_balance(struct rq *rq);
+extern void sched_balance_trigger(struct rq *rq);
 
 extern void set_cpus_allowed_common(struct task_struct *p, struct affinity_context *ctx);
 
-- 
cgit v1.2.3


From 14ff4dbd34f46cc6b6105f549983321241ccbba9 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 12:18:10 +0100
Subject: sched/balancing: Rename rebalance_domains() =>
 sched_balance_domains()

Standardize scheduler load-balancing function names on the
sched_balance_() prefix.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-5-mingo@kernel.org
---
 kernel/sched/fair.c  | 8 ++++----
 kernel/sched/sched.h | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e377b675920a..330788b0c617 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -11685,7 +11685,7 @@ static inline bool update_newidle_cost(struct sched_domain *sd, u64 cost)
  *
  * Balancing parameters are set up in init_sched_domains.
  */
-static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle)
+static void sched_balance_domains(struct rq *rq, enum cpu_idle_type idle)
 {
 	int continue_balancing = 1;
 	int cpu = rq->cpu;
@@ -12161,7 +12161,7 @@ static void _nohz_idle_balance(struct rq *this_rq, unsigned int flags)
 			rq_unlock_irqrestore(rq, &rf);
 
 			if (flags & NOHZ_BALANCE_KICK)
-				rebalance_domains(rq, CPU_IDLE);
+				sched_balance_domains(rq, CPU_IDLE);
 		}
 
 		if (time_after(next_balance, rq->next_balance)) {
@@ -12422,7 +12422,7 @@ static __latent_entropy void sched_balance_softirq(struct softirq_action *h)
 	/*
 	 * If this CPU has a pending NOHZ_BALANCE_KICK, then do the
 	 * balancing on behalf of the other idle CPUs whose ticks are
-	 * stopped. Do nohz_idle_balance *before* rebalance_domains to
+	 * stopped. Do nohz_idle_balance *before* sched_balance_domains to
 	 * give the idle CPUs a chance to load balance. Else we may
 	 * load balance only within the local sched_domain hierarchy
 	 * and abort nohz_idle_balance altogether if we pull some load.
@@ -12432,7 +12432,7 @@ static __latent_entropy void sched_balance_softirq(struct softirq_action *h)
 
 	/* normal load balance */
 	update_blocked_averages(this_rq->cpu);
-	rebalance_domains(this_rq, idle);
+	sched_balance_domains(this_rq, idle);
 }
 
 /*
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 5b0ddb0e6017..41024c1c49b4 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -2904,7 +2904,7 @@ extern void cfs_bandwidth_usage_dec(void);
 #define NOHZ_NEWILB_KICK_BIT	2
 #define NOHZ_NEXT_KICK_BIT	3
 
-/* Run rebalance_domains() */
+/* Run sched_balance_domains() */
 #define NOHZ_BALANCE_KICK	BIT(NOHZ_BALANCE_KICK_BIT)
 /* Update blocked load */
 #define NOHZ_STATS_KICK		BIT(NOHZ_STATS_KICK_BIT)
-- 
cgit v1.2.3


From 4c3e509ea9f249458e8692f8298cceac73105948 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 12:18:11 +0100
Subject: sched/balancing: Rename load_balance() => sched_balance_rq()

Standardize scheduler load-balancing function names on the
sched_balance_() prefix.

Also load_balance() has become somewhat of a misnomer: historically
it was the first and primary load-balancing function that was called,
but with the introduction of sched domains, it's become a lower
layer function that balances runqueues.

Rename it to sched_balance_rq() accordingly.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-6-mingo@kernel.org
---
 kernel/sched/fair.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 330788b0c617..0d2753c50be9 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6866,7 +6866,7 @@ dequeue_throttle:
 
 #ifdef CONFIG_SMP
 
-/* Working cpumask for: load_balance, load_balance_newidle. */
+/* Working cpumask for: sched_balance_rq, load_balance_newidle. */
 static DEFINE_PER_CPU(cpumask_var_t, load_balance_mask);
 static DEFINE_PER_CPU(cpumask_var_t, select_rq_mask);
 static DEFINE_PER_CPU(cpumask_var_t, should_we_balance_tmpmask);
@@ -11242,7 +11242,7 @@ static int should_we_balance(struct lb_env *env)
  * Check this_cpu to ensure it is balanced within domain. Attempt to move
  * tasks if there is an imbalance.
  */
-static int load_balance(int this_cpu, struct rq *this_rq,
+static int sched_balance_rq(int this_cpu, struct rq *this_rq,
 			struct sched_domain *sd, enum cpu_idle_type idle,
 			int *continue_balancing)
 {
@@ -11647,7 +11647,7 @@ out_unlock:
 static atomic_t sched_balance_running = ATOMIC_INIT(0);
 
 /*
- * Scale the max load_balance interval with the number of CPUs in the system.
+ * Scale the max sched_balance_rq interval with the number of CPUs in the system.
  * This trades load-balance latency on larger machines for less cross talk.
  */
 void update_max_interval(void)
@@ -11727,7 +11727,7 @@ static void sched_balance_domains(struct rq *rq, enum cpu_idle_type idle)
 		}
 
 		if (time_after_eq(jiffies, sd->last_balance + interval)) {
-			if (load_balance(cpu, rq, sd, idle, &continue_balancing)) {
+			if (sched_balance_rq(cpu, rq, sd, idle, &continue_balancing)) {
 				/*
 				 * The LBF_DST_PINNED logic could have changed
 				 * env->dst_cpu, so we can't know our idle
@@ -12353,7 +12353,7 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
 
 		if (sd->flags & SD_BALANCE_NEWIDLE) {
 
-			pulled_task = load_balance(this_cpu, this_rq,
+			pulled_task = sched_balance_rq(this_cpu, this_rq,
 						   sd, CPU_NEWLY_IDLE,
 						   &continue_balancing);
 
-- 
cgit v1.2.3


From f1cd2e2e79d283e315356bd403c7f928e994f057 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Mon, 23 Oct 2023 13:04:12 +0200
Subject: sched/balancing: Rename find_busiest_queue() =>
 sched_balance_find_src_rq()

The find_busiest_queue() naming has two small quirks:

 - Scheduler functions that deal with runqueues usually have a rq_ prefix
   or _rq postfix, but this function has neither.

 - Plus the 'busiest' qualifier to this function was historically
   correct, but has become somewhat of a misnomer: in quite a few
   cases we will not pick the busiest runqueue - but the best
   (possible) runqueue we can balance tasks from. So name it a
   bit more neutrally, similar to the 'src/dst' nomenclature
   we are already using when moving tasks between runqueues.

To fix both quirks, and to standardize scheduler load-balancing
function names on the sched_balance_() prefix, rename the
function to sched_balance_find_src_rq().

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-7-mingo@kernel.org
---
 kernel/sched/fair.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0d2753c50be9..1cd9a18b35e0 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -10959,9 +10959,9 @@ out_balanced:
 }
 
 /*
- * find_busiest_queue - find the busiest runqueue among the CPUs in the group.
+ * sched_balance_find_src_rq - find the busiest runqueue among the CPUs in the group.
  */
-static struct rq *find_busiest_queue(struct lb_env *env,
+static struct rq *sched_balance_find_src_rq(struct lb_env *env,
 				     struct sched_group *group)
 {
 	struct rq *busiest = NULL, *rq;
@@ -11280,7 +11280,7 @@ redo:
 		goto out_balanced;
 	}
 
-	busiest = find_busiest_queue(&env, group);
+	busiest = sched_balance_find_src_rq(&env, group);
 	if (!busiest) {
 		schedstat_inc(sd->lb_nobusyq[idle]);
 		goto out_balanced;
-- 
cgit v1.2.3


From 82cf921432fc184adbbb9c1bced182564876ec5e Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 12:18:14 +0100
Subject: sched/balancing: Rename find_busiest_group() =>
 sched_balance_find_src_group()

Make two naming changes:

1)
   Standardize scheduler load-balancing function names on the
   sched_balance_() prefix.

2)

   Similar to find_busiest_queue(), the find_busiest_group() naming
   has become a bit of a misnomer: the 'busiest' qualifier to this
   function was historically correct but in the current code
   in quite a few cases we will not pick the 'busiest' group - but the best
   (possible) group we can balance from based on a complex set of
   constraints.

So name it a bit more neutrally, similar to the 'src/dst' nomenclature
we are already using when moving tasks between runqueues, and also
use the sched_balance_ prefix: sched_balance_find_src_group().

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-9-mingo@kernel.org
---
 kernel/sched/fair.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1cd9a18b35e0..96a81b2fa281 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9430,7 +9430,7 @@ static void update_blocked_averages(int cpu)
 	rq_unlock_irqrestore(rq, &rf);
 }
 
-/********** Helpers for find_busiest_group ************************/
+/********** Helpers for sched_balance_find_src_group ************************/
 
 /*
  * sg_lb_stats - stats of a sched_group required for load-balancing:
@@ -9637,7 +9637,7 @@ static inline int check_misfit_status(struct rq *rq, struct sched_domain *sd)
  *
  * When this is so detected; this group becomes a candidate for busiest; see
  * update_sd_pick_busiest(). And calculate_imbalance() and
- * find_busiest_group() avoid some of the usual balance conditions to allow it
+ * sched_balance_find_src_group() avoid some of the usual balance conditions to allow it
  * to create an effective group imbalance.
  *
  * This is a somewhat tricky proposition since the next run might not find the
@@ -10788,7 +10788,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
 	) / SCHED_CAPACITY_SCALE;
 }
 
-/******* find_busiest_group() helpers end here *********************/
+/******* sched_balance_find_src_group() helpers end here *********************/
 
 /*
  * Decision matrix according to the local and busiest group type:
@@ -10811,7 +10811,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
  */
 
 /**
- * find_busiest_group - Returns the busiest group within the sched_domain
+ * sched_balance_find_src_group - Returns the busiest group within the sched_domain
  * if there is an imbalance.
  * @env: The load balancing environment.
  *
@@ -10820,7 +10820,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
  *
  * Return:	- The busiest group if imbalance exists.
  */
-static struct sched_group *find_busiest_group(struct lb_env *env)
+static struct sched_group *sched_balance_find_src_group(struct lb_env *env)
 {
 	struct sg_lb_stats *local, *busiest;
 	struct sd_lb_stats sds;
@@ -11274,7 +11274,7 @@ redo:
 		goto out_balanced;
 	}
 
-	group = find_busiest_group(&env);
+	group = sched_balance_find_src_group(&env);
 	if (!group) {
 		schedstat_inc(sd->lb_nobusyg[idle]);
 		goto out_balanced;
@@ -11298,7 +11298,7 @@ redo:
 	env.flags |= LBF_ALL_PINNED;
 	if (busiest->nr_running > 1) {
 		/*
-		 * Attempt to move tasks. If find_busiest_group has found
+		 * Attempt to move tasks. If sched_balance_find_src_group has found
 		 * an imbalance but busiest->nr_running <= 1, the group is
 		 * still unbalanced. ld_moved simply stays zero, so it is
 		 * correctly treated as an imbalance.
-- 
cgit v1.2.3


From 391b7a5335c45b2bafe535cb440836ccd17515aa Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 12:18:15 +0100
Subject: sched/balancing: Rename update_blocked_averages() =>
 sched_balance_update_blocked_averages()

Standardize scheduler load-balancing function names on the
sched_balance_() prefix.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-10-mingo@kernel.org
---
 kernel/sched/fair.c | 8 ++++----
 kernel/sched/pelt.c | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 96a81b2fa281..95f7092043f3 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9411,7 +9411,7 @@ static unsigned long task_h_load(struct task_struct *p)
 }
 #endif
 
-static void update_blocked_averages(int cpu)
+static void sched_balance_update_blocked_averages(int cpu)
 {
 	bool decayed = false, done = true;
 	struct rq *rq = cpu_rq(cpu);
@@ -12079,7 +12079,7 @@ static bool update_nohz_stats(struct rq *rq)
 	if (!time_after(jiffies, READ_ONCE(rq->last_blocked_load_update_tick)))
 		return true;
 
-	update_blocked_averages(cpu);
+	sched_balance_update_blocked_averages(cpu);
 
 	return rq->has_blocked_load;
 }
@@ -12339,7 +12339,7 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
 	raw_spin_rq_unlock(this_rq);
 
 	t0 = sched_clock_cpu(this_cpu);
-	update_blocked_averages(this_cpu);
+	sched_balance_update_blocked_averages(this_cpu);
 
 	rcu_read_lock();
 	for_each_domain(this_cpu, sd) {
@@ -12431,7 +12431,7 @@ static __latent_entropy void sched_balance_softirq(struct softirq_action *h)
 		return;
 
 	/* normal load balance */
-	update_blocked_averages(this_rq->cpu);
+	sched_balance_update_blocked_averages(this_rq->cpu);
 	sched_balance_domains(this_rq, idle);
 }
 
diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c
index 63b6cf898220..f80955ecdce6 100644
--- a/kernel/sched/pelt.c
+++ b/kernel/sched/pelt.c
@@ -209,7 +209,7 @@ ___update_load_sum(u64 now, struct sched_avg *sa,
 	 * This means that weight will be 0 but not running for a sched_entity
 	 * but also for a cfs_rq if the latter becomes idle. As an example,
 	 * this happens during idle_balance() which calls
-	 * update_blocked_averages().
+	 * sched_balance_update_blocked_averages().
 	 *
 	 * Also see the comment in accumulate_sum().
 	 */
-- 
cgit v1.2.3


From 7d058285cd77cc1411c91efd1b1673530bb1bee8 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 12:18:16 +0100
Subject: sched/balancing: Rename newidle_balance() => sched_balance_newidle()

Standardize scheduler load-balancing function names on the
sched_balance_() prefix.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-11-mingo@kernel.org
---
 kernel/sched/fair.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 95f7092043f3..aa5ff0efcca8 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4816,7 +4816,7 @@ static inline unsigned long cfs_rq_load_avg(struct cfs_rq *cfs_rq)
 	return cfs_rq->avg.load_avg;
 }
 
-static int newidle_balance(struct rq *this_rq, struct rq_flags *rf);
+static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf);
 
 static inline unsigned long task_util(struct task_struct *p)
 {
@@ -5136,7 +5136,7 @@ attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
 static inline void
 detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
 
-static inline int newidle_balance(struct rq *rq, struct rq_flags *rf)
+static inline int sched_balance_newidle(struct rq *rq, struct rq_flags *rf)
 {
 	return 0;
 }
@@ -8253,7 +8253,7 @@ balance_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 	if (rq->nr_running)
 		return 1;
 
-	return newidle_balance(rq, rf) != 0;
+	return sched_balance_newidle(rq, rf) != 0;
 }
 #endif /* CONFIG_SMP */
 
@@ -8505,10 +8505,10 @@ idle:
 	if (!rf)
 		return NULL;
 
-	new_tasks = newidle_balance(rq, rf);
+	new_tasks = sched_balance_newidle(rq, rf);
 
 	/*
-	 * Because newidle_balance() releases (and re-acquires) rq->lock, it is
+	 * Because sched_balance_newidle() releases (and re-acquires) rq->lock, it is
 	 * possible for any higher priority task to appear. In that case we
 	 * must re-start the pick_next_entity() loop.
 	 */
@@ -11493,7 +11493,7 @@ out_one_pinned:
 	ld_moved = 0;
 
 	/*
-	 * newidle_balance() disregards balance intervals, so we could
+	 * sched_balance_newidle() disregards balance intervals, so we could
 	 * repeatedly reach this code, which would lead to balance_interval
 	 * skyrocketing in a short amount of time. Skip the balance_interval
 	 * increase logic to avoid that.
@@ -12277,7 +12277,7 @@ static inline void nohz_newidle_balance(struct rq *this_rq) { }
 #endif /* CONFIG_NO_HZ_COMMON */
 
 /*
- * newidle_balance is called by schedule() if this_cpu is about to become
+ * sched_balance_newidle is called by schedule() if this_cpu is about to become
  * idle. Attempts to pull tasks from other CPUs.
  *
  * Returns:
@@ -12285,7 +12285,7 @@ static inline void nohz_newidle_balance(struct rq *this_rq) { }
  *     0 - failed, no new tasks
  *   > 0 - success, new (fair) tasks present
  */
-static int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
+static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf)
 {
 	unsigned long next_balance = jiffies + HZ;
 	int this_cpu = this_rq->cpu;
-- 
cgit v1.2.3


From 646ebaf51c64c6416ca89765c20041363fc1b518 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 12:18:17 +0100
Subject: sched/balancing: Rename find_idlest_group_cpu() =>
 sched_balance_find_dst_group_cpu()

Standardize scheduler load-balancing function names on the
sched_balance_() prefix.

Also use 'dst' instead of 'idlest': while historically correct,
today it's not really true anymore that we return the 'idlest'
group or CPU, we sort by idle-exit latency and only return the
idlest CPUs from the lowest-latency set of CPUs.

The true 'idlest' CPUs often remain idle for a long time
and are never returned as long as the system is under-loaded.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-12-mingo@kernel.org
---
 kernel/sched/fair.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index aa5ff0efcca8..02ff0272b2e4 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7101,10 +7101,10 @@ static struct sched_group *
 find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu);
 
 /*
- * find_idlest_group_cpu - find the idlest CPU among the CPUs in the group.
+ * sched_balance_find_dst_group_cpu - find the idlest CPU among the CPUs in the group.
  */
 static int
-find_idlest_group_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
+sched_balance_find_dst_group_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
 {
 	unsigned long load, min_load = ULONG_MAX;
 	unsigned int min_exit_latency = UINT_MAX;
@@ -7191,7 +7191,7 @@ static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p
 			continue;
 		}
 
-		new_cpu = find_idlest_group_cpu(group, p, cpu);
+		new_cpu = sched_balance_find_dst_group_cpu(group, p, cpu);
 		if (new_cpu == cpu) {
 			/* Now try balancing at a lower domain level of 'cpu': */
 			sd = sd->child;
-- 
cgit v1.2.3


From a88b17080294f735c4124acccfa2d803a6a7d46f Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 12:18:18 +0100
Subject: sched/balancing: Rename find_idlest_group() =>
 sched_balance_find_dst_group()

Standardize scheduler load-balancing function names on the
sched_balance_() prefix.

Also use 'dst' instead of 'idlest', because it's not really
true that we return the 'idlest' group or CPU, we sort by
idle-exit latency and only return the idlest CPUs from the
lowest-latency set of CPUs.

The true 'idlest' CPUs often remain idle for a long time
and are never returned as long as the system is under-loaded.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-13-mingo@kernel.org
---
 kernel/sched/fair.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 02ff0272b2e4..d0c3a091d7d1 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7098,7 +7098,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p,
 }
 
 static struct sched_group *
-find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu);
+sched_balance_find_dst_group(struct sched_domain *sd, struct task_struct *p, int this_cpu);
 
 /*
  * sched_balance_find_dst_group_cpu - find the idlest CPU among the CPUs in the group.
@@ -7185,7 +7185,7 @@ static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p
 			continue;
 		}
 
-		group = find_idlest_group(sd, p, cpu);
+		group = sched_balance_find_dst_group(sd, p, cpu);
 		if (!group) {
 			sd = sd->child;
 			continue;
@@ -10296,13 +10296,13 @@ static bool update_pick_idlest(struct sched_group *idlest,
 }
 
 /*
- * find_idlest_group() finds and returns the least busy CPU group within the
+ * sched_balance_find_dst_group() finds and returns the least busy CPU group within the
  * domain.
  *
  * Assumes p is allowed on at least one CPU in sd.
  */
 static struct sched_group *
-find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
+sched_balance_find_dst_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
 {
 	struct sched_group *idlest = NULL, *local = NULL, *group = sd->groups;
 	struct sg_lb_stats local_sgs, tmp_sgs;
-- 
cgit v1.2.3


From 686d148cbb5a1c2891914b8d11147d3c5556a29a Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Fri, 8 Mar 2024 12:18:19 +0100
Subject: sched/balancing: Rename find_idlest_cpu() =>
 sched_balance_find_dst_cpu()

Standardize scheduler load-balancing function names on the
sched_balance_() prefix.

Also use 'dst' instead of 'idlest', because it's not really
true that we return the 'idlest' group or CPU, we sort by
idle-exit latency and only return the idlest CPUs from the
lowest-latency set of CPUs.

The true 'idlest' CPUs often remain idle for a long time
and are never returned as long as the system is under-loaded.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://lore.kernel.org/r/20240308111819.1101550-14-mingo@kernel.org
---
 kernel/sched/fair.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d0c3a091d7d1..4b3c4a181a91 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7160,7 +7160,7 @@ sched_balance_find_dst_group_cpu(struct sched_group *group, struct task_struct *
 	return shallowest_idle_cpu != -1 ? shallowest_idle_cpu : least_loaded_cpu;
 }
 
-static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p,
+static inline int sched_balance_find_dst_cpu(struct sched_domain *sd, struct task_struct *p,
 				  int cpu, int prev_cpu, int sd_flag)
 {
 	int new_cpu = cpu;
@@ -7936,7 +7936,7 @@ compute_energy(struct energy_env *eenv, struct perf_domain *pd,
  * NOTE: Forkees are not accepted in the energy-aware wake-up path because
  * they don't have any useful utilization data yet and it's not possible to
  * forecast their impact on energy consumption. Consequently, they will be
- * placed by find_idlest_cpu() on the least loaded CPU, which might turn out
+ * placed by sched_balance_find_dst_cpu() on the least loaded CPU, which might turn out
  * to be energy-inefficient in some use-cases. The alternative would be to
  * bias new tasks towards specific types of CPUs first, or to try to infer
  * their util_avg from the parent task, but those heuristics could hurt
@@ -8201,7 +8201,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int wake_flags)
 
 	if (unlikely(sd)) {
 		/* Slow path */
-		new_cpu = find_idlest_cpu(sd, p, cpu, prev_cpu, sd_flag);
+		new_cpu = sched_balance_find_dst_cpu(sd, p, cpu, prev_cpu, sd_flag);
 	} else if (wake_flags & WF_TTWU) { /* XXX always ? */
 		/* Fast path */
 		new_cpu = select_idle_sibling(p, prev_cpu, new_cpu);
-- 
cgit v1.2.3


From d72cf62438d67b911212f8d4cf65d6167c1541ba Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Tue, 12 Mar 2024 11:33:50 +0100
Subject: sched/balancing: Fix a couple of outdated function names in comments

The 'idle_balance()' function hasn't existed for years, and there's no
load_balance_newidle() either - both are sched_balance_newidle() today.

Reported-by: Honglei Wang <jameshongleiwang@126.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/ZfAwNufbiyt/5biu@gmail.com
---
 kernel/sched/fair.c | 2 +-
 kernel/sched/pelt.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4b3c4a181a91..a19ea290b790 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6866,7 +6866,7 @@ dequeue_throttle:
 
 #ifdef CONFIG_SMP
 
-/* Working cpumask for: sched_balance_rq, load_balance_newidle. */
+/* Working cpumask for: sched_balance_rq(), sched_balance_newidle(). */
 static DEFINE_PER_CPU(cpumask_var_t, load_balance_mask);
 static DEFINE_PER_CPU(cpumask_var_t, select_rq_mask);
 static DEFINE_PER_CPU(cpumask_var_t, should_we_balance_tmpmask);
diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c
index f80955ecdce6..3a96da25b67c 100644
--- a/kernel/sched/pelt.c
+++ b/kernel/sched/pelt.c
@@ -208,7 +208,7 @@ ___update_load_sum(u64 now, struct sched_avg *sa,
 	 * se has been already dequeued but cfs_rq->curr still points to it.
 	 * This means that weight will be 0 but not running for a sched_entity
 	 * but also for a cfs_rq if the latter becomes idle. As an example,
-	 * this happens during idle_balance() which calls
+	 * this happens during sched_balance_newidle() which calls
 	 * sched_balance_update_blocked_averages().
 	 *
 	 * Also see the comment in accumulate_sum().
-- 
cgit v1.2.3


From b9e6e28663928cab836a19abbdec3d036a07db3b Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@kernel.org>
Date: Thu, 14 Mar 2024 12:06:03 +0100
Subject: sched/fair: Fix typos in comments

So I made all speling mistakes / typos red in my editor. Big mistake...

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org
---
 kernel/sched/fair.c | 68 ++++++++++++++++++++++++++---------------------------
 1 file changed, 34 insertions(+), 34 deletions(-)

(limited to 'kernel')

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index a19ea290b790..c8e50fbac345 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -388,8 +388,8 @@ static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
 
 		/*
 		 * With cfs_rq being unthrottled/throttled during an enqueue,
-		 * it can happen the tmp_alone_branch points the a leaf that
-		 * we finally want to del. In this case, tmp_alone_branch moves
+		 * it can happen the tmp_alone_branch points to the leaf that
+		 * we finally want to delete. In this case, tmp_alone_branch moves
 		 * to the prev element but it will point to rq->leaf_cfs_rq_list
 		 * at the end of the enqueue.
 		 */
@@ -406,7 +406,7 @@ static inline void assert_list_leaf_cfs_rq(struct rq *rq)
 	SCHED_WARN_ON(rq->tmp_alone_branch != &rq->leaf_cfs_rq_list);
 }
 
-/* Iterate thr' all leaf cfs_rq's on a runqueue */
+/* Iterate through all leaf cfs_rq's on a runqueue */
 #define for_each_leaf_cfs_rq_safe(rq, cfs_rq, pos)			\
 	list_for_each_entry_safe(cfs_rq, pos, &rq->leaf_cfs_rq_list,	\
 				 leaf_cfs_rq_list)
@@ -595,13 +595,13 @@ static inline s64 entity_key(struct cfs_rq *cfs_rq, struct sched_entity *se)
  *
  * [[ NOTE: this is only equal to the ideal scheduler under the condition
  *          that join/leave operations happen at lag_i = 0, otherwise the
- *          virtual time has non-continguous motion equivalent to:
+ *          virtual time has non-contiguous motion equivalent to:
  *
  *	      V +-= lag_i / W
  *
  *	    Also see the comment in place_entity() that deals with this. ]]
  *
- * However, since v_i is u64, and the multiplcation could easily overflow
+ * However, since v_i is u64, and the multiplication could easily overflow
  * transform it into a relative form that uses smaller quantities:
  *
  * Substitute: v_i == (v_i - v0) + v0
@@ -671,7 +671,7 @@ u64 avg_vruntime(struct cfs_rq *cfs_rq)
 	}
 
 	if (load) {
-		/* sign flips effective floor / ceil */
+		/* sign flips effective floor / ceiling */
 		if (avg < 0)
 			avg -= (load - 1);
 		avg = div_s64(avg, load);
@@ -721,7 +721,7 @@ static void update_entity_lag(struct cfs_rq *cfs_rq, struct sched_entity *se)
  *
  * lag_i >= 0 -> \Sum (v_i - v)*w_i >= (v_i - v)*(\Sum w_i)
  *
- * Note: using 'avg_vruntime() > se->vruntime' is inacurate due
+ * Note: using 'avg_vruntime() > se->vruntime' is inaccurate due
  *       to the loss in precision caused by the division.
  */
 static int vruntime_eligible(struct cfs_rq *cfs_rq, u64 vruntime)
@@ -1024,7 +1024,7 @@ void init_entity_runnable_average(struct sched_entity *se)
 	if (entity_is_task(se))
 		sa->load_avg = scale_load_down(se->load.weight);
 
-	/* when this task enqueue'ed, it will contribute to its cfs_rq's load_avg */
+	/* when this task is enqueued, it will contribute to its cfs_rq's load_avg */
 }
 
 /*
@@ -1616,7 +1616,7 @@ static unsigned long score_nearby_nodes(struct task_struct *p, int nid,
 	max_dist = READ_ONCE(sched_max_numa_distance);
 	/*
 	 * This code is called for each node, introducing N^2 complexity,
-	 * which should be ok given the number of nodes rarely exceeds 8.
+	 * which should be OK given the number of nodes rarely exceeds 8.
 	 */
 	for_each_online_node(node) {
 		unsigned long faults;
@@ -3284,7 +3284,7 @@ retry_pids:
 		/*
 		 * Shared library pages mapped by multiple processes are not
 		 * migrated as it is expected they are cache replicated. Avoid
-		 * hinting faults in read-only file-backed mappings or the vdso
+		 * hinting faults in read-only file-backed mappings or the vDSO
 		 * as migrating the pages will be of marginal benefit.
 		 */
 		if (!vma->vm_mm ||
@@ -3295,7 +3295,7 @@ retry_pids:
 
 		/*
 		 * Skip inaccessible VMAs to avoid any confusion between
-		 * PROT_NONE and NUMA hinting ptes
+		 * PROT_NONE and NUMA hinting PTEs
 		 */
 		if (!vma_is_accessible(vma)) {
 			trace_sched_skip_vma_numa(mm, vma, NUMAB_SKIP_INACCESSIBLE);
@@ -3327,7 +3327,7 @@ retry_pids:
 		}
 
 		/*
-		 * Scanning the VMA's of short lived tasks add more overhead. So
+		 * Scanning the VMAs of short lived tasks add more overhead. So
 		 * delay the scan for new VMAs.
 		 */
 		if (mm->numa_scan_seq && time_before(jiffies,
@@ -3371,7 +3371,7 @@ retry_pids:
 			/*
 			 * Try to scan sysctl_numa_balancing_size worth of
 			 * hpages that have at least one present PTE that
-			 * is not already pte-numa. If the VMA contains
+			 * is not already PTE-numa. If the VMA contains
 			 * areas that are unused or already full of prot_numa
 			 * PTEs, scan up to virtpages, to skip through those
 			 * areas faster.
@@ -4733,7 +4733,7 @@ static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s
 
 	/*
 	 * Track task load average for carrying it to new CPU after migrated, and
-	 * track group sched_entity load average for task_h_load calc in migration
+	 * track group sched_entity load average for task_h_load calculation in migration
 	 */
 	if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD))
 		__update_load_avg_se(now, cfs_rq, se);
@@ -5014,14 +5014,14 @@ static inline int util_fits_cpu(unsigned long util,
 	 *   |     |   |       |   |      |   |
 	 *   |     |   |       |   |      |   |
 	 *   +----------------------------------------
-	 *         cpu0        cpu1       cpu2
+	 *         CPU0        CPU1       CPU2
 	 *
 	 *   In the above example if a task is capped to a specific performance
 	 *   point, y, then when:
 	 *
-	 *   * util = 80% of x then it does not fit on cpu0 and should migrate
-	 *     to cpu1
-	 *   * util = 80% of y then it is forced to fit on cpu1 to honour
+	 *   * util = 80% of x then it does not fit on CPU0 and should migrate
+	 *     to CPU1
+	 *   * util = 80% of y then it is forced to fit on CPU1 to honour
 	 *     uclamp_max request.
 	 *
 	 *   which is what we're enforcing here. A task always fits if
@@ -5052,7 +5052,7 @@ static inline int util_fits_cpu(unsigned long util,
 	 *   |     |   |       |   |      |   |
 	 *   |     |   |       |   |      |   |      (region c, boosted, util < uclamp_min)
 	 *   +----------------------------------------
-	 *         cpu0        cpu1       cpu2
+	 *         CPU0        CPU1       CPU2
 	 *
 	 * a) If util > uclamp_max, then we're capped, we don't care about
 	 *    actual fitness value here. We only care if uclamp_max fits
@@ -5242,7 +5242,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	se->vruntime = vruntime - lag;
 
 	/*
-	 * When joining the competition; the exisiting tasks will be,
+	 * When joining the competition; the existing tasks will be,
 	 * on average, halfway through their slice, as such start tasks
 	 * off with half a slice to ease into the competition.
 	 */
@@ -5391,7 +5391,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	 * Now advance min_vruntime if @se was the entity holding it back,
 	 * except when: DEQUEUE_SAVE && !DEQUEUE_MOVE, in this case we'll be
 	 * put back on, and if we advance min_vruntime, we'll be placed back
-	 * further than we started -- ie. we'll be penalized.
+	 * further than we started -- i.e. we'll be penalized.
 	 */
 	if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) != DEQUEUE_SAVE)
 		update_min_vruntime(cfs_rq);
@@ -5427,7 +5427,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
 
 	/*
 	 * Track our maximum slice length, if the CPU's load is at
-	 * least twice that of our own weight (i.e. dont track it
+	 * least twice that of our own weight (i.e. don't track it
 	 * when there are only lesser-weight tasks around):
 	 */
 	if (schedsta