sched/cpufreq: Rename arch_update_thermal_pressure() => arch_update_hw_pressure()

Now that cpufreq provides a pressure value to the scheduler, rename
arch_update_thermal_pressure into HW pressure to reflect that it returns
a pressure applied by HW (i.e. with a high frequency change) and not
always related to thermal mitigation but also generated by max current
limitation as an example. Such high frequency signal needs filtering to be
smoothed and provide an value that reflects the average available capacity
into the scheduler time scale.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Qais Yousef <qyousef@layalina.io>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20240326091616.3696851-5-vincent.guittot@linaro.org

5 files changed, 34 insertions, 34 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 0621e4ee31de..67a8302c3131 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -108,7 +108,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_rt_tp);
 EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_dl_tp);
 EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_irq_tp);
 EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_se_tp);
-EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_thermal_tp);
+EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_hw_tp);
 EXPORT_TRACEPOINT_SYMBOL_GPL(sched_cpu_capacity_tp);
 EXPORT_TRACEPOINT_SYMBOL_GPL(sched_overutilized_tp);
 EXPORT_TRACEPOINT_SYMBOL_GPL(sched_util_est_cfs_tp);
@@ -5668,7 +5668,7 @@ void sched_tick(void)
 	struct rq *rq = cpu_rq(cpu);
 	struct task_struct *curr = rq->curr;
 	struct rq_flags rf;
-	unsigned long thermal_pressure;
+	unsigned long hw_pressure;
 	u64 resched_latency;
 
 	if (housekeeping_cpu(cpu, HK_TYPE_TICK))
@@ -5679,8 +5679,8 @@ void sched_tick(void)
 	rq_lock(rq, &rf);
 
 	update_rq_clock(rq);
-	thermal_pressure = arch_scale_thermal_pressure(cpu_of(rq));
-	update_thermal_load_avg(rq_clock_thermal(rq), rq, thermal_pressure);
+	hw_pressure = arch_scale_hw_pressure(cpu_of(rq));
+	update_hw_load_avg(rq_clock_hw(rq), rq, hw_pressure);
 	curr->sched_class->task_tick(rq, curr, 0);
 	if (sched_feat(LATENCY_WARN))
 		resched_latency = cpu_resched_latency(rq);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 19199c119829..eef39ae3efcf 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -78,7 +78,7 @@ static unsigned int normalized_sysctl_sched_base_slice	= 750000ULL;
 
 const_debug unsigned int sysctl_sched_migration_cost	= 500000UL;
 
-int sched_thermal_decay_shift;
+int sched_hw_decay_shift;
 static int __init setup_sched_thermal_decay_shift(char *str)
 {
 	int _shift = 0;
@@ -86,7 +86,7 @@ static int __init setup_sched_thermal_decay_shift(char *str)
 	if (kstrtoint(str, 0, &_shift))
 		pr_warn("Unable to set scheduler thermal pressure decay shift parameter\n");
 
-	sched_thermal_decay_shift = clamp(_shift, 0, 10);
+	sched_hw_decay_shift = clamp(_shift, 0, 10);
 	return 1;
 }
 __setup("sched_thermal_decay_shift=", setup_sched_thermal_decay_shift);
@@ -4969,7 +4969,7 @@ static inline unsigned long get_actual_cpu_capacity(int cpu)
 {
 	unsigned long capacity = arch_scale_cpu_capacity(cpu);
 
-	capacity -= max(thermal_load_avg(cpu_rq(cpu)), cpufreq_get_pressure(cpu));
+	capacity -= max(hw_load_avg(cpu_rq(cpu)), cpufreq_get_pressure(cpu));
 
 	return capacity;
 }
@@ -5002,7 +5002,7 @@ static inline int util_fits_cpu(unsigned long util,
 	 * Similarly if a task is capped to arch_scale_cpu_capacity(little_cpu), it
 	 * should fit a little cpu even if there's some pressure.
 	 *
-	 * Only exception is for thermal pressure since it has a direct impact
+	 * Only exception is for HW or cpufreq pressure since it has a direct impact
 	 * on available OPP of the system.
 	 *
 	 * We honour it for uclamp_min only as a drop in performance level
@@ -9324,7 +9324,7 @@ static inline bool others_have_blocked(struct rq *rq)
 	if (cpu_util_dl(rq))
 		return true;
 
-	if (thermal_load_avg(rq))
+	if (hw_load_avg(rq))
 		return true;
 
 	if (cpu_util_irq(rq))
@@ -9354,7 +9354,7 @@ static bool __update_blocked_others(struct rq *rq, bool *done)
 {
 	const struct sched_class *curr_class;
 	u64 now = rq_clock_pelt(rq);
-	unsigned long thermal_pressure;
+	unsigned long hw_pressure;
 	bool decayed;
 
 	/*
@@ -9363,11 +9363,11 @@ static bool __update_blocked_others(struct rq *rq, bool *done)
 	 */
 	curr_class = rq->curr->sched_class;
 
-	thermal_pressure = arch_scale_thermal_pressure(cpu_of(rq));
+	hw_pressure = arch_scale_hw_pressure(cpu_of(rq));
 
 	decayed = update_rt_rq_load_avg(now, rq, curr_class == &rt_sched_class) |
 		  update_dl_rq_load_avg(now, rq, curr_class == &dl_sched_class) |
-		  update_thermal_load_avg(rq_clock_thermal(rq), rq, thermal_pressure) |
+		  update_hw_load_avg(rq_clock_hw(rq), rq, hw_pressure) |
 		  update_irq_load_avg(rq, 0);
 
 	if (others_have_blocked(rq))
diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c
index 3a96da25b67c..ef00382de595 100644
--- a/kernel/sched/pelt.c
+++ b/kernel/sched/pelt.c
@@ -384,30 +384,30 @@ int update_dl_rq_load_avg(u64 now, struct rq *rq, int running)
 	return 0;
 }
 
-#ifdef CONFIG_SCHED_THERMAL_PRESSURE
+#ifdef CONFIG_SCHED_HW_PRESSURE
 /*
- * thermal:
+ * hardware:
  *
  *   load_sum = \Sum se->avg.load_sum but se->avg.load_sum is not tracked
  *
  *   util_avg and runnable_load_avg are not supported and meaningless.
  *
  * Unlike rt/dl utilization tracking that track time spent by a cpu
- * running a rt/dl task through util_avg, the average thermal pressure is
- * tracked through load_avg. This is because thermal pressure signal is
+ * running a rt/dl task through util_avg, the average HW pressure is
+ * tracked through load_avg. This is because HW pressure signal is
  * time weighted "delta" capacity unlike util_avg which is binary.
  * "delta capacity" =  actual capacity  -
- *			capped capacity a cpu due to a thermal event.
+ *			capped capacity a cpu due to a HW event.
  */
 
-int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
+int update_hw_load_avg(u64 now, struct rq *rq, u64 capacity)
 {
-	if (___update_load_sum(now, &rq->avg_thermal,
+	if (___update_load_sum(now, &rq->avg_hw,
 			       capacity,
 			       capacity,
 			       capacity)) {
-		___update_load_avg(&rq->avg_thermal, 1);
-		trace_pelt_thermal_tp(rq);
+		___update_load_avg(&rq->avg_hw, 1);
+		trace_pelt_hw_tp(rq);
 		return 1;
 	}
 
diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h
index 9e1083465fbc..2150062949d4 100644
--- a/kernel/sched/pelt.h
+++ b/kernel/sched/pelt.h
@@ -7,21 +7,21 @@ int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq);
 int update_rt_rq_load_avg(u64 now, struct rq *rq, int running);
 int update_dl_rq_load_avg(u64 now, struct rq *rq, int running);
 
-#ifdef CONFIG_SCHED_THERMAL_PRESSURE
-int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity);
+#ifdef CONFIG_SCHED_HW_PRESSURE
+int update_hw_load_avg(u64 now, struct rq *rq, u64 capacity);
 
-static inline u64 thermal_load_avg(struct rq *rq)
+static inline u64 hw_load_avg(struct rq *rq)
 {
-	return READ_ONCE(rq->avg_thermal.load_avg);
+	return READ_ONCE(rq->avg_hw.load_avg);
 }
 #else
 static inline int
-update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
+update_hw_load_avg(u64 now, struct rq *rq, u64 capacity)
 {
 	return 0;
 }
 
-static inline u64 thermal_load_avg(struct rq *rq)
+static inline u64 hw_load_avg(struct rq *rq)
 {
 	return 0;
 }
@@ -202,12 +202,12 @@ update_dl_rq_load_avg(u64 now, struct rq *rq, int running)
 }
 
 static inline int
-update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
+update_hw_load_avg(u64 now, struct rq *rq, u64 capacity)
 {
 	return 0;
 }
 
-static inline u64 thermal_load_avg(struct rq *rq)
+static inline u64 hw_load_avg(struct rq *rq)
 {
 	return 0;
 }
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 7c39dbf31f75..993edb02fb0d 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1108,8 +1108,8 @@ struct rq {
 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
 	struct sched_avg	avg_irq;
 #endif
-#ifdef CONFIG_SCHED_THERMAL_PRESSURE
-	struct sched_avg	avg_thermal;
+#ifdef CONFIG_SCHED_HW_PRESSURE
+	struct sched_avg	avg_hw;
 #endif
 	u64			idle_stamp;
 	u64			avg_idle;
@@ -1561,11 +1561,11 @@ static inline u64 rq_clock_task(struct rq *rq)
  *	3			256
  *	4			512
  */
-extern int sched_thermal_decay_shift;
+extern int sched_hw_decay_shift;
 
-static inline u64 rq_clock_thermal(struct rq *rq)
+static inline u64 rq_clock_hw(struct rq *rq)
 {
-	return rq_clock_task(rq) >> sched_thermal_decay_shift;
+	return rq_clock_task(rq) >> sched_hw_decay_shift;
 }
 
 static inline void rq_clock_skip_update(struct rq *rq)