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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt16
-rw-r--r--kernel/sched/core.c2
-rw-r--r--kernel/sched/fair.c15
-rw-r--r--kernel/sched/sched.h18
4 files changed, 49 insertions, 2 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index c07815d230bc..dac8245ef588 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4392,6 +4392,22 @@
incurs a small amount of overhead in the scheduler
but is useful for debugging and performance tuning.
+ sched_thermal_decay_shift=
+ [KNL, SMP] Set a decay shift for scheduler thermal
+ pressure signal. Thermal pressure signal follows the
+ default decay period of other scheduler pelt
+ signals(usually 32 ms but configurable). Setting
+ sched_thermal_decay_shift will left shift the decay
+ period for the thermal pressure signal by the shift
+ value.
+ i.e. with the default pelt decay period of 32 ms
+ sched_thermal_decay_shift thermal pressure decay pr
+ 1 64 ms
+ 2 128 ms
+ and so on.
+ Format: integer between 0 and 10
+ Default is 0.
+
skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate
xtime_lock contention on larger systems, and/or RCU lock
contention on all systems with CONFIG_MAXSMP set.
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3e620fe8e3a0..4d76df33418e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3595,7 +3595,7 @@ void scheduler_tick(void)
update_rq_clock(rq);
thermal_pressure = arch_scale_thermal_pressure(cpu_of(rq));
- update_thermal_load_avg(rq_clock_task(rq), rq, thermal_pressure);
+ update_thermal_load_avg(rq_clock_thermal(rq), rq, thermal_pressure);
curr->sched_class->task_tick(rq, curr, 0);
calc_global_load_tick(rq);
psi_task_tick(rq);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index aa51286c66da..79bb423de1e6 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -86,6 +86,19 @@ static unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL;
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
+int sched_thermal_decay_shift;
+static int __init setup_sched_thermal_decay_shift(char *str)
+{
+ int _shift = 0;
+
+ 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);
+ return 1;
+}
+__setup("sched_thermal_decay_shift=", setup_sched_thermal_decay_shift);
+
#ifdef CONFIG_SMP
/*
* For asym packing, by default the lower numbered CPU has higher priority.
@@ -7760,7 +7773,7 @@ static bool __update_blocked_others(struct rq *rq, bool *done)
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_task(rq), rq, thermal_pressure) |
+ update_thermal_load_avg(rq_clock_thermal(rq), rq, thermal_pressure) |
update_irq_load_avg(rq, 0);
if (others_have_blocked(rq))
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 6c839f829a25..7f1a85bd540d 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1127,6 +1127,24 @@ static inline u64 rq_clock_task(struct rq *rq)
return rq->clock_task;
}
+/**
+ * By default the decay is the default pelt decay period.
+ * The decay shift can change the decay period in
+ * multiples of 32.
+ * Decay shift Decay period(ms)
+ * 0 32
+ * 1 64
+ * 2 128
+ * 3 256
+ * 4 512
+ */
+extern int sched_thermal_decay_shift;
+
+static inline u64 rq_clock_thermal(struct rq *rq)
+{
+ return rq_clock_task(rq) >> sched_thermal_decay_shift;
+}
+
static inline void rq_clock_skip_update(struct rq *rq)
{
lockdep_assert_held(&rq->lock);