Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c
index a96db50..2c613e1 100644
--- a/kernel/sched/pelt.c
+++ b/kernel/sched/pelt.c
@@ -28,8 +28,6 @@
#include "sched.h"
#include "pelt.h"
-#include <trace/events/sched.h>
-
/*
* Approximate:
* val * y^n, where y^32 ~= 0.5 (~1 scheduling period)
@@ -83,8 +81,6 @@
return c1 + c2 + c3;
}
-#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
-
/*
* Accumulate the three separate parts of the sum; d1 the remainder
* of the last (incomplete) period, d2 the span of full periods and d3
@@ -121,23 +117,35 @@
*/
if (periods) {
sa->load_sum = decay_load(sa->load_sum, periods);
- sa->runnable_load_sum =
- decay_load(sa->runnable_load_sum, periods);
+ sa->runnable_sum =
+ decay_load(sa->runnable_sum, periods);
sa->util_sum = decay_load((u64)(sa->util_sum), periods);
/*
* Step 2
*/
delta %= 1024;
- contrib = __accumulate_pelt_segments(periods,
- 1024 - sa->period_contrib, delta);
+ if (load) {
+ /*
+ * This relies on the:
+ *
+ * if (!load)
+ * runnable = running = 0;
+ *
+ * clause from ___update_load_sum(); this results in
+ * the below usage of @contrib to dissapear entirely,
+ * so no point in calculating it.
+ */
+ contrib = __accumulate_pelt_segments(periods,
+ 1024 - sa->period_contrib, delta);
+ }
}
sa->period_contrib = delta;
if (load)
sa->load_sum += load * contrib;
if (runnable)
- sa->runnable_load_sum += runnable * contrib;
+ sa->runnable_sum += runnable * contrib << SCHED_CAPACITY_SHIFT;
if (running)
sa->util_sum += contrib << SCHED_CAPACITY_SHIFT;
@@ -205,7 +213,9 @@
* 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()
+ * update_blocked_averages().
+ *
+ * Also see the comment in accumulate_sum().
*/
if (!load)
runnable = running = 0;
@@ -223,16 +233,40 @@
return 1;
}
+/*
+ * When syncing *_avg with *_sum, we must take into account the current
+ * position in the PELT segment otherwise the remaining part of the segment
+ * will be considered as idle time whereas it's not yet elapsed and this will
+ * generate unwanted oscillation in the range [1002..1024[.
+ *
+ * The max value of *_sum varies with the position in the time segment and is
+ * equals to :
+ *
+ * LOAD_AVG_MAX*y + sa->period_contrib
+ *
+ * which can be simplified into:
+ *
+ * LOAD_AVG_MAX - 1024 + sa->period_contrib
+ *
+ * because LOAD_AVG_MAX*y == LOAD_AVG_MAX-1024
+ *
+ * The same care must be taken when a sched entity is added, updated or
+ * removed from a cfs_rq and we need to update sched_avg. Scheduler entities
+ * and the cfs rq, to which they are attached, have the same position in the
+ * time segment because they use the same clock. This means that we can use
+ * the period_contrib of cfs_rq when updating the sched_avg of a sched_entity
+ * if it's more convenient.
+ */
static __always_inline void
-___update_load_avg(struct sched_avg *sa, unsigned long load, unsigned long runnable)
+___update_load_avg(struct sched_avg *sa, unsigned long load)
{
- u32 divider = LOAD_AVG_MAX - 1024 + sa->period_contrib;
+ u32 divider = get_pelt_divider(sa);
/*
* Step 2: update *_avg.
*/
sa->load_avg = div_u64(load * sa->load_sum, divider);
- sa->runnable_load_avg = div_u64(runnable * sa->runnable_load_sum, divider);
+ sa->runnable_avg = div_u64(sa->runnable_sum, divider);
WRITE_ONCE(sa->util_avg, sa->util_sum / divider);
}
@@ -240,33 +274,32 @@
* sched_entity:
*
* task:
- * se_runnable() == se_weight()
+ * se_weight() = se->load.weight
+ * se_runnable() = !!on_rq
*
* group: [ see update_cfs_group() ]
* se_weight() = tg->weight * grq->load_avg / tg->load_avg
- * se_runnable() = se_weight(se) * grq->runnable_load_avg / grq->load_avg
+ * se_runnable() = grq->h_nr_running
*
- * load_sum := runnable_sum
- * load_avg = se_weight(se) * runnable_avg
+ * runnable_sum = se_runnable() * runnable = grq->runnable_sum
+ * runnable_avg = runnable_sum
*
- * runnable_load_sum := runnable_sum
- * runnable_load_avg = se_runnable(se) * runnable_avg
- *
- * XXX collapse load_sum and runnable_load_sum
+ * load_sum := runnable
+ * load_avg = se_weight(se) * load_sum
*
* cfq_rq:
*
+ * runnable_sum = \Sum se->avg.runnable_sum
+ * runnable_avg = \Sum se->avg.runnable_avg
+ *
* load_sum = \Sum se_weight(se) * se->avg.load_sum
* load_avg = \Sum se->avg.load_avg
- *
- * runnable_load_sum = \Sum se_runnable(se) * se->avg.runnable_load_sum
- * runnable_load_avg = \Sum se->avg.runable_load_avg
*/
int __update_load_avg_blocked_se(u64 now, struct sched_entity *se)
{
if (___update_load_sum(now, &se->avg, 0, 0, 0)) {
- ___update_load_avg(&se->avg, se_weight(se), se_runnable(se));
+ ___update_load_avg(&se->avg, se_weight(se));
trace_pelt_se_tp(se);
return 1;
}
@@ -276,10 +309,10 @@
int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- if (___update_load_sum(now, &se->avg, !!se->on_rq, !!se->on_rq,
+ if (___update_load_sum(now, &se->avg, !!se->on_rq, se_runnable(se),
cfs_rq->curr == se)) {
- ___update_load_avg(&se->avg, se_weight(se), se_runnable(se));
+ ___update_load_avg(&se->avg, se_weight(se));
cfs_se_util_change(&se->avg);
trace_pelt_se_tp(se);
return 1;
@@ -292,10 +325,10 @@
{
if (___update_load_sum(now, &cfs_rq->avg,
scale_load_down(cfs_rq->load.weight),
- scale_load_down(cfs_rq->runnable_weight),
+ cfs_rq->h_nr_running,
cfs_rq->curr != NULL)) {
- ___update_load_avg(&cfs_rq->avg, 1, 1);
+ ___update_load_avg(&cfs_rq->avg, 1);
trace_pelt_cfs_tp(cfs_rq);
return 1;
}
@@ -308,9 +341,9 @@
*
* util_sum = \Sum se->avg.util_sum but se->avg.util_sum is not tracked
* util_sum = cpu_scale * load_sum
- * runnable_load_sum = load_sum
+ * runnable_sum = util_sum
*
- * load_avg and runnable_load_avg are not supported and meaningless.
+ * load_avg and runnable_avg are not supported and meaningless.
*
*/
@@ -321,7 +354,7 @@
running,
running)) {
- ___update_load_avg(&rq->avg_rt, 1, 1);
+ ___update_load_avg(&rq->avg_rt, 1);
trace_pelt_rt_tp(rq);
return 1;
}
@@ -334,7 +367,9 @@
*
* util_sum = \Sum se->avg.util_sum but se->avg.util_sum is not tracked
* util_sum = cpu_scale * load_sum
- * runnable_load_sum = load_sum
+ * runnable_sum = util_sum
+ *
+ * load_avg and runnable_avg are not supported and meaningless.
*
*/
@@ -345,7 +380,7 @@
running,
running)) {
- ___update_load_avg(&rq->avg_dl, 1, 1);
+ ___update_load_avg(&rq->avg_dl, 1);
trace_pelt_dl_tp(rq);
return 1;
}
@@ -353,13 +388,46 @@
return 0;
}
+#ifdef CONFIG_SCHED_THERMAL_PRESSURE
+/*
+ * thermal:
+ *
+ * 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
+ * time weighted "delta" capacity unlike util_avg which is binary.
+ * "delta capacity" = actual capacity -
+ * capped capacity a cpu due to a thermal event.
+ */
+
+int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity)
+{
+ if (___update_load_sum(now, &rq->avg_thermal,
+ capacity,
+ capacity,
+ capacity)) {
+ ___update_load_avg(&rq->avg_thermal, 1);
+ trace_pelt_thermal_tp(rq);
+ return 1;
+ }
+
+ return 0;
+}
+#endif
+
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
/*
* irq:
*
* util_sum = \Sum se->avg.util_sum but se->avg.util_sum is not tracked
* util_sum = cpu_scale * load_sum
- * runnable_load_sum = load_sum
+ * runnable_sum = util_sum
+ *
+ * load_avg and runnable_avg are not supported and meaningless.
*
*/
@@ -396,7 +464,7 @@
1);
if (ret) {
- ___update_load_avg(&rq->avg_irq, 1, 1);
+ ___update_load_avg(&rq->avg_irq, 1);
trace_pelt_irq_tp(rq);
}