[PATCH v3] sched/fair: filter out overloaded cpus in SIS
From: Abel Wu
Date: Thu May 05 2022 - 08:23:46 EST
Try to improve searching efficiency of SIS by filtering out the
overloaded cpus, and as a result the more overloaded the system
is, the less cpus will be searched.
The overloaded cpus are tracked through LLC shared domain. To
regulate accesses to the shared data, the update happens mainly
at the tick. But in order to make it more accurate, we also take
the task migrations into consideration during load balancing which
can be quite frequent due to short running workload causing newly-
idle. Since an overloaded runqueue requires at least 2 non-idle
tasks runnable, we could have more faith on the "frequent newly-
idle" case.
Benchmark
=========
Tests are done in an Intel(R) Xeon(R) Platinum 8260 CPU@2.40GHz
machine with 2 NUMA nodes each of which has 24 cores with SMT2
enabled, so 96 CPUs in total.
All of the benchmarks are done inside a normal cpu cgroup in a
clean environment with cpu turbo disabled.
Based on tip sched/core 089c02ae2771 (v5.18-rc1).
Results
=======
hackbench-process-pipes
vanilla filter
Amean 1 0.2537 ( 0.00%) 0.2330 ( 8.15%)
Amean 4 0.7090 ( 0.00%) 0.7440 * -4.94%*
Amean 7 0.9153 ( 0.00%) 0.9040 ( 1.24%)
Amean 12 1.1473 ( 0.00%) 1.0857 * 5.37%*
Amean 21 2.7210 ( 0.00%) 2.2320 * 17.97%*
Amean 30 4.8263 ( 0.00%) 3.6170 * 25.06%*
Amean 48 7.4107 ( 0.00%) 6.1130 * 17.51%*
Amean 79 9.2120 ( 0.00%) 8.2350 * 10.61%*
Amean 110 10.1647 ( 0.00%) 8.8043 * 13.38%*
Amean 141 11.5713 ( 0.00%) 10.5867 * 8.51%*
Amean 172 13.7963 ( 0.00%) 12.8120 * 7.13%*
Amean 203 15.9283 ( 0.00%) 14.8703 * 6.64%*
Amean 234 17.8737 ( 0.00%) 17.1053 * 4.30%*
Amean 265 19.8443 ( 0.00%) 18.7870 * 5.33%*
Amean 296 22.4147 ( 0.00%) 21.3943 * 4.55%*
There is a regression in 4-groups test in which case lots of busy
cpus can be found in the system. The busy cpus are not recorded in
the overloaded cpu mask, so we trade overhead for nothing in SIS.
This is the worst case of this feature.
hackbench-process-sockets
vanilla filter
Amean 1 0.5343 ( 0.00%) 0.5270 ( 1.37%)
Amean 4 1.4500 ( 0.00%) 1.4273 * 1.56%*
Amean 7 2.4813 ( 0.00%) 2.4383 * 1.73%*
Amean 12 4.1357 ( 0.00%) 4.0827 * 1.28%*
Amean 21 6.9707 ( 0.00%) 6.9290 ( 0.60%)
Amean 30 9.8373 ( 0.00%) 9.6730 * 1.67%*
Amean 48 15.6233 ( 0.00%) 15.3213 * 1.93%*
Amean 79 26.2763 ( 0.00%) 25.3293 * 3.60%*
Amean 110 36.6170 ( 0.00%) 35.8920 * 1.98%*
Amean 141 47.0720 ( 0.00%) 45.8773 * 2.54%*
Amean 172 57.0580 ( 0.00%) 56.1627 * 1.57%*
Amean 203 67.2040 ( 0.00%) 66.4323 * 1.15%*
Amean 234 77.8897 ( 0.00%) 76.6320 * 1.61%*
Amean 265 88.0437 ( 0.00%) 87.1400 ( 1.03%)
Amean 296 98.2387 ( 0.00%) 96.8633 * 1.40%*
hackbench-thread-pipes
vanilla filter
Amean 1 0.2693 ( 0.00%) 0.2800 * -3.96%*
Amean 4 0.7843 ( 0.00%) 0.7680 ( 2.08%)
Amean 7 0.9287 ( 0.00%) 0.9217 ( 0.75%)
Amean 12 1.4443 ( 0.00%) 1.3680 * 5.29%*
Amean 21 3.5150 ( 0.00%) 3.1107 * 11.50%*
Amean 30 6.3997 ( 0.00%) 5.2160 * 18.50%*
Amean 48 8.4183 ( 0.00%) 7.8477 * 6.78%*
Amean 79 10.0713 ( 0.00%) 9.2240 * 8.41%*
Amean 110 10.9940 ( 0.00%) 10.1280 * 7.88%*
Amean 141 13.6347 ( 0.00%) 11.9387 * 12.44%*
Amean 172 15.0523 ( 0.00%) 14.4117 ( 4.26%)
Amean 203 18.0710 ( 0.00%) 17.3533 ( 3.97%)
Amean 234 19.7413 ( 0.00%) 19.8453 ( -0.53%)
Amean 265 23.1820 ( 0.00%) 22.8223 ( 1.55%)
Amean 296 25.3820 ( 0.00%) 24.2397 ( 4.50%)
hackbench-thread-sockets
vanilla filter
Amean 1 0.5893 ( 0.00%) 0.5750 * 2.43%*
Amean 4 1.4853 ( 0.00%) 1.4727 ( 0.85%)
Amean 7 2.5353 ( 0.00%) 2.5047 * 1.21%*
Amean 12 4.3003 ( 0.00%) 4.1910 * 2.54%*
Amean 21 7.1930 ( 0.00%) 7.1533 ( 0.55%)
Amean 30 10.0983 ( 0.00%) 9.9690 * 1.28%*
Amean 48 15.9853 ( 0.00%) 15.6963 * 1.81%*
Amean 79 26.7537 ( 0.00%) 25.9497 * 3.01%*
Amean 110 37.3850 ( 0.00%) 36.6793 * 1.89%*
Amean 141 47.7730 ( 0.00%) 47.0967 * 1.42%*
Amean 172 58.4280 ( 0.00%) 57.5513 * 1.50%*
Amean 203 69.3093 ( 0.00%) 67.7680 * 2.22%*
Amean 234 80.0190 ( 0.00%) 78.2633 * 2.19%*
Amean 265 90.7237 ( 0.00%) 89.1027 * 1.79%*
Amean 296 101.1153 ( 0.00%) 99.2693 * 1.83%*
schbench
vanilla filter
Lat 50.0th-qrtle-1 5.00 ( 0.00%) 5.00 ( 0.00%)
Lat 75.0th-qrtle-1 5.00 ( 0.00%) 5.00 ( 0.00%)
Lat 90.0th-qrtle-1 5.00 ( 0.00%) 5.00 ( 0.00%)
Lat 95.0th-qrtle-1 5.00 ( 0.00%) 5.00 ( 0.00%)
Lat 99.0th-qrtle-1 6.00 ( 0.00%) 6.00 ( 0.00%)
Lat 99.5th-qrtle-1 7.00 ( 0.00%) 6.00 ( 14.29%)
Lat 99.9th-qrtle-1 7.00 ( 0.00%) 7.00 ( 0.00%)
Lat 50.0th-qrtle-2 6.00 ( 0.00%) 6.00 ( 0.00%)
Lat 75.0th-qrtle-2 7.00 ( 0.00%) 7.00 ( 0.00%)
Lat 90.0th-qrtle-2 7.00 ( 0.00%) 7.00 ( 0.00%)
Lat 95.0th-qrtle-2 7.00 ( 0.00%) 7.00 ( 0.00%)
Lat 99.0th-qrtle-2 9.00 ( 0.00%) 8.00 ( 11.11%)
Lat 99.5th-qrtle-2 9.00 ( 0.00%) 9.00 ( 0.00%)
Lat 99.9th-qrtle-2 12.00 ( 0.00%) 11.00 ( 8.33%)
Lat 50.0th-qrtle-4 8.00 ( 0.00%) 8.00 ( 0.00%)
Lat 75.0th-qrtle-4 10.00 ( 0.00%) 10.00 ( 0.00%)
Lat 90.0th-qrtle-4 10.00 ( 0.00%) 11.00 ( -10.00%)
Lat 95.0th-qrtle-4 11.00 ( 0.00%) 11.00 ( 0.00%)
Lat 99.0th-qrtle-4 12.00 ( 0.00%) 13.00 ( -8.33%)
Lat 99.5th-qrtle-4 16.00 ( 0.00%) 14.00 ( 12.50%)
Lat 99.9th-qrtle-4 17.00 ( 0.00%) 15.00 ( 11.76%)
Lat 50.0th-qrtle-8 13.00 ( 0.00%) 13.00 ( 0.00%)
Lat 75.0th-qrtle-8 16.00 ( 0.00%) 16.00 ( 0.00%)
Lat 90.0th-qrtle-8 18.00 ( 0.00%) 18.00 ( 0.00%)
Lat 95.0th-qrtle-8 19.00 ( 0.00%) 18.00 ( 5.26%)
Lat 99.0th-qrtle-8 24.00 ( 0.00%) 21.00 ( 12.50%)
Lat 99.5th-qrtle-8 28.00 ( 0.00%) 26.00 ( 7.14%)
Lat 99.9th-qrtle-8 33.00 ( 0.00%) 32.00 ( 3.03%)
Lat 50.0th-qrtle-16 20.00 ( 0.00%) 20.00 ( 0.00%)
Lat 75.0th-qrtle-16 28.00 ( 0.00%) 28.00 ( 0.00%)
Lat 90.0th-qrtle-16 32.00 ( 0.00%) 32.00 ( 0.00%)
Lat 95.0th-qrtle-16 34.00 ( 0.00%) 34.00 ( 0.00%)
Lat 99.0th-qrtle-16 40.00 ( 0.00%) 40.00 ( 0.00%)
Lat 99.5th-qrtle-16 44.00 ( 0.00%) 44.00 ( 0.00%)
Lat 99.9th-qrtle-16 53.00 ( 0.00%) 67.00 ( -26.42%)
Lat 50.0th-qrtle-32 39.00 ( 0.00%) 36.00 ( 7.69%)
Lat 75.0th-qrtle-32 57.00 ( 0.00%) 52.00 ( 8.77%)
Lat 90.0th-qrtle-32 69.00 ( 0.00%) 61.00 ( 11.59%)
Lat 95.0th-qrtle-32 76.00 ( 0.00%) 64.00 ( 15.79%)
Lat 99.0th-qrtle-32 88.00 ( 0.00%) 74.00 ( 15.91%)
Lat 99.5th-qrtle-32 91.00 ( 0.00%) 80.00 ( 12.09%)
Lat 99.9th-qrtle-32 115.00 ( 0.00%) 107.00 ( 6.96%)
Lat 50.0th-qrtle-47 63.00 ( 0.00%) 55.00 ( 12.70%)
Lat 75.0th-qrtle-47 93.00 ( 0.00%) 80.00 ( 13.98%)
Lat 90.0th-qrtle-47 116.00 ( 0.00%) 97.00 ( 16.38%)
Lat 95.0th-qrtle-47 129.00 ( 0.00%) 106.00 ( 17.83%)
Lat 99.0th-qrtle-47 148.00 ( 0.00%) 123.00 ( 16.89%)
Lat 99.5th-qrtle-47 157.00 ( 0.00%) 132.00 ( 15.92%)
Lat 99.9th-qrtle-47 387.00 ( 0.00%) 164.00 ( 57.62%)
netperf-udp
vanilla filter
Hmean send-64 183.09 ( 0.00%) 182.28 ( -0.44%)
Hmean send-128 364.68 ( 0.00%) 363.12 ( -0.43%)
Hmean send-256 715.38 ( 0.00%) 716.57 ( 0.17%)
Hmean send-1024 2764.76 ( 0.00%) 2779.17 ( 0.52%)
Hmean send-2048 5282.93 ( 0.00%) 5220.41 * -1.18%*
Hmean send-3312 8282.26 ( 0.00%) 8121.78 * -1.94%*
Hmean send-4096 10108.12 ( 0.00%) 10042.98 ( -0.64%)
Hmean send-8192 16868.49 ( 0.00%) 16826.99 ( -0.25%)
Hmean send-16384 26230.44 ( 0.00%) 26271.85 ( 0.16%)
Hmean recv-64 183.09 ( 0.00%) 182.28 ( -0.44%)
Hmean recv-128 364.68 ( 0.00%) 363.12 ( -0.43%)
Hmean recv-256 715.38 ( 0.00%) 716.57 ( 0.17%)
Hmean recv-1024 2764.76 ( 0.00%) 2779.17 ( 0.52%)
Hmean recv-2048 5282.93 ( 0.00%) 5220.39 * -1.18%*
Hmean recv-3312 8282.26 ( 0.00%) 8121.78 * -1.94%*
Hmean recv-4096 10108.12 ( 0.00%) 10042.97 ( -0.64%)
Hmean recv-8192 16868.47 ( 0.00%) 16826.93 ( -0.25%)
Hmean recv-16384 26230.44 ( 0.00%) 26271.75 ( 0.16%)
The overhead this feature added to the scheduler can be unfriendly
to the fast context-switching workloads like netperf/tbench. But
the test result seems fine.
netperf-tcp
vanilla filter
Hmean 64 863.35 ( 0.00%) 1176.11 * 36.23%*
Hmean 128 1674.32 ( 0.00%) 2223.37 * 32.79%*
Hmean 256 3151.03 ( 0.00%) 4109.64 * 30.42%*
Hmean 1024 10281.94 ( 0.00%) 12799.28 * 24.48%*
Hmean 2048 16906.05 ( 0.00%) 20129.91 * 19.07%*
Hmean 3312 21246.21 ( 0.00%) 24747.24 * 16.48%*
Hmean 4096 23690.57 ( 0.00%) 26596.35 * 12.27%*
Hmean 8192 28758.29 ( 0.00%) 30423.10 * 5.79%*
Hmean 16384 33071.06 ( 0.00%) 34262.39 * 3.60%*
The suspicious improvement (and regression in tbench4-128) needs
further digging..
tbench4 Throughput
vanilla filter
Hmean 1 293.71 ( 0.00%) 298.89 * 1.76%*
Hmean 2 583.25 ( 0.00%) 596.00 * 2.19%*
Hmean 4 1162.40 ( 0.00%) 1176.73 * 1.23%*
Hmean 8 2309.28 ( 0.00%) 2332.89 * 1.02%*
Hmean 16 4517.23 ( 0.00%) 4587.60 * 1.56%*
Hmean 32 7458.54 ( 0.00%) 7550.19 * 1.23%*
Hmean 64 9041.62 ( 0.00%) 9192.69 * 1.67%*
Hmean 128 19983.62 ( 0.00%) 12228.91 * -38.81%*
Hmean 256 20054.12 ( 0.00%) 20997.33 * 4.70%*
Hmean 384 19137.11 ( 0.00%) 20331.14 * 6.24%*
v3:
- removed sched-idle balance feature and focus on SIS
- take non-CFS tasks into consideration
- several fixes/improvement suggested by Josh Don
v2:
- several optimizations on sched-idle balancing
- ignore asym topos in can_migrate_task
- add more benchmarks including SIS efficiency
- re-organize patch as suggested by Mel
v1: https://lore.kernel.org/lkml/20220217154403.6497-5-wuyun.abel@xxxxxxxxxxxxx/
v2: https://lore.kernel.org/lkml/20220409135104.3733193-1-wuyun.abel@xxxxxxxxxxxxx/
Signed-off-by: Abel Wu <wuyun.abel@xxxxxxxxxxxxx>
---
include/linux/sched/topology.h | 12 ++++++++++
kernel/sched/core.c | 38 ++++++++++++++++++++++++++++++
kernel/sched/fair.c | 43 +++++++++++++++++++++++++++-------
kernel/sched/idle.c | 1 +
kernel/sched/sched.h | 4 ++++
kernel/sched/topology.c | 4 +++-
6 files changed, 92 insertions(+), 10 deletions(-)
diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h
index 56cffe42abbc..95c7ad1e05b5 100644
--- a/include/linux/sched/topology.h
+++ b/include/linux/sched/topology.h
@@ -81,8 +81,20 @@ struct sched_domain_shared {
atomic_t ref;
atomic_t nr_busy_cpus;
int has_idle_cores;
+
+ /*
+ * Tracking of the overloaded cpus can be heavy, so start
+ * a new cacheline to avoid false sharing.
+ */
+ atomic_t nr_overloaded_cpus ____cacheline_aligned;
+ unsigned long overloaded_cpus[]; /* Must be last */
};
+static inline struct cpumask *sdo_mask(struct sched_domain_shared *sds)
+{
+ return to_cpumask(sds->overloaded_cpus);
+}
+
struct sched_domain {
/* These fields must be setup */
struct sched_domain __rcu *parent; /* top domain must be null terminated */
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 51efaabac3e4..a29801c8b363 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5320,6 +5320,42 @@ __setup("resched_latency_warn_ms=", setup_resched_latency_warn_ms);
static inline u64 cpu_resched_latency(struct rq *rq) { return 0; }
#endif /* CONFIG_SCHED_DEBUG */
+#ifdef CONFIG_SMP
+static inline bool rq_overloaded(struct rq *rq)
+{
+ return rq->nr_running - rq->cfs.idle_h_nr_running > 1;
+}
+
+void update_overloaded_rq(struct rq *rq)
+{
+ struct sched_domain_shared *sds;
+ bool overloaded = rq_overloaded(rq);
+ int cpu = cpu_of(rq);
+
+ lockdep_assert_rq_held(rq);
+
+ if (rq->overloaded == overloaded)
+ return;
+
+ rcu_read_lock();
+ sds = rcu_dereference(per_cpu(sd_llc_shared, cpu));
+ if (unlikely(!sds))
+ goto unlock;
+
+ if (overloaded) {
+ cpumask_set_cpu(cpu, sdo_mask(sds));
+ atomic_inc(&sds->nr_overloaded_cpus);
+ } else {
+ cpumask_clear_cpu(cpu, sdo_mask(sds));
+ atomic_dec(&sds->nr_overloaded_cpus);
+ }
+
+ rq->overloaded = overloaded;
+unlock:
+ rcu_read_unlock();
+}
+#endif
+
/*
* This function gets called by the timer code, with HZ frequency.
* We call it with interrupts disabled.
@@ -5346,6 +5382,7 @@ void scheduler_tick(void)
resched_latency = cpu_resched_latency(rq);
calc_global_load_tick(rq);
sched_core_tick(rq);
+ update_overloaded_rq(rq);
rq_unlock(rq, &rf);
@@ -9578,6 +9615,7 @@ void __init sched_init(void)
rq->wake_stamp = jiffies;
rq->wake_avg_idle = rq->avg_idle;
rq->max_idle_balance_cost = sysctl_sched_migration_cost;
+ rq->overloaded = 0;
INIT_LIST_HEAD(&rq->cfs_tasks);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d4bd299d67ab..79b4ff24faee 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6323,7 +6323,9 @@ static inline int select_idle_smt(struct task_struct *p, struct sched_domain *sd
static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool has_idle_core, int target)
{
struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
- int i, cpu, idle_cpu = -1, nr = INT_MAX;
+ struct sched_domain_shared *sds = sd->shared;
+ int nr, nro, weight = sd->span_weight;
+ int i, cpu, idle_cpu = -1;
struct rq *this_rq = this_rq();
int this = smp_processor_id();
struct sched_domain *this_sd;
@@ -6333,7 +6335,23 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool
if (!this_sd)
return -1;
+ nro = atomic_read(&sds->nr_overloaded_cpus);
+ if (nro == weight)
+ goto out;
+
+ nr = min_t(int, weight, p->nr_cpus_allowed);
+
+ /*
+ * It's unlikely to find an idle cpu if the system is under
+ * heavy pressure, so skip searching to save a few cycles
+ * and relieve cache traffic.
+ */
+ if (weight - nro < (nr >> 4) && !has_idle_core)
+ return -1;
+
cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
+ if (nro > 1)
+ cpumask_andnot(cpus, cpus, sdo_mask(sds));
if (sched_feat(SIS_PROP) && !has_idle_core) {
u64 avg_cost, avg_idle, span_avg;
@@ -6354,7 +6372,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool
avg_idle = this_rq->wake_avg_idle;
avg_cost = this_sd->avg_scan_cost + 1;
- span_avg = sd->span_weight * avg_idle;
+ span_avg = weight * avg_idle;
if (span_avg > 4*avg_cost)
nr = div_u64(span_avg, avg_cost);
else
@@ -6378,9 +6396,6 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool
}
}
- if (has_idle_core)
- set_idle_cores(target, false);
-
if (sched_feat(SIS_PROP) && !has_idle_core) {
time = cpu_clock(this) - time;
@@ -6392,6 +6407,9 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool
update_avg(&this_sd->avg_scan_cost, time);
}
+out:
+ if (has_idle_core)
+ WRITE_ONCE(sds->has_idle_cores, 0);
return idle_cpu;
}
@@ -7904,6 +7922,7 @@ static struct task_struct *detach_one_task(struct lb_env *env)
continue;
detach_task(p, env);
+ update_overloaded_rq(env->src_rq);
/*
* Right now, this is only the second place where
@@ -8047,6 +8066,9 @@ static int detach_tasks(struct lb_env *env)
list_move(&p->se.group_node, tasks);
}
+ if (detached)
+ update_overloaded_rq(env->src_rq);
+
/*
* Right now, this is one of only two places we collect this stat
* so we can safely collect detach_one_task() stats here rather
@@ -8080,6 +8102,7 @@ static void attach_one_task(struct rq *rq, struct task_struct *p)
rq_lock(rq, &rf);
update_rq_clock(rq);
attach_task(rq, p);
+ update_overloaded_rq(rq);
rq_unlock(rq, &rf);
}
@@ -8090,20 +8113,22 @@ static void attach_one_task(struct rq *rq, struct task_struct *p)
static void attach_tasks(struct lb_env *env)
{
struct list_head *tasks = &env->tasks;
+ struct rq *rq = env->dst_rq;
struct task_struct *p;
struct rq_flags rf;
- rq_lock(env->dst_rq, &rf);
- update_rq_clock(env->dst_rq);
+ rq_lock(rq, &rf);
+ update_rq_clock(rq);
while (!list_empty(tasks)) {
p = list_first_entry(tasks, struct task_struct, se.group_node);
list_del_init(&p->se.group_node);
- attach_task(env->dst_rq, p);
+ attach_task(rq, p);
}
- rq_unlock(env->dst_rq, &rf);
+ update_overloaded_rq(rq);
+ rq_unlock(rq, &rf);
}
#ifdef CONFIG_NO_HZ_COMMON
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index ecb0d7052877..7b65c9046a75 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -433,6 +433,7 @@ static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
static void set_next_task_idle(struct rq *rq, struct task_struct *next, bool first)
{
update_idle_core(rq);
+ update_overloaded_rq(rq);
schedstat_inc(rq->sched_goidle);
}
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 8dccb34eb190..d2b6e65cc336 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -997,6 +997,7 @@ struct rq {
unsigned char nohz_idle_balance;
unsigned char idle_balance;
+ unsigned char overloaded;
unsigned long misfit_task_load;
@@ -1830,8 +1831,11 @@ extern int sched_update_scaling(void);
extern void flush_smp_call_function_from_idle(void);
+extern void update_overloaded_rq(struct rq *rq);
+
#else /* !CONFIG_SMP: */
static inline void flush_smp_call_function_from_idle(void) { }
+static inline void update_overloaded_rq(struct rq *rq) { }
#endif
#include "stats.h"
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 810750e62118..6d5291875275 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1620,6 +1620,8 @@ sd_init(struct sched_domain_topology_level *tl,
sd->shared = *per_cpu_ptr(sdd->sds, sd_id);
atomic_inc(&sd->shared->ref);
atomic_set(&sd->shared->nr_busy_cpus, sd_weight);
+ atomic_set(&sd->shared->nr_overloaded_cpus, 0);
+ cpumask_clear(sdo_mask(sd->shared));
}
sd->private = sdd;
@@ -2085,7 +2087,7 @@ static int __sdt_alloc(const struct cpumask *cpu_map)
*per_cpu_ptr(sdd->sd, j) = sd;
- sds = kzalloc_node(sizeof(struct sched_domain_shared),
+ sds = kzalloc_node(sizeof(struct sched_domain_shared) + cpumask_size(),
GFP_KERNEL, cpu_to_node(j));
if (!sds)
return -ENOMEM;
--
2.31.1