Currently, update_top_cache_domain() is called whenever schedule domain is
built or destroyed. But, the following
callpath shows that they're at the same callpath and can be avoided
update_top_cache_domain() while destroying schedule
domain and update only at the times of building schedule domains.
partition_sched_domains()
detach_destroy_domain()
cpu_attach_domain()
update_top_cache_domain()
build_sched_domains()
cpu_attach_domain()
update_top_cache_domain()
Signed-off-by: Rakib Mullick <rakib.mull...@gmail.com>
---
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b7c32cb..8c6fee4 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5102,8 +5102,8 @@ static void update_top_cache_domain(int cpu)
* Attach the domain 'sd' to 'cpu' as its base domain. Callers must
* hold the hotplug lock.
*/
-static void
-cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
+static void cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd,
+ int cpu, bool update_cache_domain)
{
struct rq *rq = cpu_rq(cpu);
struct sched_domain *tmp;
@@ -5138,7 +5138,8 @@ cpu_attach_domain(struct sched_domain *sd, struct
root_domain *rd, int cpu)
rcu_assign_pointer(rq->sd, sd);
destroy_sched_domains(tmp, cpu);
- update_top_cache_domain(cpu);
+ if (update_cache_domain)
+ update_top_cache_domain(cpu);
}
/* cpus with isolated domains */
@@ -6021,7 +6022,7 @@ static int build_sched_domains(const struct cpumask
*cpu_map,
rcu_read_lock();
for_each_cpu(i, cpu_map) {
sd = *per_cpu_ptr(d.sd, i);
- cpu_attach_domain(sd, d.rd, i);
+ cpu_attach_domain(sd, d.rd, i, 1);
}
rcu_read_unlock();
@@ -6109,7 +6110,7 @@ static void detach_destroy_domains(const struct cpumask
*cpu_map)
rcu_read_lock();
for_each_cpu(i, cpu_map)
- cpu_attach_domain(NULL, &def_root_domain, i);
+ cpu_attach_domain(NULL, &def_root_domain, i, 0);
rcu_read_unlock();
}
--
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