sched/core: Optimize SCHED_SMT

[cascardo/linux.git] / kernel / sched / fair.c

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 6b41589..87caf2b 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5357,7 +5357,7 @@ static inline bool test_idle_cores(int cpu, bool def)
  * Since SMT siblings share all cache levels, inspecting this limited remote
  * state should be fairly cheap.
  */
-void update_idle_core(struct rq *rq)
+void __update_idle_core(struct rq *rq)
 {
        int core = cpu_of(rq);
        int cpu;
@@ -5389,6 +5389,9 @@ static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int
        struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
        int core, cpu, wrap;
 
+       if (!static_branch_likely(&sched_smt_present))
+               return -1;
+
        if (!test_idle_cores(target, false))
                return -1;
 
@@ -5422,6 +5425,9 @@ static int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int t
 {
        int cpu;
 
+       if (!static_branch_likely(&sched_smt_present))
+               return -1;
+
        for_each_cpu(cpu, cpu_smt_mask(target)) {
                if (!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))
                        continue;